{ "pdf_info": [ { "para_blocks": [ { "bbox": [ 154, 173, 443, 203 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 150, 173, 445, 206 ], "spans": [ { "bbox": [ 150, 173, 445, 206 ], "type": "text", "content": "操作系统课程设计指导书", "score": 1.0 } ] } ] }, { "bbox": [ 236, 280, 366, 298 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 234, 280, 368, 301 ], "spans": [ { "bbox": [ 234, 280, 368, 301 ], "type": "text", "content": "赵伟华 刘真 张梅", "score": 1.0 } ] } ] }, { "bbox": [ 231, 592, 320, 609 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 230, 590, 322, 612 ], "spans": [ { "bbox": [ 230, 590, 322, 612 ], "type": "text", "content": "2017 年 08 月", "score": 1.0 } ] } ] }, { "bbox": [ 239, 624, 315, 640 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 238, 623, 317, 642 ], "spans": [ { "bbox": [ 238, 623, 317, 642 ], "type": "text", "content": "计算机学院", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 0 }, { "para_blocks": [ { "bbox": [ 184, 77, 418, 97 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 184, 74, 418, 100 ], "spans": [ { "bbox": [ 184, 74, 246, 100 ], "type": "text", "content": "第六章", "score": 1.0 }, { "bbox": [ 255, 75, 418, 99 ], "type": "text", "content": "linux 常用工具介绍", "score": 1.0 } ] } ] }, { "bbox": [ 114, 124, 301, 140 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 116, 123, 302, 142 ], "spans": [ { "bbox": [ 116, 123, 302, 142 ], "type": "text", "content": "6.1 查看 linux 源码内容工具", "score": 1.0 } ] } ] }, { "bbox": [ 86, 166, 505, 197 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 168, 505, 179 ], "spans": [ { "bbox": [ 110, 168, 505, 179 ], "type": "text", "content": "学习linux的实现原理时，经常需要查看某些数据结构的定义格式、某些内核函数的具", "score": 1.0 } ] }, { "bbox": [ 89, 185, 437, 198 ], "spans": [ { "bbox": [ 89, 185, 437, 198 ], "type": "text", "content": "体实现过程等，相关工具比较多，这里介绍 ctags 和 source insight 两种。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 206, 254, 221 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 114, 206, 253, 221 ], "spans": [ { "bbox": [ 114, 206, 253, 221 ], "type": "text", "content": "6.1 .1 通过相关网站查询", "score": 1.0 } ] } ] }, { "bbox": [ 107, 238, 320, 282 ], "type": "list", "angle": 0, "index": 7, "blocks": [ { "bbox": [ 108, 238, 268, 250 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 108, 235, 268, 253 ], "spans": [ { "bbox": [ 108, 235, 268, 253 ], "type": "text", "content": "1.网址 1：http://lxr.linux.no/", "score": 1.0 } ] } ] }, { "bbox": [ 107, 269, 320, 282 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 107, 267, 321, 285 ], "spans": [ { "bbox": [ 107, 267, 321, 285 ], "type": "text", "content": "2.网址 2：http://lxr.free-electrons.com/", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 113, 301, 220, 313 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 297, 221, 317 ], "spans": [ { "bbox": [ 114, 297, 174, 317 ], "type": "text", "content": "6.1.2 vim", "score": 1.0 }, { "bbox": [ 174, 301, 186, 312 ], "type": "inline_equation", "content": "\\mathbf { + }", "score": 0.62 }, { "bbox": [ 186, 297, 221, 317 ], "type": "text", "content": "ctags", "score": 1.0 } ] } ] }, { "bbox": [ 107, 327, 499, 341 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 326, 499, 341 ], "spans": [ { "bbox": [ 109, 326, 499, 341 ], "type": "text", "content": "在 vim 中安装插件 ctags 后，就可以在终端方便地使用 vi 命令查看 linux 源码内容了。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 349, 201, 364 ], "type": "title", "angle": 0, "index": 10, "lines": [ { "bbox": [ 108, 349, 202, 364 ], "spans": [ { "bbox": [ 108, 349, 202, 364 ], "type": "text", "content": "1. 安装 ctags 插件", "score": 1.0 } ] } ] }, { "bbox": [ 86, 376, 505, 424 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 109, 376, 506, 389 ], "spans": [ { "bbox": [ 109, 376, 506, 389 ], "type": "text", "content": "Ctags 插件的功能是遍历 linux 源码文件，为源码的变量/对象、结构体/类、函数/接口、宏", "score": 1.0 } ] }, { "bbox": [ 89, 395, 506, 407 ], "spans": [ { "bbox": [ 89, 395, 506, 407 ], "type": "text", "content": "等产生索引文件：tags 文件，以便快速定位这些内容。tags 文件也是 Taglist 和 OmniCppComplete", "score": 1.0 } ] }, { "bbox": [ 88, 412, 149, 426 ], "spans": [ { "bbox": [ 88, 412, 149, 426 ], "type": "text", "content": "工作的基础。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 429, 499, 443 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 428, 500, 444 ], "spans": [ { "bbox": [ 109, 428, 500, 444 ], "type": "text", "content": "有两种方法安装ctags 插件，一种是源码安装，一种是在ubuntu中使用apt-get安装。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 448, 270, 460 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 114, 447, 271, 463 ], "spans": [ { "bbox": [ 114, 447, 271, 463 ], "type": "text", "content": "（1）ubuntu 中使用 apt-get 安装：", "score": 1.0 } ] } ] }, { "bbox": [ 135, 466, 273, 479 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 135, 465, 276, 481 ], "spans": [ { "bbox": [ 135, 465, 276, 481 ], "type": "text", "content": "sudo apt-get install ctags", "score": 1.0 } ] } ] }, { "bbox": [ 113, 484, 204, 497 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 484, 205, 497 ], "spans": [ { "bbox": [ 114, 484, 205, 497 ], "type": "text", "content": "（2）下载源码安装：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 502, 504, 586 ], "type": "list", "angle": 0, "index": 20, "blocks": [ { "bbox": [ 86, 502, 504, 532 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 119, 500, 506, 516 ], "spans": [ { "bbox": [ 119, 500, 506, 516 ], "type": "text", "content": "1）从 http://prdownloads.sourceforge.net/ctags/ctags-5.8.tar.gz 下载 ctags", "score": 1.0 } ] }, { "bbox": [ 88, 518, 213, 534 ], "spans": [ { "bbox": [ 88, 518, 213, 534 ], "type": "text", "content": "源码包 ctags-5.8.tar.gz；", "score": 1.0 } ] } ] }, { "bbox": [ 128, 537, 413, 550 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 130, 535, 414, 552 ], "spans": [ { "bbox": [ 130, 535, 414, 552 ], "type": "text", "content": "或者从 http://ctags.sourceforge.net/下载 ctags 源代码包", "score": 1.0 } ] } ] }, { "bbox": [ 117, 555, 247, 567 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 120, 555, 246, 568 ], "spans": [ { "bbox": [ 120, 555, 246, 568 ], "type": "text", "content": "2）解压缩生成源代码目录；", "score": 1.0 } ] } ] }, { "bbox": [ 117, 573, 359, 586 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 119, 571, 360, 587 ], "spans": [ { "bbox": [ 119, 571, 360, 587 ], "type": "text", "content": "3）进入源代码目录，依次执行如下命令安装ctags：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "type": "code", "bbox": [ 149, 591, 252, 640 ], "blocks": [ { "bbox": [ 149, 591, 252, 640 ], "lines": [ { "bbox": [ 149, 591, 252, 640 ], "spans": [ { "bbox": [ 149, 591, 252, 640 ], "type": "text", "content": "$ ./configure $ make $ sudo make install" } ] } ], "index": 21, "angle": 0, "type": "code_body" } ], "index": 21, "sub_type": "code", "guess_lang": "shell" }, { "bbox": [ 108, 650, 217, 663 ], "type": "title", "angle": 0, "index": 22, "lines": [ { "bbox": [ 108, 647, 217, 665 ], "spans": [ { "bbox": [ 108, 647, 217, 665 ], "type": "text", "content": "1. 生成索引文件 tags", "score": 1.0 } ] } ] }, { "bbox": [ 108, 676, 273, 689 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 111, 677, 273, 689 ], "spans": [ { "bbox": [ 111, 677, 273, 689 ], "type": "text", "content": "从终端进入linux 源码目录，执行：", "score": 1.0 } ] } ] }, { "bbox": [ 128, 694, 227, 707 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 130, 694, 229, 708 ], "spans": [ { "bbox": [ 130, 694, 138, 707 ], "type": "inline_equation", "content": "\\$ 8", "score": 0.64 }, { "bbox": [ 138, 694, 229, 708 ], "type": "text", "content": "sudo ctags –R *", "score": 1.0 } ] } ] }, { "bbox": [ 108, 712, 500, 743 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 112, 710, 503, 726 ], "spans": [ { "bbox": [ 112, 710, 503, 726 ], "type": "text", "content": "“-R”标识递归创建，即包括 linux源代码根目录（当前目录）下的所有子目录；“*”", "score": 1.0 } ] }, { "bbox": [ 109, 730, 483, 743 ], "spans": [ { "bbox": [ 109, 730, 483, 743 ], "type": "text", "content": "表示所有文件。执行该命令后会在当前目录下生成一个“tags”文件，如图所示：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 1 }, { "para_blocks": [ { "type": "code", "bbox": [ 110, 75, 485, 160 ], "blocks": [ { "bbox": [ 110, 75, 485, 160 ], "lines": [ { "bbox": [ 110, 75, 485, 160 ], "spans": [ { "bbox": [ 110, 75, 485, 160 ], "type": "text", "content": "zwh@ubuntu:/usr/src/linux-4.4.19$ sudo ctags -R *\n[sudo] password for zwh:\nzwh@ubuntu:/usr/src/linux-4.4.19$ ls\narch crypto include kernel net security virt\nblock Documentation init lib README sound\ncerts drivers ipc MAINTAINERS REPORTING-BUGS tags\nCOPYING firmware Kbuild Makefile samples tools\nCREDITS fs Kconfig mm scripts usr\nzwh@ubuntu:/usr/src/linux-4.4.19$" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "shell" }, { "bbox": [ 86, 169, 505, 216 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 170, 505, 181 ], "spans": [ { "bbox": [ 110, 170, 505, 181 ], "type": "text", "content": "如果只是在linux 源代码目录下查询源码信息，则不需要修改vim的配置文件；否则如", "score": 1.0 } ] }, { "bbox": [ 89, 188, 505, 200 ], "spans": [ { "bbox": [ 89, 188, 505, 200 ], "type": "text", "content": "果希望在其他路径下也能查看，则必须使用sudo vim /etc/vim/vimrc 编辑这个文件，方法是", "score": 1.0 } ] }, { "bbox": [ 89, 206, 231, 216 ], "spans": [ { "bbox": [ 89, 206, 231, 216 ], "type": "text", "content": "在vimrc文件中添加如下内容：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 223, 271, 235 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 221, 272, 238 ], "spans": [ { "bbox": [ 108, 221, 272, 238 ], "type": "text", "content": "set tags=/usr/src/linux-4.4.19/tags;", "score": 1.0 } ] } ] }, { "bbox": [ 108, 241, 171, 251 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 108, 241, 173, 253 ], "spans": [ { "bbox": [ 108, 241, 173, 253 ], "type": "text", "content": "set autochdir", "score": 1.0 } ] } ] }, { "bbox": [ 107, 262, 303, 275 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 108, 261, 304, 277 ], "spans": [ { "bbox": [ 108, 261, 304, 277 ], "type": "text", "content": "2. 利用 ctags 文件查看 linux 源 码信息", "score": 1.0 } ] } ] }, { "bbox": [ 108, 288, 230, 301 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 289, 230, 301 ], "spans": [ { "bbox": [ 110, 289, 230, 301 ], "type": "text", "content": "最常用的命令有下面几个：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 306, 204, 318 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 305, 205, 322 ], "spans": [ { "bbox": [ 114, 305, 135, 322 ], "type": "text", "content": "（1）", "score": 1.0 }, { "bbox": [ 135, 306, 143, 319 ], "type": "inline_equation", "content": "\\$ 8", "score": 0.73 }, { "bbox": [ 143, 305, 205, 322 ], "type": "text", "content": "vi –t tag：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 323, 434, 336 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 110, 324, 436, 338 ], "spans": [ { "bbox": [ 110, 324, 436, 338 ], "type": "text", "content": "命令中的“tag”是要查看的变量名、数据结构名、函数名等，如执行：", "score": 1.0 } ] } ] }, { "bbox": [ 128, 342, 252, 354 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 130, 340, 254, 356 ], "spans": [ { "bbox": [ 130, 342, 138, 354 ], "type": "inline_equation", "content": "\\$ 8", "score": 0.66 }, { "bbox": [ 138, 340, 254, 356 ], "type": "text", "content": "vi –t effective_prio", "score": 1.0 } ] } ] }, { "bbox": [ 108, 359, 295, 371 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 359, 296, 373 ], "spans": [ { "bbox": [ 110, 359, 296, 373 ], "type": "text", "content": "则会显示 effective_prio()的实现源码：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 110, 377, 463, 491 ], "blocks": [ { "bbox": [ 110, 377, 463, 491 ], "lines": [ { "bbox": [ 110, 377, 463, 491 ], "spans": [ { "bbox": [ 110, 377, 463, 491 ], "type": "text", "content": "static int effective_prio(struct task_struct *p) { p->normal_prio = normal_prio(p); /* If we are RT tasks or we were boosted to RT priority, * keep the priority unchanged. Otherwise, update priority * to the normal priority: */ if (!rt_prio(p->prio)) return p->normal_prio; return p->prio; }" } ] } ], "index": 11, "angle": 0, "type": "code_body" } ], "index": 11, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 113, 502, 189, 513 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 501, 190, 516 ], "spans": [ { "bbox": [ 114, 501, 135, 516 ], "type": "text", "content": "（2）", "score": 1.0 }, { "bbox": [ 135, 502, 167, 514 ], "type": "inline_equation", "content": "\\operatorname { C t r l } + ]", "score": 0.59 }, { "bbox": [ 168, 501, 190, 516 ], "type": "text", "content": "命令", "score": 1.0 } ] } ] }, { "bbox": [ 86, 518, 499, 549 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 519, 501, 531 ], "spans": [ { "bbox": [ 109, 519, 501, 531 ], "type": "text", "content": "在vim中，将光标移动到要查看的变量名、数据结构名、函数名处，同时按下“Ctrl+]”", "score": 1.0 } ] }, { "bbox": [ 89, 537, 399, 549 ], "spans": [ { "bbox": [ 89, 537, 399, 549 ], "type": "text", "content": "键，则立即跳转到光标所在变量名、数据结构名、函数名的定义处。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 555, 192, 565 ], "type": "title", "angle": 0, "index": 14, "lines": [ { "bbox": [ 114, 554, 193, 568 ], "spans": [ { "bbox": [ 114, 554, 193, 568 ], "type": "text", "content": "（3）Ctrl+T 命令", "score": 1.0 } ] } ] }, { "bbox": [ 107, 571, 430, 584 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 109, 571, 431, 586 ], "spans": [ { "bbox": [ 109, 571, 431, 586 ], "type": "text", "content": "在vim中同时按下“Ctrl+T”键，则返回查找或跳转到前一次界面处。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 590, 171, 602 ], "type": "title", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 589, 172, 603 ], "spans": [ { "bbox": [ 114, 589, 172, 603 ], "type": "text", "content": "（4）ta命令", "score": 1.0 } ] } ] }, { "bbox": [ 108, 607, 498, 619 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 607, 499, 621 ], "spans": [ { "bbox": [ 109, 607, 499, 621 ], "type": "text", "content": "在vim中命令行下使用 ta命令，也能显示变量名、数据结构名、函数名的定义，如：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 626, 190, 638 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 108, 624, 191, 638 ], "spans": [ { "bbox": [ 108, 624, 191, 638 ], "type": "text", "content": ":ta normal_prio", "score": 1.0 } ] } ] }, { "bbox": [ 108, 643, 248, 655 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 110, 642, 249, 656 ], "spans": [ { "bbox": [ 110, 642, 249, 656 ], "type": "text", "content": "则显示 normal_prio()的定义：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 2 }, { "para_blocks": [ { "type": "code", "bbox": [ 110, 74, 388, 193 ], "blocks": [ { "bbox": [ 110, 74, 388, 193 ], "lines": [ { "bbox": [ 110, 74, 388, 193 ], "spans": [ { "bbox": [ 110, 74, 388, 193 ], "type": "text", "content": "static inline int normal_prio(struct task_struct *p) {\n int prio;\n if (task_has_DL_policy(p))\n prio = MAX_DL_PRIO-1;\n else if (task_has_rt_policy(p))\n prio = MAX_RT_PRIO-1 - p->rt_priority;\n else\n prio = __normal_prio(p);\n return prio;\n}" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 116, 201, 422, 214 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 117, 200, 423, 216 ], "spans": [ { "bbox": [ 117, 200, 423, 216 ], "type": "text", "content": "更多功能可通过命令 man ctags 或在 Vim 命令行下运行 help ctags 查询。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 240, 247, 253 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 114, 238, 248, 256 ], "spans": [ { "bbox": [ 114, 238, 248, 256 ], "type": "text", "content": "6.1.3 安装使用 Taglist", "score": 1.0 } ] } ] }, { "bbox": [ 86, 268, 502, 298 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 119, 268, 501, 280 ], "spans": [ { "bbox": [ 119, 268, 501, 280 ], "type": "text", "content": "Taglist 是 vim的一个插件，提供源码的结构化浏览功能，可将源码中定义的函数、变量、结", "score": 1.0 } ] }, { "bbox": [ 89, 286, 352, 297 ], "spans": [ { "bbox": [ 89, 286, 352, 297 ], "type": "text", "content": "构体等以树结构显示，层次关系一目了然，便于快速定位查看。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 306, 211, 320 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 306, 212, 321 ], "spans": [ { "bbox": [ 114, 306, 212, 321 ], "type": "text", "content": "1.安装 Taglist 插件", "score": 1.0 } ] } ] }, { "bbox": [ 86, 334, 503, 398 ], "type": "list", "angle": 0, "index": 8, "blocks": [ { "bbox": [ 86, 334, 458, 364 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 117, 333, 458, 348 ], "spans": [ { "bbox": [ 117, 333, 458, 348 ], "type": "text", "content": "1）从 http://www.vim.org/scripts/script.php?script_id=273 下载安装包，也可以从", "score": 1.0 } ] }, { "bbox": [ 88, 351, 298, 365 ], "spans": [ { "bbox": [ 88, 351, 298, 365 ], "type": "text", "content": "http://vim-taglist.sourceforge.net/index.html 下载。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 370, 503, 398 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 117, 371, 504, 380 ], "spans": [ { "bbox": [ 117, 371, 504, 380 ], "type": "text", "content": "2）以 root 用户进入/etc/vim 目录,将 Taglist 安装包复制到该目录下并解压，解压后会在当前目", "score": 1.0 } ] }, { "bbox": [ 88, 388, 291, 399 ], "spans": [ { "bbox": [ 88, 388, 291, 399 ], "type": "text", "content": "录下生成两个子目录：plugin 和 doc，如图所示：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "type": "code", "bbox": [ 133, 401, 376, 460 ], "blocks": [ { "bbox": [ 133, 401, 376, 460 ], "lines": [ { "bbox": [ 133, 401, 376, 460 ], "spans": [ { "bbox": [ 133, 401, 376, 460 ], "type": "text", "content": "root@ubuntu:/etc/vim# unzip taglist_46.zip \nArchive: taglist_46.zip \ninflating: plugin/taglist.vim \ninflating: doc/taglist.txt \nroot@ubuntu:/etc/vim# ls \ndoc plugin taglist_46.zip vimrc vimrc.tiny" } ] } ], "index": 9, "angle": 0, "type": "code_body" } ], "index": 9, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 86, 467, 504, 514 ], "type": "list", "angle": 0, "index": 12, "blocks": [ { "bbox": [ 86, 467, 504, 497 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 118, 467, 504, 478 ], "spans": [ { "bbox": [ 118, 467, 504, 478 ], "type": "text", "content": "3）进入/etc/vim/doc 目录，运行 vim，执行\"helptags\"命令。该命令是将 doc 下的帮助文档加", "score": 1.0 } ] }, { "bbox": [ 88, 485, 478, 497 ], "spans": [ { "bbox": [ 88, 485, 478, 497 ], "type": "text", "content": "入到 Vim 的帮助主题中，这样我们就可以通过在 Vim 中运行“help taglist.txt”查看 taglist 帮助。", "score": 1.0 } ] } ] }, { "bbox": [ 115, 502, 462, 514 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 116, 502, 463, 514 ], "spans": [ { "bbox": [ 116, 502, 463, 514 ], "type": "text", "content": "4）打开 vim的配置文件/etc/vim/vimrc，加入以下两行内容，则安装工作就完成了：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 148, 519, 477, 532 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 149, 518, 478, 534 ], "spans": [ { "bbox": [ 149, 518, 257, 534 ], "type": "text", "content": "let Tlist_Show_One_File", "score": 1.0 }, { "bbox": [ 257, 520, 270, 531 ], "type": "inline_equation", "content": "{ \\mathop { : = } } 1", "score": 0.54 }, { "bbox": [ 270, 518, 478, 534 ], "type": "text", "content": "//不同时显示多个文件的 tag，只显示一个", "score": 1.0 } ] } ] }, { "bbox": [ 149, 537, 461, 550 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 150, 536, 462, 551 ], "spans": [ { "bbox": [ 150, 536, 268, 551 ], "type": "text", "content": "let Tlist_Exit_OnlyWindow", "score": 1.0 }, { "bbox": [ 269, 538, 282, 549 ], "type": "inline_equation", "content": "^ { - 1 }", "score": 0.66 }, { "bbox": [ 282, 536, 462, 551 ], "type": "text", "content": "//taglist 为最后一个窗口时，退出 vim", "score": 1.0 } ] } ] }, { "bbox": [ 149, 556, 398, 568 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 151, 555, 399, 570 ], "spans": [ { "bbox": [ 151, 555, 215, 570 ], "type": "text", "content": "Tlist_Sort_Type", "score": 1.0 }, { "bbox": [ 215, 559, 222, 566 ], "type": "inline_equation", "content": "=", "score": 0.7 }, { "bbox": [ 223, 555, 246, 570 ], "type": "text", "content": "name", "score": 1.0 }, { "bbox": [ 279, 557, 399, 569 ], "type": "text", "content": "//使 taglist 以 tag 名字进行排序", "score": 1.0 } ] } ] }, { "bbox": [ 119, 572, 416, 585 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 121, 571, 417, 587 ], "spans": [ { "bbox": [ 121, 571, 417, 587 ], "type": "text", "content": "还有许多其他的设置选项，请参考帮助文档:help taglist.txt。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 594, 206, 608 ], "type": "title", "angle": 0, "index": 17, "lines": [ { "bbox": [ 108, 594, 207, 608 ], "spans": [ { "bbox": [ 108, 594, 207, 608 ], "type": "text", "content": "2.使用 Taglist 插件", "score": 1.0 } ] } ] }, { "bbox": [ 110, 619, 286, 632 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 112, 618, 287, 634 ], "spans": [ { "bbox": [ 112, 618, 287, 634 ], "type": "text", "content": "（1）在 vim 中打开 taglist 窗口：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 636, 472, 650 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 636, 473, 650 ], "spans": [ { "bbox": [ 109, 636, 473, 650 ], "type": "text", "content": "在vim命令方式下运行以下三个命令之一都可以打开 taglist窗口，如图所示：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 129, 653, 196, 698 ], "blocks": [ { "bbox": [ 129, 653, 196, 698 ], "lines": [ { "bbox": [ 129, 653, 196, 698 ], "spans": [ { "bbox": [ 129, 653, 196, 698 ], "type": "text", "content": ":Tlist :Tlist0pen :TlistToggle" } ] } ], "index": 20, "angle": 0, "type": "code_body" } ], "index": 20, "sub_type": "code", "guess_lang": "autohotkey" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 3 }, { "para_blocks": [ { "type": "image", "bbox": [ 91, 75, 505, 176 ], "blocks": [ { "bbox": [ 91, 75, 505, 176 ], "lines": [ { "bbox": [ 91, 75, 505, 176 ], "spans": [ { "bbox": [ 91, 75, 505, 176 ], "type": "image", "image_path": "55f641d6940a3ce061008766baa1ba4c546250f525a465e8df10f9bd6ced8979.jpg" } ] } ], "index": 1, "angle": 0, "type": "image_body" } ], "index": 1 }, { "bbox": [ 86, 183, 505, 227 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 183, 505, 195 ], "spans": [ { "bbox": [ 110, 183, 505, 195 ], "type": "text", "content": "图中右边窗口是文件编辑窗口，左边是 taglist 窗口。在taglist窗口中分类显示右边", "score": 1.0 } ] }, { "bbox": [ 88, 198, 506, 213 ], "spans": [ { "bbox": [ 88, 198, 506, 213 ], "type": "text", "content": "文件中所有的 tag（分类依次为宏定义、数据结构、变量、函数），并且每类 tag 都按各 tag", "score": 1.0 } ] }, { "bbox": [ 89, 215, 283, 227 ], "spans": [ { "bbox": [ 89, 215, 283, 227 ], "type": "text", "content": "在文件中出现的先后顺序排序，如图所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 91, 232, 506, 301 ], "blocks": [ { "bbox": [ 91, 232, 506, 301 ], "lines": [ { "bbox": [ 91, 232, 506, 301 ], "spans": [ { "bbox": [ 91, 232, 506, 301 ], "type": "image", "image_path": "dce8c4e53bc714f4f55eec82fded2a9e3896d366bcaab3d959e04c36d99c3fba.jpg" } ] } ], "index": 3, "angle": 0, "type": "image_body" } ], "index": 3 }, { "type": "image", "bbox": [ 91, 309, 506, 349 ], "blocks": [ { "bbox": [ 91, 309, 506, 349 ], "lines": [ { "bbox": [ 91, 309, 506, 349 ], "spans": [ { "bbox": [ 91, 309, 506, 349 ], "type": "image", "image_path": "6469cb9dfa4d70014ba7dda7cff09ad369d02f55d440934a939a1305983a020b.jpg" } ] } ], "index": 4, "angle": 0, "type": "image_body" } ], "index": 4 }, { "type": "image", "bbox": [ 91, 358, 506, 456 ], "blocks": [ { "bbox": [ 91, 358, 506, 456 ], "lines": [ { "bbox": [ 91, 358, 506, 456 ], "spans": [ { "bbox": [ 91, 358, 506, 456 ], "type": "image", "image_path": "9f6aa32b5761b70f4ec343fdba29ff0f71876766038e13836425ac5dd421decd.jpg" } ] } ], "index": 5, "angle": 0, "type": "image_body" } ], "index": 5 }, { "bbox": [ 91, 481, 204, 492 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 94, 480, 205, 494 ], "spans": [ { "bbox": [ 94, 480, 205, 494 ], "type": "text", "content": "（2）关闭 taglist 窗口：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 496, 445, 508 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 88, 495, 446, 510 ], "spans": [ { "bbox": [ 88, 495, 446, 510 ], "type": "text", "content": "在vim命令方式下再次运行上述（1）中三个命令之一，则关闭taglist窗口。", "score": 1.0 } ] } ] }, { "bbox": [ 92, 512, 272, 524 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 93, 512, 274, 525 ], "spans": [ { "bbox": [ 93, 512, 274, 525 ], "type": "text", "content": "（3） 在taglist窗口中常用的快捷键：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 528, 467, 698 ], "type": "list", "angle": 0, "index": 20, "blocks": [ { "bbox": [ 108, 528, 384, 539 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 528, 385, 540 ], "spans": [ { "bbox": [ 109, 528, 385, 540 ], "type": "text", "content": "1）Ctrl+ww 在taglist窗口和文件编辑窗口之间切换焦点", "score": 1.0 } ] } ] }, { "bbox": [ 107, 544, 467, 556 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 108, 544, 469, 558 ], "spans": [ { "bbox": [ 108, 544, 124, 558 ], "type": "text", "content": "2）", "score": 1.0 }, { "bbox": [ 124, 544, 167, 556 ], "type": "inline_equation", "content": "\\langle \\mathrm { C t r } 1 \\rangle + ]", "score": 0.69 }, { "bbox": [ 168, 544, 469, 558 ], "type": "text", "content": "跳转到光标所在 tag 的定义位置；用鼠标双击此 tag 功能相同", "score": 1.0 } ] } ] }, { "bbox": [ 108, 560, 387, 572 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 107, 558, 389, 575 ], "spans": [ { "bbox": [ 107, 558, 135, 575 ], "type": "text", "content": "3）o", "score": 1.0 }, { "bbox": [ 172, 560, 389, 574 ], "type": "text", "content": "在一个新窗口中显示光标所在 tag 的定义位置；", "score": 1.0 } ] } ] }, { "bbox": [ 108, 576, 304, 588 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 575, 305, 590 ], "spans": [ { "bbox": [ 108, 575, 305, 590 ], "type": "text", "content": "4） 显示光标下 tag 的原型定义；", "score": 1.0 } ] } ] }, { "bbox": [ 108, 592, 298, 603 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 107, 589, 299, 608 ], "spans": [ { "bbox": [ 107, 589, 136, 608 ], "type": "text", "content": "5）u", "score": 1.0 }, { "bbox": [ 172, 590, 299, 607 ], "type": "text", "content": "更新 taglist 窗口中的 tag", "score": 1.0 } ] } ] }, { "bbox": [ 108, 607, 415, 619 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 108, 607, 416, 622 ], "spans": [ { "bbox": [ 108, 607, 135, 622 ], "type": "text", "content": "6）s", "score": 1.0 }, { "bbox": [ 173, 608, 416, 620 ], "type": "text", "content": "更改排序方式，在按名字排序和按出现顺序排序间切", "score": 1.0 } ] } ] }, { "bbox": [ 108, 624, 389, 636 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 107, 621, 391, 640 ], "spans": [ { "bbox": [ 107, 621, 136, 640 ], "type": "text", "content": "7）x", "score": 1.0 }, { "bbox": [ 172, 623, 391, 639 ], "type": "text", "content": "taglist 窗口放大和缩小，方便查看较长的 tag", "score": 1.0 } ] } ] }, { "bbox": [ 108, 639, 247, 651 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 107, 637, 248, 655 ], "spans": [ { "bbox": [ 107, 637, 139, 655 ], "type": "text", "content": "8）[[", "score": 1.0 }, { "bbox": [ 172, 640, 248, 652 ], "type": "text", "content": "跳到前一个文件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 655, 247, 667 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 107, 653, 248, 671 ], "spans": [ { "bbox": [ 107, 653, 139, 671 ], "type": "text", "content": "9）]]", "score": 1.0 }, { "bbox": [ 171, 655, 248, 668 ], "type": "text", "content": "跳到后一个文件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 671, 257, 683 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 107, 668, 259, 687 ], "spans": [ { "bbox": [ 107, 668, 136, 687 ], "type": "text", "content": "9）q", "score": 1.0 }, { "bbox": [ 172, 670, 259, 686 ], "type": "text", "content": "关闭 taglist 窗口", "score": 1.0 } ] } ] }, { "bbox": [ 108, 687, 216, 698 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 686, 217, 701 ], "spans": [ { "bbox": [ 109, 686, 155, 701 ], "type": "text", "content": "10）", "score": 1.0 }, { "bbox": [ 172, 686, 217, 701 ], "type": "text", "content": "显示帮助", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 113, 709, 241, 723 ], "type": "title", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 707, 242, 725 ], "spans": [ { "bbox": [ 114, 707, 242, 725 ], "type": "text", "content": "6.1.4 安装使用 Cscope", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 4 }, { "para_blocks": [ { "bbox": [ 86, 74, 489, 120 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 74, 489, 86 ], "spans": [ { "bbox": [ 109, 74, 489, 86 ], "type": "text", "content": "通过Cscope可以很方便地找到某个函数或变量的定义位置、被调用的位置等信息。", "score": 1.0 } ] }, { "bbox": [ 88, 90, 366, 102 ], "spans": [ { "bbox": [ 88, 90, 366, 102 ], "type": "text", "content": "Cscope已经是Vim的标准特性，默认都有支持，官方网址为", "score": 1.0 } ] }, { "bbox": [ 88, 105, 254, 120 ], "spans": [ { "bbox": [ 88, 105, 254, 120 ], "type": "text", "content": "http://cscope.sourceforge.net/。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 134, 210, 148 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 133, 210, 149 ], "spans": [ { "bbox": [ 109, 133, 210, 149 ], "type": "text", "content": "1． 安装 Cscope 插件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 165, 228, 178 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 163, 229, 179 ], "spans": [ { "bbox": [ 109, 163, 229, 179 ], "type": "text", "content": "在 ubuntu 下安装 Cscope：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 181, 301, 194 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 179, 301, 196 ], "spans": [ { "bbox": [ 109, 179, 301, 196 ], "type": "text", "content": "直接运行命令：apt-get install cscope", "score": 1.0 } ] } ] }, { "bbox": [ 108, 197, 180, 209 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 197, 179, 210 ], "spans": [ { "bbox": [ 110, 197, 179, 210 ], "type": "text", "content": "使用源码安装：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 213, 505, 243 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 212, 506, 227 ], "spans": [ { "bbox": [ 110, 212, 506, 227 ], "type": "text", "content": "从 http://cscope.sourceforge.net/下载 Cscope 源代码包编译安装，步骤同 Ctags 安", "score": 1.0 } ] }, { "bbox": [ 87, 226, 129, 243 ], "spans": [ { "bbox": [ 87, 226, 129, 243 ], "type": "text", "content": "装过程。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 257, 268, 271 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 108, 256, 267, 272 ], "spans": [ { "bbox": [ 108, 256, 267, 272 ], "type": "text", "content": "2． 以 root 身份配置 Cscope 插件", "score": 1.0 } ] } ] }, { "bbox": [ 87, 288, 500, 333 ], "type": "list", "angle": 0, "index": 10, "blocks": [ { "bbox": [ 87, 288, 500, 317 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 108, 286, 500, 303 ], "spans": [ { "bbox": [ 108, 286, 500, 303 ], "type": "text", "content": "1）下载 http://cscope.sourceforge.net/cscope_maps.vim 文件到/etc/vim/plugin", "score": 1.0 } ] }, { "bbox": [ 88, 301, 127, 318 ], "spans": [ { "bbox": [ 88, 301, 127, 318 ], "type": "text", "content": "目录中；", "score": 1.0 } ] } ] }, { "bbox": [ 108, 320, 242, 333 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 320, 242, 334 ], "spans": [ { "bbox": [ 109, 320, 242, 334 ], "type": "text", "content": "2）生成 cscope 数据库文件：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 336, 294, 349 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 336, 294, 349 ], "spans": [ { "bbox": [ 110, 336, 294, 349 ], "type": "text", "content": "进入linux源码根目录，执行下面命令：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 353, 186, 364 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 351, 186, 366 ], "spans": [ { "bbox": [ 108, 351, 186, 366 ], "type": "text", "content": "#cscope -Rbqk", "score": 1.0 } ] } ] }, { "bbox": [ 108, 367, 493, 380 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 108, 365, 495, 383 ], "spans": [ { "bbox": [ 108, 365, 495, 383 ], "type": "text", "content": "该命令将生成三个文件：cscope.out, cscope.in.out, cscope.po.out，如图所示：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 88, 396, 508, 454 ], "blocks": [ { "bbox": [ 88, 396, 508, 454 ], "lines": [ { "bbox": [ 88, 396, 508, 454 ], "spans": [ { "bbox": [ 88, 396, 508, 454 ], "type": "text", "content": "root@ubuntu:/home/zwh/linux-2.6.24#sccope-Rbkq root@ubuntu:/home/zwh/linux-2.6.24# ls arch cscope.in.out fs kernel net security block cscope.out include lib README sound COPYING cscope.po.out init MAINTAINERS REPORTING-BUGS tags" } ] } ], "index": 14, "angle": 0, "type": "code_body" } ], "index": 14, "sub_type": "code", "guess_lang": "batch" }, { "bbox": [ 86, 474, 495, 502 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 473, 495, 487 ], "spans": [ { "bbox": [ 110, 473, 495, 487 ], "type": "text", "content": "其中cscope.out 是基本的符号索引，后两个文件是使用\"-q\"选项生成的，可以加快", "score": 1.0 } ] }, { "bbox": [ 88, 490, 321, 503 ], "spans": [ { "bbox": [ 88, 490, 321, 503 ], "type": "text", "content": "cscope的索引速度。cscope 命令的参数含义如下：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 506, 505, 613 ], "type": "list", "angle": 0, "index": 22, "blocks": [ { "bbox": [ 113, 506, 337, 518 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 506, 337, 518 ], "spans": [ { "bbox": [ 114, 506, 337, 518 ], "type": "text", "content": "-R: 在生成索引文件时，搜索子目录树中的代码", "score": 1.0 } ] } ] }, { "bbox": [ 113, 521, 322, 534 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 114, 521, 321, 535 ], "spans": [ { "bbox": [ 114, 521, 321, 535 ], "type": "text", "content": "-b: 只生成索引文件，不进入 cscope的界面", "score": 1.0 } ] } ] }, { "bbox": [ 113, 538, 345, 550 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 114, 536, 346, 552 ], "spans": [ { "bbox": [ 114, 536, 346, 552 ], "type": "text", "content": "-d: 只调出 cscope gui 界面，不跟新 cscope.out", "score": 1.0 } ] } ] }, { "bbox": [ 113, 553, 351, 565 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 115, 553, 350, 566 ], "spans": [ { "bbox": [ 115, 553, 350, 566 ], "type": "text", "content": "-k: 在生成索引文件时，不搜索/usr/include 目录", "score": 1.0 } ] } ] }, { "bbox": [ 113, 569, 458, 582 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 114, 568, 459, 584 ], "spans": [ { "bbox": [ 114, 568, 459, 584 ], "type": "text", "content": "-q: 生成 cscope.in.out 和 cscope.po.out 文件，加快 cscope 的索引速度", "score": 1.0 } ] } ] }, { "bbox": [ 86, 585, 505, 613 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 585, 505, 598 ], "spans": [ { "bbox": [ 114, 585, 505, 598 ], "type": "text", "content": "-i: 如果保存文件列表的文件名不是 cscope.files时，需要加此选项告诉 cscope到", "score": 1.0 } ] }, { "bbox": [ 89, 601, 405, 613 ], "spans": [ { "bbox": [ 89, 601, 405, 613 ], "type": "text", "content": "哪儿去找源文件列表。可以使用\"-\"，表示由标准输入获得文件列表。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 617, 502, 693 ], "type": "list", "angle": 0, "index": 27, "blocks": [ { "bbox": [ 113, 617, 318, 629 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 116, 617, 318, 629 ], "spans": [ { "bbox": [ 116, 617, 318, 629 ], "type": "text", "content": "-I dir: 在-I选项指出的目录中查找头文件", "score": 1.0 } ] } ] }, { "bbox": [ 113, 633, 316, 645 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 114, 633, 315, 645 ], "spans": [ { "bbox": [ 114, 633, 315, 645 ], "type": "text", "content": "-u: 扫描所有文件，重新生成交叉索引文件", "score": 1.0 } ] } ] }, { "bbox": [ 113, 649, 232, 661 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 116, 649, 232, 661 ], "spans": [ { "bbox": [ 116, 649, 232, 661 ], "type": "text", "content": "-C: 在搜索时忽略大小写", "score": 1.0 } ] } ] }, { "bbox": [ 86, 664, 502, 693 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 116, 665, 502, 677 ], "spans": [ { "bbox": [ 116, 665, 502, 677 ], "type": "text", "content": "-P path: 在以相对路径表示的文件前加上 path，这样，你不用切换到你数据库文件", "score": 1.0 } ] }, { "bbox": [ 89, 681, 221, 693 ], "spans": [ { "bbox": [ 89, 681, 221, 693 ], "type": "text", "content": "所在的目录也可以使用它了。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 696, 238, 709 ], "type": "title", "angle": 0, "index": 28, "lines": [ { "bbox": [ 108, 696, 238, 710 ], "spans": [ { "bbox": [ 108, 696, 238, 710 ], "type": "text", "content": "3）载入cscope数据库文件", "score": 1.0 } ] } ] }, { "bbox": [ 86, 712, 494, 741 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 110, 712, 495, 724 ], "spans": [ { "bbox": [ 110, 712, 495, 724 ], "type": "text", "content": "使用cscope之前，需将前面生成的数据库文件载入到 vim中。如果之前已经下载过", "score": 1.0 } ] }, { "bbox": [ 88, 729, 395, 740 ], "spans": [ { "bbox": [ 88, 729, 395, 740 ], "type": "text", "content": "cscope_maps.vim 文件到/etc/vim/plugin 目录下，可忽略这一步。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 5 }, { "para_blocks": [ { "bbox": [ 86, 74, 505, 102 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 74, 506, 88 ], "spans": [ { "bbox": [ 109, 74, 506, 88 ], "type": "text", "content": "注意：生成的 cscope.out 和 tags 文件要在打开 vim 所在的文件夹，否则 vim 无法找到", "score": 1.0 } ] }, { "bbox": [ 89, 89, 158, 103 ], "spans": [ { "bbox": [ 89, 89, 158, 103 ], "type": "text", "content": "相关符号信息。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 105, 358, 118 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 106, 357, 119 ], "spans": [ { "bbox": [ 110, 106, 357, 119 ], "type": "text", "content": "进入 linux 源码根目录，在 vim 中运行以下命令即可：", "score": 1.0 } ] } ] }, { "bbox": [ 145, 122, 269, 134 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 145, 121, 269, 136 ], "spans": [ { "bbox": [ 145, 121, 269, 136 ], "type": "text", "content": ": cscope add cscope.out", "score": 1.0 } ] } ] }, { "bbox": [ 113, 137, 284, 150 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 114, 136, 284, 152 ], "spans": [ { "bbox": [ 114, 136, 284, 152 ], "type": "text", "content": "到这里，就可以开始使用 Cscope 了。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 165, 210, 179 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 108, 165, 210, 180 ], "spans": [ { "bbox": [ 108, 165, 210, 180 ], "type": "text", "content": "3． 使用 Cscope 插件", "score": 1.0 } ] } ] }, { "bbox": [ 107, 197, 348, 209 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 108, 196, 350, 211 ], "spans": [ { "bbox": [ 108, 196, 350, 211 ], "type": "text", "content": "Cscope 的查看命令都是在 vim 的命令方式下运行的。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 213, 196, 226 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 108, 212, 198, 227 ], "spans": [ { "bbox": [ 108, 212, 198, 227 ], "type": "text", "content": "cscope find 命令：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 228, 503, 257 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 228, 504, 242 ], "spans": [ { "bbox": [ 109, 228, 504, 242 ], "type": "text", "content": "在vim中添加cscope数据库文件后，就可以调用\"cscope find\"命令查找源码相关内容，", "score": 1.0 } ] }, { "bbox": [ 88, 243, 500, 258 ], "spans": [ { "bbox": [ 88, 243, 500, 258 ], "type": "text", "content": "如函数、变量、数据结构的定义及调用情况。vim支持 8种 cscope的查询功能，描述如下：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 260, 401, 274 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 260, 399, 274 ], "spans": [ { "bbox": [ 109, 260, 399, 274 ], "type": "text", "content": "s: 查找C语言符号，即查找函数名、宏、枚举值等出现的地方", "score": 1.0 } ] } ] }, { "bbox": [ 123, 276, 426, 290 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 124, 275, 427, 291 ], "spans": [ { "bbox": [ 124, 275, 427, 291 ], "type": "text", "content": "g: 查找函数、宏、枚举等定义的位置，类似 ctags 所提供的功能", "score": 1.0 } ] } ] }, { "bbox": [ 108, 292, 232, 305 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 109, 292, 232, 305 ], "spans": [ { "bbox": [ 109, 292, 232, 305 ], "type": "text", "content": "d: 查找本函数调用的函数", "score": 1.0 } ] } ] }, { "bbox": [ 108, 308, 232, 321 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 308, 232, 321 ], "spans": [ { "bbox": [ 109, 308, 232, 321 ], "type": "text", "content": "c: 查找调用本函数的函数", "score": 1.0 } ] } ] }, { "bbox": [ 108, 324, 210, 336 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 324, 210, 337 ], "spans": [ { "bbox": [ 109, 324, 210, 337 ], "type": "text", "content": "t: 查找指定的字符串", "score": 1.0 } ] } ] }, { "bbox": [ 107, 339, 388, 353 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 339, 389, 354 ], "spans": [ { "bbox": [ 109, 339, 389, 354 ], "type": "text", "content": "e: 查找 egrep 模式，相当于 egrep 功能，但查找速度快多了", "score": 1.0 } ] } ] }, { "bbox": [ 107, 355, 311, 368 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 109, 356, 310, 370 ], "spans": [ { "bbox": [ 109, 356, 310, 370 ], "type": "text", "content": "f: 查找并打开文件，类似 vim 的 find 功能", "score": 1.0 } ] } ] }, { "bbox": [ 108, 371, 232, 384 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 110, 372, 232, 384 ], "spans": [ { "bbox": [ 110, 372, 232, 384 ], "type": "text", "content": "i: 查找包含本文件的文件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 403, 179, 416 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 403, 179, 417 ], "spans": [ { "bbox": [ 109, 403, 179, 417 ], "type": "text", "content": "命令运用举例：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 419, 272, 432 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 110, 419, 273, 432 ], "spans": [ { "bbox": [ 110, 419, 273, 432 ], "type": "text", "content": "查看函数、宏、枚举等的定义位置：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 435, 284, 448 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 435, 285, 448 ], "spans": [ { "bbox": [ 109, 435, 285, 448 ], "type": "text", "content": ":cscope find g 函数（宏、枚举）名", "score": 1.0 } ] } ] }, { "bbox": [ 107, 452, 284, 464 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 109, 451, 285, 465 ], "spans": [ { "bbox": [ 109, 451, 285, 465 ], "type": "text", "content": "或：:cs find g 函数（宏、枚举）名", "score": 1.0 } ] } ] }, { "bbox": [ 107, 467, 430, 480 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 110, 467, 431, 481 ], "spans": [ { "bbox": [ 110, 467, 431, 481 ], "type": "text", "content": "如执行：cscope find g effective_prio，将显示该函数的实现源码。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 483, 272, 495 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 109, 483, 273, 496 ], "spans": [ { "bbox": [ 109, 483, 273, 496 ], "type": "text", "content": "查看函数、宏、枚举等的调用位置：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 499, 284, 511 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 109, 499, 285, 512 ], "spans": [ { "bbox": [ 109, 499, 285, 512 ], "type": "text", "content": ":cscope find c 函数（宏、枚举）名", "score": 1.0 } ] } ] }, { "bbox": [ 108, 514, 284, 527 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 108, 513, 285, 528 ], "spans": [ { "bbox": [ 108, 513, 285, 528 ], "type": "text", "content": "或：:cs find c 函数（宏、枚举）名", "score": 1.0 } ] } ] }, { "bbox": [ 86, 530, 498, 559 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 109, 528, 500, 544 ], "spans": [ { "bbox": [ 109, 528, 500, 544 ], "type": "text", "content": "如执行：cscope find c effective_prio，将显示所有调用该函数（宏、枚举）的位置，", "score": 1.0 } ] }, { "bbox": [ 88, 545, 138, 560 ], "spans": [ { "bbox": [ 88, 545, 138, 560 ], "type": "text", "content": "如图所示：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 171, 576, 423, 650 ], "blocks": [ { "bbox": [ 171, 576, 423, 650 ], "lines": [ { "bbox": [ 171, 576, 423, 650 ], "spans": [ { "bbox": [ 171, 576, 423, 650 ], "type": "text", "content": "Cscope tag: effective_priorio\n# line filename / context / line\n1 1761 kernel/sched.c <prio = effective_prio(p);\n2 4098 kernel/sched.c <> p->prio = effective_prio(p);\nType number and (empty Cancelcs):" } ] } ], "index": 26, "angle": 0, "type": "code_body" } ], "index": 26, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 108, 668, 284, 681 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 110, 669, 284, 682 ], "spans": [ { "bbox": [ 110, 669, 284, 682 ], "type": "text", "content": "其他命令选项的功能请读者自行实践。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 684, 224, 697 ], "type": "title", "angle": 0, "index": 28, "lines": [ { "bbox": [ 108, 684, 224, 698 ], "spans": [ { "bbox": [ 108, 684, 224, 698 ], "type": "text", "content": "3）Cscope 中常用快捷键", "score": 1.0 } ] } ] }, { "bbox": [ 86, 700, 503, 728 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 110, 700, 505, 713 ], "spans": [ { "bbox": [ 110, 700, 505, 713 ], "type": "text", "content": "在cscope_maps.vim文件中定义了一组快捷键执行前面的命令，具体使用方法请读者自", "score": 1.0 } ] }, { "bbox": [ 88, 716, 149, 729 ], "spans": [ { "bbox": [ 88, 716, 149, 729 ], "type": "text", "content": "行上机实践。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 732, 204, 744 ], "type": "title", "angle": 0, "index": 30, "lines": [ { "bbox": [ 109, 731, 205, 745 ], "spans": [ { "bbox": [ 109, 731, 205, 745 ], "type": "text", "content": "4）返回上一次界面：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 747, 273, 760 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 109, 748, 274, 761 ], "spans": [ { "bbox": [ 109, 748, 274, 761 ], "type": "text", "content": "快捷键“ctrl+t”返回上一次界面。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 6 }, { "para_blocks": [ { "bbox": [ 108, 74, 456, 88 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 108, 73, 458, 89 ], "spans": [ { "bbox": [ 108, 73, 458, 89 ], "type": "text", "content": "更多功能可通过命令 man cscope 或在 Vim 命令行下运行 help cscope 查询。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 106, 196, 118 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 88, 105, 196, 120 ], "spans": [ { "bbox": [ 88, 105, 196, 120 ], "type": "text", "content": "6.1.5 source insight", "score": 1.0 } ] } ] }, { "bbox": [ 86, 136, 502, 164 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 137, 502, 148 ], "spans": [ { "bbox": [ 110, 137, 502, 148 ], "type": "text", "content": "Source insight是一款 Windows下的面向项目开发的代码编辑浏览器，它可以自动同", "score": 1.0 } ] }, { "bbox": [ 88, 151, 369, 163 ], "spans": [ { "bbox": [ 88, 151, 369, 163 ], "type": "text", "content": "步分析相关源码，为我们的开发及源码分析提供了很大便利。", "score": 1.0 } ] } ] }, { "bbox": [ 87, 179, 223, 193 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 88, 179, 223, 194 ], "spans": [ { "bbox": [ 88, 179, 223, 194 ], "type": "text", "content": "1.安装 source insight 软件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 211, 404, 224 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 211, 404, 224 ], "spans": [ { "bbox": [ 110, 211, 404, 224 ], "type": "text", "content": "到网上搜索该软件，可以安装一个 30天免费的版本，如图所示：", "score": 1.0 } ] } ] }, { "bbox": [ 92, 243, 298, 255 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 93, 243, 297, 255 ], "spans": [ { "bbox": [ 93, 243, 297, 255 ], "type": "text", "content": "Source Insight 软件下载 一键安装 360软件宝库", "score": 0.971 } ] } ] }, { "type": "image", "bbox": [ 92, 257, 413, 346 ], "blocks": [ { "bbox": [ 92, 257, 413, 346 ], "lines": [ { "bbox": [ 92, 257, 413, 346 ], "spans": [ { "bbox": [ 92, 257, 413, 346 ], "type": "image", "image_path": "b966210afb24171ff27802ac0d7dcccb8dfacae1774a68c30c774d44891a0078.jpg" } ] } ], "index": 7, "angle": 0, "type": "image_body" } ], "index": 7 }, { "bbox": [ 111, 362, 495, 391 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 113, 361, 495, 376 ], "spans": [ { "bbox": [ 113, 361, 495, 376 ], "type": "text", "content": "当然，也可以在 linux下通过wine 安装 source insight，安装过程可以参考如下资源：", "score": 1.0 } ] }, { "bbox": [ 144, 379, 387, 391 ], "spans": [ { "bbox": [ 144, 379, 387, 391 ], "type": "text", "content": "http://blog.csdn.net/gaojinshan/article/details/9272123", "score": 1.0 } ] } ] }, { "bbox": [ 94, 393, 505, 439 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 113, 394, 505, 407 ], "spans": [ { "bbox": [ 113, 394, 505, 407 ], "type": "text", "content": "注意：wine 安装在当前用户目录下，且是隐藏的，用ls -a可见，也可通过图形界面直", "score": 1.0 } ] }, { "bbox": [ 96, 408, 506, 423 ], "spans": [ { "bbox": [ 96, 408, 506, 423 ], "type": "text", "content": "接看。安装好的 sourceinsight 程序放在 wine/driver_c/Program Files(x86)/下。可直接通过点", "score": 1.0 } ] }, { "bbox": [ 96, 424, 136, 439 ], "spans": [ { "bbox": [ 96, 424, 136, 439 ], "type": "text", "content": "击启动。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 486, 149, 498 ], "type": "title", "angle": 0, "index": 10, "lines": [ { "bbox": [ 87, 485, 149, 499 ], "spans": [ { "bbox": [ 87, 485, 149, 499 ], "type": "text", "content": "2. 新建工程", "score": 1.0 } ] } ] }, { "bbox": [ 108, 517, 377, 545 ], "type": "list", "angle": 0, "index": 13, "blocks": [ { "bbox": [ 108, 517, 224, 528 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 108, 515, 225, 531 ], "spans": [ { "bbox": [ 108, 515, 225, 531 ], "type": "text", "content": "1）运行 source insight", "score": 1.0 } ] } ] }, { "bbox": [ 108, 532, 377, 545 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 532, 379, 546 ], "spans": [ { "bbox": [ 109, 532, 379, 546 ], "type": "text", "content": "2）选择 project->New project 新建一个工程，如图所示：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "type": "image", "bbox": [ 91, 558, 445, 654 ], "blocks": [ { "bbox": [ 91, 558, 445, 654 ], "lines": [ { "bbox": [ 91, 558, 445, 654 ], "spans": [ { "bbox": [ 91, 558, 445, 654 ], "type": "image", "image_path": "4fd6a303cac45caa797714b44e86cae16f19946ef87fc8968666f3d8f52db573.jpg" } ] } ], "index": 14, "angle": 0, "type": "image_body" } ], "index": 14 }, { "bbox": [ 86, 670, 506, 699 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 671, 505, 682 ], "spans": [ { "bbox": [ 110, 671, 505, 682 ], "type": "text", "content": "输入新建工程的名字及工程文件的保存路径，单击“OK”关闭该窗口，将同时打开新建", "score": 1.0 } ] }, { "bbox": [ 89, 687, 230, 698 ], "spans": [ { "bbox": [ 89, 687, 230, 698 ], "type": "text", "content": "工程的设置对话框，如图所示：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 7 }, { "para_blocks": [ { "type": "image", "bbox": [ 91, 75, 508, 426 ], "blocks": [ { "bbox": [ 91, 75, 508, 426 ], "lines": [ { "bbox": [ 91, 75, 508, 426 ], "spans": [ { "bbox": [ 91, 75, 508, 426 ], "type": "image", "image_path": "76fec6db73191d2cb4ff810c24067cf91a461e94816244d23d52715c95a68c81.jpg" } ] } ], "index": 1, "angle": 0, "type": "image_body" } ], "index": 1 }, { "bbox": [ 86, 446, 505, 491 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 446, 505, 460 ], "spans": [ { "bbox": [ 108, 446, 505, 460 ], "type": "text", "content": "3）在上面的设置对话框中，首先设置配置文件，可采用默认设置，也可以选择“Project", "score": 1.0 } ] }, { "bbox": [ 88, 464, 506, 476 ], "spans": [ { "bbox": [ 88, 464, 506, 476 ], "type": "text", "content": "has its own configuration file”；然后选择要添加代码的目录，如本示例设置为 linux", "score": 1.0 } ] }, { "bbox": [ 88, 478, 158, 491 ], "spans": [ { "bbox": [ 88, 478, 158, 491 ], "type": "text", "content": "源码所在目录：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 94, 510, 519, 549 ], "blocks": [ { "bbox": [ 94, 510, 519, 549 ], "lines": [ { "bbox": [ 94, 510, 519, 549 ], "spans": [ { "bbox": [ 94, 510, 519, 549 ], "type": "image", "image_path": "70169cfda03b9cc821a7d21997c442a2997def5df6ac33c7be44da8ac9e6c2f0.jpg" } ] } ], "index": 3, "angle": 0, "type": "image_body" } ], "index": 3 }, { "bbox": [ 108, 568, 440, 581 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 569, 441, 582 ], "spans": [ { "bbox": [ 110, 569, 441, 582 ], "type": "text", "content": "最后单击“OK”关闭该对话框，将打开工程文件加载对话框，如图所示：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 8 }, { "para_blocks": [ { "type": "image", "bbox": [ 91, 78, 507, 300 ], "blocks": [ { "bbox": [ 91, 78, 507, 300 ], "lines": [ { "bbox": [ 91, 78, 507, 300 ], "spans": [ { "bbox": [ 91, 78, 507, 300 ], "type": "image", "image_path": "c393fc5f81f73ab21b845c4e4e345edd9e2f13053e4ed783f4867dbd07e55776.jpg" } ] } ], "index": 1, "angle": 0, "type": "image_body" } ], "index": 1 }, { "bbox": [ 86, 307, 505, 336 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 308, 505, 321 ], "spans": [ { "bbox": [ 110, 308, 505, 321 ], "type": "text", "content": "可直接选择刚才的 linux源码目录，单击“Add Tree”按钮，将递归加入指定目录中所", "score": 1.0 } ] }, { "bbox": [ 89, 324, 243, 336 ], "spans": [ { "bbox": [ 89, 324, 243, 336 ], "type": "text", "content": "有文件到工程中。关闭该对话框。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 339, 285, 351 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 339, 285, 352 ], "spans": [ { "bbox": [ 108, 339, 285, 352 ], "type": "text", "content": "4）“同步”文件或者“重编译”工程", "score": 1.0 } ] } ] }, { "bbox": [ 86, 354, 505, 400 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 355, 502, 368 ], "spans": [ { "bbox": [ 110, 355, 502, 368 ], "type": "text", "content": "这是很重要的一步，将对代码间调用关系等进行内部初始化。推荐大家进行“重新编译”", "score": 1.0 } ] }, { "bbox": [ 89, 372, 505, 384 ], "spans": [ { "bbox": [ 89, 372, 505, 384 ], "type": "text", "content": "工程，这样可以建立一个与路径无关的工程，也就是这个工程拿到哪都可以使用，而同步不", "score": 1.0 } ] }, { "bbox": [ 89, 388, 179, 401 ], "spans": [ { "bbox": [ 89, 388, 179, 401 ], "type": "text", "content": "可以。操作方法是：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 403, 506, 448 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 109, 402, 506, 417 ], "spans": [ { "bbox": [ 109, 402, 506, 417 ], "type": "text", "content": "同步文件：选择 project->synchronize file…，在显示的对话框中你可以选择：Remove", "score": 1.0 } ] }, { "bbox": [ 87, 419, 506, 433 ], "spans": [ { "bbox": [ 87, 419, 506, 433 ], "type": "text", "content": "missing files from projcet 和 Suppress warning messages,或者再加上 Force all files", "score": 1.0 } ] }, { "bbox": [ 88, 434, 437, 448 ], "spans": [ { "bbox": [ 88, 434, 437, 448 ], "type": "text", "content": "to be re-parsed，然后单击“OK”，之后工程中的源码就可以进行关联了。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 450, 500, 480 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 450, 499, 465 ], "spans": [ { "bbox": [ 110, 450, 499, 465 ], "type": "text", "content": "重编译工程：选择 project->rebuild project… ，在显示的对话框中，只选择第三项：", "score": 1.0 } ] }, { "bbox": [ 88, 467, 426, 480 ], "spans": [ { "bbox": [ 88, 467, 426, 480 ], "type": "text", "content": "Re-Create the whole project from scratch,然后单击“OK”就可以了。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 495, 243, 508 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 88, 495, 244, 509 ], "spans": [ { "bbox": [ 88, 495, 244, 509 ], "type": "text", "content": "3.使用 sought insight 查看源码", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 9 }, { "para_blocks": [ { "bbox": [ 86, 76, 496, 105 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 74, 498, 90 ], "spans": [ { "bbox": [ 109, 74, 498, 90 ], "type": "text", "content": "启动 soughtinsight，选择 project->Open Project…打开工程，如前面建立的 test", "score": 1.0 } ] }, { "bbox": [ 89, 94, 273, 106 ], "spans": [ { "bbox": [ 89, 94, 273, 106 ], "type": "text", "content": "工程，默认是打开三个窗口，如图所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 89, 110, 508, 321 ], "blocks": [ { "bbox": [ 89, 110, 508, 321 ], "lines": [ { "bbox": [ 89, 110, 508, 321 ], "spans": [ { "bbox": [ 89, 110, 508, 321 ], "type": "image", "image_path": "42513e383a540bb5e6386f3178deb44d628f914b827c28b5f933adcf355969f2.jpg" } ] } ], "index": 2, "angle": 0, "type": "image_body" } ], "index": 2 }, { "bbox": [ 113, 341, 214, 354 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 115, 342, 215, 354 ], "spans": [ { "bbox": [ 115, 342, 215, 354 ], "type": "text", "content": "（1）查看函数及变量：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 357, 505, 417 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 357, 505, 370 ], "spans": [ { "bbox": [ 109, 357, 505, 370 ], "type": "text", "content": "在“工程窗口”中选择并双击一个要查看的文件，将在“文件窗口”显示该文件的所有", "score": 1.0 } ] }, { "bbox": [ 89, 374, 500, 386 ], "spans": [ { "bbox": [ 89, 374, 500, 386 ], "type": "text", "content": "内容：包含的头文件、定义的变量、函数（包括函数中的变量定义、所调用的其他函数等），", "score": 1.0 } ] }, { "bbox": [ 89, 389, 506, 401 ], "spans": [ { "bbox": [ 89, 389, 506, 401 ], "type": "text", "content": "在其中选择一个函数（或变量）并单击，将在“内容窗口”中显示该函数（或变量）的详细", "score": 1.0 } ] }, { "bbox": [ 89, 405, 168, 417 ], "spans": [ { "bbox": [ 89, 405, 168, 417 ], "type": "text", "content": "定义，如图所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 89, 437, 508, 613 ], "blocks": [ { "bbox": [ 89, 437, 508, 613 ], "lines": [ { "bbox": [ 89, 437, 508, 613 ], "spans": [ { "bbox": [ 89, 437, 508, 613 ], "type": "image", "image_path": "fb4b40848430dc9246725c30e9d9e4a5c647bc258b41a1faf38ec74a3418c551.jpg" } ] } ], "index": 5, "angle": 0, "type": "image_body" } ], "index": 5 }, { "bbox": [ 86, 636, 504, 665 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 636, 505, 649 ], "spans": [ { "bbox": [ 110, 636, 505, 649 ], "type": "text", "content": "此时如果再单击工具栏上的“relation window”，将显示所有调用该函数的位置，如", "score": 1.0 } ] }, { "bbox": [ 89, 652, 189, 665 ], "spans": [ { "bbox": [ 89, 652, 189, 665 ], "type": "text", "content": "图中右下角窗口所示：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 10 }, { "para_blocks": [ { "type": "image", "bbox": [ 89, 74, 509, 303 ], "blocks": [ { "bbox": [ 89, 74, 509, 303 ], "lines": [ { "bbox": [ 89, 74, 509, 303 ], "spans": [ { "bbox": [ 89, 74, 509, 303 ], "type": "image", "image_path": "521fa64fb51d96ca6e8768cc65be06fae4fb3793b285609fbe993befd385f756.jpg" } ] } ], "index": 1, "angle": 0, "type": "image_body" } ], "index": 1 }, { "bbox": [ 113, 322, 190, 334 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 322, 190, 335 ], "spans": [ { "bbox": [ 114, 322, 190, 335 ], "type": "text", "content": "（2）搜索字符串", "score": 1.0 } ] } ] }, { "bbox": [ 86, 337, 505, 366 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 337, 505, 351 ], "spans": [ { "bbox": [ 110, 337, 505, 351 ], "type": "text", "content": "单击工具栏上的“R”按钮，将显示字符串查找窗口“Lookup References”，其中查找", "score": 1.0 } ] }, { "bbox": [ 89, 354, 298, 364 ], "spans": [ { "bbox": [ 89, 354, 298, 364 ], "type": "text", "content": "选项“Options”按如图设置即可，如图所示：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 370, 223, 382 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 115, 370, 221, 381 ], "spans": [ { "bbox": [ 115, 370, 221, 381 ], "type": "text", "content": "（3）使用鼠标右键功能", "score": 1.0 } ] } ] }, { "bbox": [ 86, 385, 505, 414 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 386, 505, 398 ], "spans": [ { "bbox": [ 110, 386, 505, 398 ], "type": "text", "content": "在source insight中，对任何文件、函数或者变量点击鼠标右键，会显示一个快捷菜", "score": 1.0 } ] }, { "bbox": [ 89, 401, 389, 413 ], "spans": [ { "bbox": [ 89, 401, 389, 413 ], "type": "text", "content": "单，能更加方便的实现跳转功能，请大家参考其他相关资料学习。", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 88, 418, 459, 645 ], "blocks": [ { "bbox": [ 88, 418, 459, 645 ], "lines": [ { "bbox": [ 88, 418, 459, 645 ], "spans": [ { "bbox": [ 88, 418, 459, 645 ], "type": "image", "image_path": "944d196d99288cc023949a198d0b741ab2b900b3642b9ea4fab3e55e37f8da63.jpg" } ] } ], "index": 6, "angle": 0, "type": "image_body" } ], "index": 6 }, { "bbox": [ 108, 650, 415, 664 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 650, 415, 666 ], "spans": [ { "bbox": [ 109, 650, 415, 666 ], "type": "text", "content": "如查找“effective_prio”,单击“Search”后显示结果如图所示：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 11 }, { "para_blocks": [ { "type": "image", "bbox": [ 88, 73, 508, 180 ], "blocks": [ { "bbox": [ 88, 73, 508, 180 ], "lines": [ { "bbox": [ 88, 73, 508, 180 ], "spans": [ { "bbox": [ 88, 73, 508, 180 ], "type": "image", "image_path": "bc6e2c47242f2e9fca0219e263bef1d2411166f22d5e435e0f14c52b3a5e8680.jpg" } ] } ], "index": 1, "angle": 0, "type": "image_body" } ], "index": 1 }, { "bbox": [ 86, 196, 505, 226 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 197, 505, 210 ], "spans": [ { "bbox": [ 110, 197, 505, 210 ], "type": "text", "content": "点击左边或工具栏中的红色小按钮就可以展开内容，其中工具栏中的按钮下面还有一个", "score": 1.0 } ] }, { "bbox": [ 89, 213, 484, 226 ], "spans": [ { "bbox": [ 89, 213, 484, 226 ], "type": "text", "content": "红色的“向左箭头”和“向右箭头”，标明一个向前，一个向后依次打开，非常方便。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 248, 269, 264 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 116, 247, 269, 264 ], "spans": [ { "bbox": [ 116, 247, 269, 264 ], "type": "text", "content": "6.2 linux 中的汇编语言", "score": 1.0 } ] } ] }, { "bbox": [ 86, 287, 505, 333 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 288, 505, 301 ], "spans": [ { "bbox": [ 110, 288, 505, 301 ], "type": "text", "content": "虽然Linux内核的绝大部分代码是用 C 语言编写的，但仍然不可避免地在某些关键地", "score": 1.0 } ] }, { "bbox": [ 88, 303, 505, 317 ], "spans": [ { "bbox": [ 88, 303, 505, 317 ], "type": "text", "content": "方使用了汇编代码，其中主要是在 Linux 的启动部分。Linux主要使用AT&T汇编语言，它", "score": 1.0 } ] }, { "bbox": [ 89, 320, 499, 333 ], "spans": [ { "bbox": [ 89, 320, 499, 333 ], "type": "text", "content": "与intel汇编大同小异，为方便大家阅读源码，下面简单介绍 AT&T汇编的一些基本知识。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 351, 283, 364 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 88, 352, 283, 364 ], "spans": [ { "bbox": [ 88, 352, 283, 364 ], "type": "text", "content": "6.2.1 AT&T 与 intel 汇编的语法格式比较", "score": 1.0 } ] } ] }, { "bbox": [ 105, 382, 232, 395 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 107, 383, 232, 396 ], "spans": [ { "bbox": [ 107, 383, 232, 396 ], "type": "text", "content": "1. 寄存器及立即数的前缀", "score": 1.0 } ] } ] }, { "bbox": [ 86, 412, 505, 441 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 412, 506, 426 ], "spans": [ { "bbox": [ 109, 412, 506, 426 ], "type": "text", "content": "在 AT&T 汇编格式中，寄存器名前要冠以 “%”，立即数前要冠以“$”；而在 Intel 汇", "score": 1.0 } ] }, { "bbox": [ 89, 428, 336, 441 ], "spans": [ { "bbox": [ 89, 428, 336, 441 ], "type": "text", "content": "编格式中，寄存器名及立即数都不需要加前缀。例如：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 122, 442, 424, 510 ], "blocks": [ { "bbox": [ 122, 442, 424, 510 ], "lines": [ { "bbox": [ 122, 442, 424, 510 ], "spans": [ { "bbox": [ 122, 442, 424, 510 ], "type": "table", "html": "
AT&T 格式Intel 格式
pushl %eaxpush eax
pushl $1push 1
", "image_path": "dea4555304cbce1723f54c3c6fb58b97f6419d4640b30a694c9dd9edd2a82838.jpg" } ] } ], "index": 8, "angle": 0, "type": "table_body" } ], "index": 8 }, { "bbox": [ 105, 528, 189, 541 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 105, 528, 190, 541 ], "spans": [ { "bbox": [ 105, 528, 190, 541 ], "type": "text", "content": "2. 操作数的方向", "score": 1.0 } ] } ] }, { "bbox": [ 86, 558, 505, 601 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 559, 505, 570 ], "spans": [ { "bbox": [ 110, 559, 505, 570 ], "type": "text", "content": "AT&T 和 Intel 格式中的源操作数和目标操作数的位置正好相反。在 Intel 汇编格式", "score": 1.0 } ] }, { "bbox": [ 89, 575, 500, 586 ], "spans": [ { "bbox": [ 89, 575, 500, 586 ], "type": "text", "content": "中，目标操作数在源操作数的左边；而在 AT&T 汇编格式中，目标操作数在源操作数的右边。", "score": 1.0 } ] }, { "bbox": [ 88, 588, 117, 604 ], "spans": [ { "bbox": [ 88, 588, 117, 604 ], "type": "text", "content": "例如：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 121, 603, 424, 649 ], "blocks": [ { "bbox": [ 121, 603, 424, 649 ], "lines": [ { "bbox": [ 121, 603, 424, 649 ], "spans": [ { "bbox": [ 121, 603, 424, 649 ], "type": "table", "html": "
AT&T 格式Intel 格式
add1 $1, %eaxadd eax, 1
", "image_path": "d34f4a1407f7e75fadb3952c3810975428d129585c23c4d7a291b48c57124364.jpg" } ] } ], "index": 11, "angle": 0, "type": "table_body" } ], "index": 11 }, { "bbox": [ 105, 666, 190, 680 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 105, 667, 189, 680 ], "spans": [ { "bbox": [ 105, 667, 189, 680 ], "type": "text", "content": "3. 操作数的字长", "score": 1.0 } ] } ] }, { "bbox": [ 86, 697, 502, 756 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 697, 503, 709 ], "spans": [ { "bbox": [ 109, 697, 503, 709 ], "type": "text", "content": "在 AT&T 汇编格式中，操作数的字长由操作符的最后一个字母决定，后缀'b'、'w'、'l", "score": 1.0 } ] }, { "bbox": [ 89, 714, 500, 726 ], "spans": [ { "bbox": [ 89, 714, 500, 726 ], "type": "text", "content": "分别表示操作数为字节（byte，8 比特）、字（word，16 比特）和长字（long，32 比特）；", "score": 1.0 } ] }, { "bbox": [ 89, 729, 500, 741 ], "spans": [ { "bbox": [ 89, 729, 500, 741 ], "type": "text", "content": "而在 Intel 汇编格式中，操作数的字长是用 \"byte ptr\" 和 \"word ptr\" 等前缀来表示的。", "score": 1.0 } ] }, { "bbox": [ 88, 743, 117, 759 ], "spans": [ { "bbox": [ 88, 743, 117, 759 ], "type": "text", "content": "例如：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 12 }, { "para_blocks": [ { "type": "table", "bbox": [ 121, 71, 424, 118 ], "blocks": [ { "bbox": [ 121, 71, 424, 118 ], "lines": [ { "bbox": [ 121, 71, 424, 118 ], "spans": [ { "bbox": [ 121, 71, 424, 118 ], "type": "table", "html": "
AT&T 格式Intel 格式
movb val, %a1mov al, byte ptr val
", "image_path": "1f4bb0efe3b9d9fc24f6bdb32f596e5d6c8697dfa185231ee792620a94782180.jpg" } ] } ], "index": 1, "angle": 0, "type": "table_body" } ], "index": 1 }, { "bbox": [ 105, 135, 240, 149 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 105, 134, 240, 150 ], "spans": [ { "bbox": [ 105, 134, 240, 150 ], "type": "text", "content": "4. Jump 和 call 指令的前缀", "score": 1.0 } ] } ] }, { "bbox": [ 86, 164, 504, 195 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 165, 505, 178 ], "spans": [ { "bbox": [ 109, 165, 505, 178 ], "type": "text", "content": "在 AT&T 汇编格式中，绝对转移和调用指令（jump/call）的操作数前要加上'*'作为前", "score": 1.0 } ] }, { "bbox": [ 89, 182, 248, 193 ], "spans": [ { "bbox": [ 89, 182, 248, 193 ], "type": "text", "content": "缀，而在 Intel 格式中则不需要。", "score": 1.0 } ] } ] }, { "bbox": [ 105, 212, 201, 227 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 105, 212, 200, 227 ], "spans": [ { "bbox": [ 105, 212, 200, 227 ], "type": "text", "content": "5. 内存单元操作数", "score": 1.0 } ] } ] }, { "bbox": [ 86, 243, 505, 270 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 243, 505, 255 ], "spans": [ { "bbox": [ 110, 243, 505, 255 ], "type": "text", "content": "内存单元操作数的寻址方式是间接寻址。在 AT&T 汇编格式中，基址寄存器用（）括起", "score": 1.0 } ] }, { "bbox": [ 89, 259, 252, 271 ], "spans": [ { "bbox": [ 89, 259, 252, 271 ], "type": "text", "content": "来，而Intel中用[]括起来。例如：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 121, 272, 424, 341 ], "blocks": [ { "bbox": [ 121, 272, 424, 341 ], "lines": [ { "bbox": [ 121, 272, 424, 341 ], "spans": [ { "bbox": [ 121, 272, 424, 341 ], "type": "table", "html": "
AT&T 格式Intel 格式
movl -4(%ebp), %eaxmov eax, [ebp - 4]
movl 5(%ebx),%eaxmov eax, [ebx+5]
", "image_path": "9bbd2ad3da6ffe9a463e5a1b789c89043941b21c83e8976dfc904f8e0fceb0e1.jpg" } ] } ], "index": 6, "angle": 0, "type": "table_body" } ], "index": 6 }, { "bbox": [ 86, 358, 193, 371 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 88, 357, 193, 372 ], "spans": [ { "bbox": [ 88, 357, 193, 372 ], "type": "text", "content": "6.2.2 Gcc 嵌入式汇编", "score": 1.0 } ] } ] }, { "bbox": [ 86, 387, 505, 433 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 389, 505, 400 ], "spans": [ { "bbox": [ 109, 389, 505, 400 ], "type": "text", "content": "Linux 下用汇编语言编写的代码具有两种不同的形式。第一种是整个程序全部用汇编语", "score": 1.0 } ] }, { "bbox": [ 89, 404, 505, 417 ], "spans": [ { "bbox": [ 89, 404, 505, 417 ], "type": "text", "content": "言编写；第二种是内嵌的汇编代码，指嵌入到C 语言程序中的汇编代码片段。下面介绍gcc", "score": 1.0 } ] }, { "bbox": [ 89, 420, 200, 433 ], "spans": [ { "bbox": [ 89, 420, 200, 433 ], "type": "text", "content": "嵌入式汇编的相关知识。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 451, 235, 464 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 110, 451, 235, 465 ], "spans": [ { "bbox": [ 110, 451, 235, 465 ], "type": "text", "content": "1. 嵌入式汇编的一般形式", "score": 1.0 } ] } ] }, { "bbox": [ 108, 481, 368, 494 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 119, 480, 370, 495 ], "spans": [ { "bbox": [ 119, 483, 139, 494 ], "type": "text", "content": "asm", "score": 1.0 }, { "bbox": [ 148, 481, 308, 495 ], "type": "text", "content": "__volatile__(\"asm statements\"", "score": 1.0 }, { "bbox": [ 324, 480, 370, 495 ], "type": "text", "content": "//指令部", "score": 1.0 } ] } ] }, { "bbox": [ 110, 497, 279, 510 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 108, 497, 280, 512 ], "spans": [ { "bbox": [ 108, 497, 280, 512 ], "type": "text", "content": ": outputs （optional） //输出部", "score": 1.0 } ] } ] }, { "bbox": [ 110, 513, 274, 526 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 512, 276, 528 ], "spans": [ { "bbox": [ 108, 512, 276, 528 ], "type": "text", "content": ": inputs （optional） //输入部", "score": 1.0 } ] } ] }, { "bbox": [ 110, 529, 279, 541 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 528, 280, 543 ], "spans": [ { "bbox": [ 109, 528, 280, 543 ], "type": "text", "content": ": modified （optional） //修改部", "score": 1.0 } ] } ] }, { "bbox": [ 109, 545, 120, 556 ], "type": "text", "angle": 0, "index": 14, "lines": [] }, { "bbox": [ 108, 560, 293, 573 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 111, 561, 294, 574 ], "spans": [ { "bbox": [ 111, 561, 294, 574 ], "type": "text", "content": "下面对语句格式的各部分分别进行说明：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 577, 174, 589 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 113, 575, 169, 592 ], "spans": [ { "bbox": [ 113, 575, 169, 592 ], "type": "text", "content": "（1）__asm_", "score": 1.0 } ] } ] }, { "bbox": [ 108, 592, 383, 605 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 110, 592, 384, 606 ], "spans": [ { "bbox": [ 110, 592, 384, 606 ], "type": "text", "content": "表示汇编代码的开始，也可以写成“asm”，两者完全相同。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 608, 201, 621 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 113, 605, 200, 624 ], "spans": [ { "bbox": [ 113, 605, 200, 624 ], "type": "text", "content": "（2）__volatile__", "score": 1.0 } ] } ] }, { "bbox": [ 107, 624, 483, 636 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 624, 484, 637 ], "spans": [ { "bbox": [ 109, 624, 484, 637 ], "type": "text", "content": "这是一个可选项，它告诉编译器不要优化该汇编语句，主要用于硬件级程序设计。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 640, 263, 652 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 114, 639, 263, 654 ], "spans": [ { "bbox": [ 114, 639, 263, 654 ], "type": "text", "content": "（3）指令部：\"asm statements\"", "score": 1.0 } ] } ] }, { "bbox": [ 86, 655, 500, 684 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 110, 656, 501, 669 ], "spans": [ { "bbox": [ 110, 656, 501, 669 ], "type": "text", "content": "是汇编指令部分，可以是一条或多条指令。如果是多条指令，则指令间需要使用“\\n\\t”", "score": 1.0 } ] }, { "bbox": [ 88, 671, 138, 685 ], "spans": [ { "bbox": [ 88, 671, 138, 685 ], "type": "text", "content": "进行分隔。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 687, 296, 701 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 109, 687, 296, 702 ], "spans": [ { "bbox": [ 109, 687, 296, 702 ], "type": "text", "content": "如读 CR0 寄存器的 read_cr0()的定义为：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 703, 330, 716 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 109, 703, 330, 718 ], "spans": [ { "bbox": [ 109, 703, 330, 718 ], "type": "text", "content": "static inline unsigned long read_cr0(void)", "score": 1.0 } ] } ] }, { "bbox": [ 110, 719, 119, 731 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 108, 720, 119, 733 ], "spans": [ { "bbox": [ 108, 720, 119, 733 ], "type": "text", "content": "{", "score": 1.0 } ] } ] }, { "bbox": [ 139, 735, 374, 748 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 140, 735, 375, 749 ], "spans": [ { "bbox": [ 140, 735, 375, 749 ], "type": "text", "content": "unsigned long cr0; //汇编内部定义的局部变量", "score": 1.0 } ] } ] }, { "bbox": [ 139, 751, 468, 765 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 139, 750, 470, 766 ], "spans": [ { "bbox": [ 139, 750, 271, 766 ], "type": "text", "content": "asm volatile(\"movq %%cr0,", "score": 1.0 }, { "bbox": [ 271, 751, 289, 764 ], "type": "inline_equation", "content": "\\% 0 ^ { \\prime \\prime }", "score": 0.5 }, { "bbox": [ 290, 750, 302, 766 ], "type": "text", "content": ":", "score": 1.0 }, { "bbox": [ 302, 751, 327, 764 ], "type": "inline_equation", "content": "\\prime \\prime = \\mathrm { r } ^ { \\prime \\prime }", "score": 0.74 }, { "bbox": [ 327, 750, 470, 766 ], "type": "text", "content": "(cr0)); // 嵌入式汇编语句", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 13 }, { "para_blocks": [ { "type": "code", "bbox": [ 108, 74, 199, 102 ], "blocks": [ { "bbox": [ 108, 74, 199, 102 ], "lines": [ { "bbox": [ 108, 74, 199, 102 ], "spans": [ { "bbox": [ 108, 74, 199, 102 ], "type": "text", "content": "return cr0;" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "lua" }, { "bbox": [ 86, 105, 511, 184 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 106, 509, 117 ], "spans": [ { "bbox": [ 110, 106, 509, 117 ], "type": "text", "content": "使用嵌入式汇编时，汇编语句中的操作数如何与 C 代码中的变量相结合是个很大的问题。", "score": 1.0 } ] }, { "bbox": [ 89, 122, 502, 133 ], "spans": [ { "bbox": [ 89, 122, 502, 133 ], "type": "text", "content": "GCC的解决方法是：需要使用指定寄存器的值时，寄存器名前面应该加上两个'%'，如示例", "score": 1.0 } ] }, { "bbox": [ 89, 137, 506, 150 ], "spans": [ { "bbox": [ 89, 137, 199, 150 ], "type": "text", "content": "中的“%%cr0”表示使用", "score": 1.0 }, { "bbox": [ 199, 137, 217, 150 ], "type": "inline_equation", "content": "\\mathrm { c r 0 }", "score": 0.73 }, { "bbox": [ 218, 137, 506, 150 ], "type": "text", "content": "寄存器；需要使用C代码中的变量时，采用加上前缀“%”的数", "score": 1.0 } ] }, { "bbox": [ 89, 154, 505, 165 ], "spans": [ { "bbox": [ 89, 154, 505, 165 ], "type": "text", "content": "字(如%0，%1)来表示，其中数字是从输出部的第一个约束开始从 0依次编号。如示例汇编语", "score": 1.0 } ] }, { "bbox": [ 88, 169, 310, 182 ], "spans": [ { "bbox": [ 88, 169, 310, 182 ], "type": "text", "content": "句中的操作数“%0”对应输出部的“cr0”变量。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 200, 290, 214 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 114, 200, 290, 216 ], "spans": [ { "bbox": [ 114, 200, 290, 216 ], "type": "text", "content": "（4）输出部：: outputs （optional）", "score": 1.0 } ] } ] }, { "bbox": [ 86, 216, 506, 262 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 218, 505, 229 ], "spans": [ { "bbox": [ 110, 218, 505, 229 ], "type": "text", "content": "输出部分用于规定输出变量（目标操作数）如何与汇编语句中的操作数相结合的约束条", "score": 1.0 } ] }, { "bbox": [ 89, 232, 504, 244 ], "spans": [ { "bbox": [ 89, 232, 318, 244 ], "type": "text", "content": "件，可以有多个约束，以逗号分开。每个约束以“", "score": 1.0 }, { "bbox": [ 319, 232, 333, 243 ], "type": "inline_equation", "content": "= ^ { \\mathfrak { p } }", "score": 0.52 }, { "bbox": [ 333, 232, 504, 244 ], "type": "text", "content": "开头（表示只用输出），接着用一个", "score": 1.0 } ] }, { "bbox": [ 89, 248, 348, 261 ], "spans": [ { "bbox": [ 89, 248, 348, 261 ], "type": "text", "content": "字母来表示操作数的类型，最后用“（）”说明变量名。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 264, 168, 277 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 109, 264, 168, 278 ], "spans": [ { "bbox": [ 109, 264, 168, 278 ], "type": "text", "content": "如上例中的：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 130, 280, 193, 293 ], "blocks": [ { "bbox": [ 130, 280, 193, 293 ], "lines": [ { "bbox": [ 130, 280, 193, 293 ], "spans": [ { "bbox": [ 130, 280, 193, 293 ], "type": "text", "content": "： " }, { "bbox": [ 130, 280, 193, 293 ], "type": "inline_equation", "content": "\\mathbf{\\Pi}^{\\prime \\prime} = \\mathbf{r}^{\\prime \\prime}" }, { "bbox": [ 130, 280, 193, 293 ], "type": "text", "content": " (cr0)" } ] } ], "index": 6, "angle": 0, "type": "code_body" } ], "index": 6, "sub_type": "algorithm" }, { "bbox": [ 86, 296, 500, 325 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 134, 295, 499, 310 ], "spans": [ { "bbox": [ 134, 295, 139, 310 ], "type": "text", "content": "“", "score": 1.0 }, { "bbox": [ 139, 296, 159, 308 ], "type": "inline_equation", "content": "\\mathit { \\Omega } ^ { \\prime } = \\mathrm { { r } } ^ { \\prime \\prime }", "score": 0.72 }, { "bbox": [ 159, 295, 499, 310 ], "type": "text", "content": "表示相应的目标操作数（指令部分的“%0”）可以使用任何一个通用寄存器；", "score": 1.0 } ] }, { "bbox": [ 89, 312, 253, 325 ], "spans": [ { "bbox": [ 89, 312, 132, 325 ], "type": "text", "content": "并且变量", "score": 1.0 }, { "bbox": [ 133, 312, 151, 324 ], "type": "inline_equation", "content": "\\mathrm { c r 0 }", "score": 0.6 }, { "bbox": [ 151, 312, 253, 325 ], "type": "text", "content": "存放在这个寄存器中。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 327, 351, 341 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 327, 352, 342 ], "spans": [ { "bbox": [ 109, 327, 352, 342 ], "type": "text", "content": "实际上，除“=”外，还有其他保留字，相关含义是：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 137, 341, 467, 409 ], "blocks": [ { "bbox": [ 137, 341, 467, 409 ], "lines": [ { "bbox": [ 137, 341, 467, 409 ], "spans": [ { "bbox": [ 137, 341, 467, 409 ], "type": "table", "html": "
保留字含义
=只写/输出变量
+可读可写变量
&该输出操作数不能使用输入操作数相同的寄存器
", "image_path": "e33a4d7802d2fb176ad08d6c1657f7ab7a09e0d6d4f2bab3d0be4fad18ef3d14.jpg" } ] } ], "index": 9, "angle": 0, "type": "table_body" } ], "index": 9 }, { "bbox": [ 108, 426, 324, 439 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 111, 426, 325, 439 ], "spans": [ { "bbox": [ 111, 426, 325, 439 ], "type": "text", "content": "下表中列举了x86 中最常用的约束字母及含义：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 109, 439, 467, 572 ], "blocks": [ { "bbox": [ 109, 439, 467, 572 ], "lines": [ { "bbox": [ 109, 439, 467, 572 ], "spans": [ { "bbox": [ 109, 439, 467, 572 ], "type": "table", "html": "
约束字母含义
m, v, o表示内存单元
r任意通用寄存器
q寄存器EAX/EBX/ECX/EDX之一
a, b, c, d表示寄存器EAX/EBX/ECX/EDX
S, D寄存器ESI或EDI
A与a+b相同，使用EAX与EBX联合，形成一个64位寄存器
I常数0-31
", "image_path": "4fe52aecfae56fa250b6cccc25919b7ee34765984b0626b6a0612cf285479a5a.jpg" } ] } ], "index": 11, "angle": 0, "type": "table_body" } ], "index": 11 }, { "bbox": [ 113, 589, 284, 602 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 588, 286, 604 ], "spans": [ { "bbox": [ 114, 588, 286, 604 ], "type": "text", "content": "（5）输入部：: inputs （optional）", "score": 1.0 } ] } ] }, { "bbox": [ 86, 605, 505, 697 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 605, 499, 618 ], "spans": [ { "bbox": [ 109, 605, 499, 618 ], "type": "text", "content": "输入约束格式与输出约束相似，但是没有“=”号。如果一个输入约束要求使用寄存器，", "score": 1.0 } ] }, { "bbox": [ 89, 622, 505, 633 ], "spans": [ { "bbox": [ 89, 622, 505, 633 ], "type": "text", "content": "则GCC在预处理时就会为之分配一个寄存器，并插入必要的指令将操作数装入该寄存器。如", "score": 1.0 } ] }, { "bbox": [ 90, 639, 499, 650 ], "spans": [ { "bbox": [ 90, 639, 499, 650 ], "type": "text", "content": "果输入部某个操作数所要求使用的寄存器与前面输出部某个操作数所要求的是同一个寄存", "score": 1.0 } ] }, { "bbox": [ 89, 653, 505, 666 ], "spans": [ { "bbox": [ 89, 653, 505, 666 ], "type": "text", "content": "器，就把输出部对应操作数的编号（如“0”、“1”等）放在输入部中相应位置，但在输入", "score": 1.0 } ] }, { "bbox": [ 89, 669, 505, 682 ], "spans": [ { "bbox": [ 89, 669, 505, 682 ], "type": "text", "content": "部中的参数编号需要另外从新编号。程序样例见后面“linux源码中嵌入式汇编举例”中的", "score": 1.0 } ] }, { "bbox": [ 88, 686, 174, 697 ], "spans": [ { "bbox": [ 88, 686, 174, 697 ], "type": "text", "content": "switch_to()函数。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 700, 348, 714 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 114, 699, 348, 715 ], "spans": [ { "bbox": [ 114, 699, 348, 715 ], "type": "text", "content": "（6）修改部：: registers_modified （optional）", "score": 1.0 } ] } ] }, { "bbox": [ 86, 714, 506, 743 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 716, 504, 727 ], "spans": [ { "bbox": [ 110, 716, 504, 727 ], "type": "text", "content": "汇编语句在执行过程中可能会修改某些寄存器或者内存单元的值，在这里进行列出。一", "score": 1.0 } ] }, { "bbox": [ 89, 730, 298, 743 ], "spans": [ { "bbox": [ 89, 730, 298, 743 ], "type": "text", "content": "般是\"memory\",表示内存发现变化：:\"memory\"", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 14 }, { "para_blocks": [ { "bbox": [ 86, 72, 502, 100 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 114, 72, 502, 86 ], "spans": [ { "bbox": [ 114, 72, 502, 86 ], "type": "text", "content": "此外还有 cc,表示改变条件代码寄存器(condition code register),或者某个寄存", "score": 1.0 } ] }, { "bbox": [ 88, 88, 139, 102 ], "spans": [ { "bbox": [ 88, 88, 139, 102 ], "type": "text", "content": "器名字等。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 105, 505, 149 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 105, 505, 117 ], "spans": [ { "bbox": [ 109, 105, 505, 117 ], "type": "text", "content": "需要说明的是，上述各部分中，指令部是必须的，输入部、输出部及修改部是可选的，", "score": 1.0 } ] }, { "bbox": [ 89, 121, 505, 134 ], "spans": [ { "bbox": [ 89, 121, 505, 134 ], "type": "text", "content": "当输入部存在，而输出部不存在时，冒号“:”要保留；当修改部存在时，三个冒号都要保", "score": 1.0 } ] }, { "bbox": [ 89, 137, 195, 150 ], "spans": [ { "bbox": [ 89, 137, 195, 150 ], "type": "text", "content": "留。如宏定义__cli()：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 107, 153, 429, 166 ], "blocks": [ { "bbox": [ 107, 153, 429, 166 ], "lines": [ { "bbox": [ 107, 153, 429, 166 ], "spans": [ { "bbox": [ 107, 153, 429, 166 ], "type": "text", "content": "define __cli() __asm__ __volatile__( \"cli\": : : \"memory\")" } ] } ], "index": 3, "angle": 0, "type": "code_body" } ], "index": 3, "sub_type": "code", "guess_lang": "yaml" }, { "bbox": [ 86, 168, 505, 196 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 169, 505, 182 ], "spans": [ { "bbox": [ 110, 169, 505, 182 ], "type": "text", "content": "下面是一个简单的嵌入式汇编程序，其功能是将变量 a 的值赋予变量 b，请大家自行分", "score": 1.0 } ] }, { "bbox": [ 86, 182, 107, 200 ], "spans": [ { "bbox": [ 86, 182, 107, 200 ], "type": "text", "content": "析：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 107, 200, 380, 372 ], "blocks": [ { "bbox": [ 107, 200, 380, 372 ], "lines": [ { "bbox": [ 107, 200, 380, 372 ], "spans": [ { "bbox": [ 107, 200, 380, 372 ], "type": "text", "content": "/\\*Embedded.c\\*/ \nint main() \n{ int " }, { "bbox": [ 107, 200, 380, 372 ], "type": "inline_equation", "content": "\\mathrm{a} = 10" }, { "bbox": [ 107, 200, 380, 372 ], "type": "text", "content": " ， " }, { "bbox": [ 107, 200, 380, 372 ], "type": "inline_equation", "content": "\\mathrm{b} = 0" }, { "bbox": [ 107, 200, 380, 372 ], "type": "text", "content": " ： _asm_ volatile_(\"movl %1,%%eax;\\\\n\\\\r\" \"movl%%eax， " }, { "bbox": [ 107, 200, 380, 372 ], "type": "inline_equation", "content": "\\% 0" }, { "bbox": [ 107, 200, 380, 372 ], "type": "text", "content": " ： " }, { "bbox": [ 107, 200, 380, 372 ], "type": "inline_equation", "content": "^{\\prime \\prime} = \\mathrm{r}^{\\prime \\prime}(\\mathrm{b})" }, { "bbox": [ 107, 200, 380, 372 ], "type": "text", "content": " /\\*输出部\\*/ :\"\\r\"(a) /\\*输入部\\*/ :\"\\%eax\"); /\\*修改部\\*/ printf(\"Result:%d,%d\\\\n\",a,b); \n}" } ] } ], "index": 5, "angle": 0, "type": "code_body" } ], "index": 5, "sub_type": "algorithm" }, { "bbox": [ 108, 390, 263, 403 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 108, 391, 264, 405 ], "spans": [ { "bbox": [ 108, 391, 264, 405 ], "type": "text", "content": "2. Linux 源码中嵌入式汇编举例", "score": 1.0 } ] } ] }, { "bbox": [ 113, 420, 183, 433 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 420, 185, 433 ], "spans": [ { "bbox": [ 114, 420, 185, 433 ], "type": "text", "content": "（1）简单应用：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 436, 473, 497 ], "blocks": [ { "bbox": [ 108, 436, 473, 497 ], "lines": [ { "bbox": [ 108, 436, 473, 497 ], "spans": [ { "bbox": [ 108, 436, 473, 497 ], "type": "text", "content": "define __save_flags(x) \\ \nasm volatile (\"stc ccr, %w0\": \"=r\" (x)) //将 flags 值压栈 \n#define __restore_flags(x) \\ \nasm volatile (\"ldc %w0, ccr\": \"r\" (x)) //恢复 flags 值到 cpu 中" } ] } ], "index": 8, "angle": 0, "type": "code_body" } ], "index": 8, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 113, 500, 183, 513 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 500, 185, 513 ], "spans": [ { "bbox": [ 114, 500, 185, 513 ], "type": "text", "content": "（2）复杂应用：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 515, 500, 752 ], "blocks": [ { "bbox": [ 108, 515, 500, 752 ], "lines": [ { "bbox": [ 108, 515, 500, 752 ], "spans": [ { "bbox": [ 108, 515, 500, 752 ], "type": "text", "content": "static inline int strcmp(const char *cs, const char *ct) \n{ \n char res; \n asm(\"\\n\") \n \"1: move.b (%0)+,%2\\n\" /* get *cs */ \n \" cmp.b (%1)+,%2\\n\" /* compare a byte */ \n \" jne 2f\\n\" /* not equal, break out */ \n \" tst.b %2\\n\" /* at end of cs? */ \n \" jne 1b\\n\" /* no, keep going */ \n \" jra 3f\\n\" /* strings are equal */ \n \"2: sub.b -(%1),%2\\n\" /* *cs - *ct */ \n \"3:\" \n : \"+\" (cs), \"+\" (ct), \"=\" (res)); \n return res;" } ] } ], "index": 10, "angle": 0, "type": "code_body" } ], "index": 10, "sub_type": "code", "guess_lang": "c" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 15 }, { "para_blocks": [ { "bbox": [ 86, 74, 505, 102 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 73, 506, 88 ], "spans": [ { "bbox": [ 109, 73, 506, 88 ], "type": "text", "content": "第二个例子是函数 switch_to()（include/asm-x86/system_32.h 文件中），它是 linux", "score": 1.0 } ] }, { "bbox": [ 89, 90, 200, 103 ], "spans": [ { "bbox": [ 89, 90, 200, 103 ], "type": "text", "content": "上下文切换的核心部分：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 105, 505, 404 ], "blocks": [ { "bbox": [ 108, 105, 505, 404 ], "lines": [ { "bbox": [ 108, 105, 505, 404 ], "spans": [ { "bbox": [ 108, 105, 505, 404 ], "type": "text", "content": "1 extern struct task_struct *FASTCALL(_switch_to(struct task_struct *prev, struct task_struct *next)); \n2 #define switch_to(prev, next, last) do { \n3 unsigned long esi,EDI; \n4 asm volatile(\"pushfl\\n\\t\" /* Save flags */ \n5 \"pushl%%ebp\\n\\t\" \n6 \"mov1%%esp,%0\\n\\t\" /* save ESP */ \n7 \"mov1%5,%%esp\\n\\t\" /* restore ESP */ \n8 \"mov1$1f,%1\\n\\t\" /* save EIP */ \n9 \"push1%6\\n\\t\" /* restore EIP */ \n10 \"jmp __switch_to\\n\" \n11 \"1:\\t\" \n12 \"pop1%%ebp\\n\\t\" \n13 \"popfl\" \n14 :=\"m\" (prev->thread.asp), \"=\"m\" (prev->thread.eip), \n15 :=a\" (last),\"=S\" (esi), \"=\"D\" (edi) \n16 : \"m\" (next->thread.asp), \"m\" (next->thread.eip), \n17 \"2\" (prev), \"d\" (next)); \n18 } while (0)" } ] } ], "index": 2, "angle": 0, "type": "code_body" } ], "index": 2, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 108, 407, 240, 420 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 111, 408, 241, 419 ], "spans": [ { "bbox": [ 111, 408, 241, 419 ], "type": "text", "content": "下面对上述代码做简单介绍：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 423, 505, 451 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 423, 505, 437 ], "spans": [ { "bbox": [ 110, 423, 505, 437 ], "type": "text", "content": "第 1 行：FASTCALL 告诉编译程序使用 register 传递参数，而“asmlinkage”标记则要", "score": 1.0 } ] }, { "bbox": [ 89, 439, 200, 452 ], "spans": [ { "bbox": [ 89, 439, 200, 452 ], "type": "text", "content": "求采用stack传递参数；", "score": 1.0 } ] } ] }, { "bbox": [ 108, 455, 267, 467 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 456, 267, 468 ], "spans": [ { "bbox": [ 110, 456, 267, 468 ], "type": "text", "content": "第11行：参数1 被用作返回地址；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 471, 496, 499 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 470, 498, 485 ], "spans": [ { "bbox": [ 109, 470, 498, 485 ], "type": "text", "content": "第 14-15 行：输出参数部分，各参数 prev->thread.esp、prev->thread.eip、last、", "score": 1.0 } ] }, { "bbox": [ 88, 486, 329, 501 ], "spans": [ { "bbox": [ 88, 486, 226, 501 ], "type": "text", "content": "esi、edi 对应的编号分别是：", "score": 1.0 }, { "bbox": [ 226, 487, 239, 499 ], "type": "inline_equation", "content": "\\% 0", "score": 0.57 }, { "bbox": [ 240, 486, 268, 501 ], "type": "text", "content": "、%1、", "score": 1.0 }, { "bbox": [ 269, 487, 282, 498 ], "type": "inline_equation", "content": "\\% 2", "score": 0.68 }, { "bbox": [ 282, 486, 329, 501 ], "type": "text", "content": "、%3、%4；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 502, 501, 547 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 502, 497, 516 ], "spans": [ { "bbox": [ 109, 502, 497, 516 ], "type": "text", "content": "第 16-17 行：输入参数部分，各参数 next->thread.esp、next->thread.eip、prev、", "score": 1.0 } ] }, { "bbox": [ 88, 519, 502, 532 ], "spans": [ { "bbox": [ 88, 519, 205, 532 ], "type": "text", "content": "next对应的编号分别是：", "score": 1.0 }, { "bbox": [ 205, 519, 218, 531 ], "type": "inline_equation", "content": "\\% 5", "score": 0.72 }, { "bbox": [ 218, 519, 268, 532 ], "type": "text", "content": "、%6、%7、", "score": 1.0 }, { "bbox": [ 268, 519, 282, 531 ], "type": "inline_equation", "content": "\\% 8", "score": 0.53 }, { "bbox": [ 282, 519, 502, 532 ], "type": "text", "content": "，其中 34行上的参数prev与输出部中的 2号参", "score": 1.0 } ] }, { "bbox": [ 88, 534, 327, 547 ], "spans": [ { "bbox": [ 88, 534, 327, 547 ], "type": "text", "content": "数使用同一寄存器eax，所以在约束位置填写“2”。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 581, 196, 595 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 88, 582, 196, 595 ], "spans": [ { "bbox": [ 88, 582, 196, 595 ], "type": "text", "content": "6.3 特殊的C 语言用法", "score": 1.0 } ] } ] }, { "bbox": [ 87, 613, 212, 626 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 88, 613, 213, 628 ], "spans": [ { "bbox": [ 88, 613, 213, 628 ], "type": "text", "content": "1.asmlinkage 及 FASTCALL", "score": 1.0 } ] } ] }, { "bbox": [ 86, 643, 505, 672 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 645, 505, 656 ], "spans": [ { "bbox": [ 109, 645, 505, 656 ], "type": "text", "content": "asmlinkage告诉编译程序使用堆栈传递参数，而FASTCALL通知编译程序使用通用寄存", "score": 1.0 } ] }, { "bbox": [ 89, 659, 149, 672 ], "spans": [ { "bbox": [ 89, 659, 149, 672 ], "type": "text", "content": "器传递参数。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 676, 209, 687 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 676, 210, 688 ], "spans": [ { "bbox": [ 110, 676, 210, 688 ], "type": "text", "content": "如获取系统时间函数：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 107, 692, 445, 719 ], "blocks": [ { "bbox": [ 107, 692, 445, 719 ], "lines": [ { "bbox": [ 107, 692, 445, 719 ], "spans": [ { "bbox": [ 107, 692, 445, 719 ], "type": "text", "content": "asmlinkage long sys_gettimeofday(struct timeval __user *tv, structtimezone __user *tz)" } ] } ], "index": 12, "angle": 0, "type": "code_body" } ], "index": 12, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 108, 724, 210, 735 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 724, 210, 736 ], "spans": [ { "bbox": [ 109, 724, 210, 736 ], "type": "text", "content": "实现上下文切换函数：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 96, 740, 502, 768 ], "blocks": [ { "bbox": [ 96, 740, 502, 768 ], "lines": [ { "bbox": [ 96, 740, 502, 768 ], "spans": [ { "bbox": [ 96, 740, 502, 768 ], "type": "text", "content": "struct task_struct FASTCALL * __switch_to(struct task_struct *prev_p, struct task_struct *next_p)" } ] } ], "index": 14, "angle": 0, "type": "code_body" } ], "index": 14, "sub_type": "code", "guess_lang": "txt" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 16 }, { "para_blocks": [ { "bbox": [ 86, 76, 117, 88 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 87, 75, 119, 90 ], "spans": [ { "bbox": [ 87, 75, 119, 90 ], "type": "text", "content": "2. UL", "score": 1.0 } ] } ] }, { "bbox": [ 86, 105, 504, 134 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 106, 505, 119 ], "spans": [ { "bbox": [ 109, 106, 505, 119 ], "type": "text", "content": "UL 常被用在数值常数后，标明该常数是“unsigned long”类型，以保证特定体系结构", "score": 1.0 } ] }, { "bbox": [ 89, 121, 315, 134 ], "spans": [ { "bbox": [ 89, 121, 315, 134 ], "type": "text", "content": "内的数据不会溢出其数据类型所规定的范围。如：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 137, 504, 150 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 137, 505, 151 ], "spans": [ { "bbox": [ 109, 138, 260, 149 ], "type": "text", "content": "#define SLAB_RECLAIM_ACCOUNT", "score": 1.0 }, { "bbox": [ 276, 137, 505, 151 ], "type": "text", "content": "0x00020000UL /* Objects are reclaimable */", "score": 1.0 } ] } ] }, { "bbox": [ 86, 169, 175, 181 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 86, 168, 176, 183 ], "spans": [ { "bbox": [ 86, 168, 176, 183 ], "type": "text", "content": "3. static inline", "score": 1.0 } ] } ] }, { "bbox": [ 86, 199, 504, 243 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 199, 505, 211 ], "spans": [ { "bbox": [ 110, 199, 505, 211 ], "type": "text", "content": "被关键字static inline修饰的函数建议gcc在编译时将其代码插入到所有调用它的程", "score": 1.0 } ] }, { "bbox": [ 88, 215, 505, 227 ], "spans": [ { "bbox": [ 88, 215, 505, 227 ], "type": "text", "content": "序中，从而节省了函数调用的开销。但使用inline会增加二进制映像的大学，可能会降低", "score": 1.0 } ] }, { "bbox": [ 89, 231, 212, 243 ], "spans": [ { "bbox": [ 89, 231, 212, 243 ], "type": "text", "content": "访问CPU高速缓存的速度。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 263, 185, 275 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 88, 261, 186, 277 ], "spans": [ { "bbox": [ 88, 261, 186, 277 ], "type": "text", "content": "4.const 和 volatile", "score": 1.0 } ] } ] }, { "bbox": [ 86, 292, 504, 337 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 292, 505, 305 ], "spans": [ { "bbox": [ 109, 292, 505, 305 ], "type": "text", "content": "const不一定只代表常数，有时也表示“只读”的意思。如“const int *x”中，x是", "score": 1.0 } ] }, { "bbox": [ 89, 306, 503, 322 ], "spans": [ { "bbox": [ 89, 306, 503, 322 ], "type": "text", "content": "一个指向 const 整数的指针，可以修改该指针，但不能修改这个整数；而在“int const *x”", "score": 1.0 } ] }, { "bbox": [ 89, 324, 436, 337 ], "spans": [ { "bbox": [ 89, 324, 436, 337 ], "type": "text", "content": "中，x是一个指向整数的const指针，可以修改该整数，但不能修改指针x。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 339, 504, 368 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 110, 339, 505, 352 ], "spans": [ { "bbox": [ 110, 339, 505, 352 ], "type": "text", "content": "关键字volatile 通知编译程序每次使用被它修饰的变量时都要重新加载其值，而不是", "score": 1.0 } ] }, { "bbox": [ 89, 355, 190, 368 ], "spans": [ { "bbox": [ 89, 355, 190, 368 ], "type": "text", "content": "存储并访问一个副本。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 387, 142, 400 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 87, 386, 145, 401 ], "spans": [ { "bbox": [ 87, 386, 145, 401 ], "type": "text", "content": "5.宏__init", "score": 1.0 } ] } ] }, { "bbox": [ 86, 417, 504, 461 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 417, 504, 428 ], "spans": [ { "bbox": [ 110, 417, 504, 428 ], "type": "text", "content": "宏__init告诉编译程序相关的函数和变量仅用于初始化。编译程序将标有__init的所", "score": 1.0 } ] }, { "bbox": [ 89, 433, 505, 445 ], "spans": [ { "bbox": [ 89, 433, 505, 445 ], "type": "text", "content": "有代码存储到特殊的内存段中，初始化结束后就释放这段内存。如编写模块代码的初始化函", "score": 1.0 } ] }, { "bbox": [ 88, 449, 189, 461 ], "spans": [ { "bbox": [ 88, 449, 189, 461 ], "type": "text", "content": "数时，可以这样定义：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 467, 304, 480 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 109, 466, 305, 481 ], "spans": [ { "bbox": [ 109, 466, 305, 481 ], "type": "text", "content": "static int __init mymodule_init(void)", "score": 1.0 } ] } ] }, { "bbox": [ 86, 482, 504, 510 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 110, 482, 505, 496 ], "spans": [ { "bbox": [ 110, 482, 505, 496 ], "type": "text", "content": "与之类似，如果某些数据也只在初始化时才用到，则可将其标记为__initdata。如ESP", "score": 1.0 } ] }, { "bbox": [ 88, 498, 168, 510 ], "spans": [ { "bbox": [ 88, 498, 168, 510 ], "type": "text", "content": "设备驱动程序中：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 515, 211, 527 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 114, 514, 211, 528 ], "spans": [ { "bbox": [ 114, 514, 211, 528 ], "type": "text", "content": "drivers/char/esp.c", "score": 1.0 } ] } ] }, { "bbox": [ 113, 530, 451, 543 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 113, 528, 453, 544 ], "spans": [ { "bbox": [ 113, 528, 333, 544 ], "type": "text", "content": "109 static char serial_name[] __initdata", "score": 1.0 }, { "bbox": [ 333, 531, 344, 541 ], "type": "inline_equation", "content": "=", "score": 0.65 }, { "bbox": [ 344, 528, 453, 544 ], "type": "text", "content": "\"ESP serial driver\";", "score": 1.0 } ] } ] }, { "bbox": [ 113, 546, 393, 558 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 544, 389, 560 ], "spans": [ { "bbox": [ 114, 544, 349, 560 ], "type": "text", "content": "110 static char serial_version[] __initdata", "score": 1.0 }, { "bbox": [ 349, 545, 389, 558 ], "type": "inline_equation", "content": "\\it { \\Delta } = \\it { \\Delta } ^ { \\prime \\prime } 2 . \\it { \\Delta } 2 ^ { \\prime \\prime }", "score": 0.86 } ] } ] }, { "bbox": [ 86, 561, 504, 591 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 110, 562, 505, 575 ], "spans": [ { "bbox": [ 110, 562, 505, 575 ], "type": "text", "content": "同样，宏__exit和__exitdata仅用于退出和关闭例程，一般在注销设备驱动程序或模", "score": 1.0 } ] }, { "bbox": [ 88, 576, 149, 592 ], "spans": [ { "bbox": [ 88, 576, 149, 592 ], "type": "text", "content": "块时才使用。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 609, 238, 622 ], "type": "title", "angle": 0, "index": 17, "lines": [ { "bbox": [ 86, 608, 239, 624 ], "spans": [ { "bbox": [ 86, 608, 239, 624 ], "type": "text", "content": "6.宏 likely（）和 unlikely（）", "score": 1.0 } ] } ] }, { "bbox": [ 86, 641, 504, 689 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 110, 641, 505, 654 ], "spans": [ { "bbox": [ 110, 641, 505, 654 ], "type": "text", "content": "现代CPU具有精确的启发式分之预测法，她尝试预测下一条到来的命令，以便达到最高", "score": 1.0 } ] }, { "bbox": [ 89, 660, 500, 671 ], "spans": [ { "bbox": [ 89, 660, 500, 671 ], "type": "text", "content": "的速度。宏likely 和unlikely允许开发者通过编译程序告诉CPU：某段代码很可能被执行，", "score": 1.0 } ] }, { "bbox": [ 89, 677, 463, 689 ], "spans": [ { "bbox": [ 89, 677, 463, 689 ], "type": "text", "content": "因而应该预测到；某段代码很可能不被执行，因此不必预测。两个宏的定义如下：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 694, 237, 707 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 110, 694, 238, 708 ], "spans": [ { "bbox": [ 110, 694, 238, 708 ], "type": "text", "content": "include/linux/compiler.h", "score": 1.0 } ] } ] }, { "bbox": [ 107, 712, 351, 724 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 107, 710, 352, 727 ], "spans": [ { "bbox": [ 107, 710, 352, 727 ], "type": "text", "content": "# define likely(x) __builtin_expect(!!(x), 1)", "score": 1.0 } ] } ] }, { "bbox": [ 107, 729, 371, 742 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 107, 727, 373, 744 ], "spans": [ { "bbox": [ 107, 727, 215, 744 ], "type": "text", "content": "# define unlikely(x)", "score": 1.0 }, { "bbox": [ 234, 729, 373, 744 ], "type": "text", "content": "__builtin_expect(!!(x), 0)", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 17 }, { "para_blocks": [ { "bbox": [ 86, 75, 221, 89 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 88, 74, 222, 91 ], "spans": [ { "bbox": [ 88, 74, 222, 91 ], "type": "text", "content": "7．宏 IS_ERR()和 PTR_ERR()", "score": 1.0 } ] } ] }, { "bbox": [ 86, 105, 505, 135 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 105, 505, 119 ], "spans": [ { "bbox": [ 109, 105, 505, 119 ], "type": "text", "content": "这两个宏定义在 include/linux/err.h 中。宏 IS_ ERR 用于判断内核函数的返回值是否", "score": 1.0 } ] }, { "bbox": [ 89, 122, 505, 133 ], "spans": [ { "bbox": [ 89, 122, 505, 133 ], "type": "text", "content": "是一个有效指针，即可用来判断内核代码执行是否有错误；而宏PTR_ERR则返回该错误代码。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 153, 137, 166 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 88, 153, 138, 166 ], "spans": [ { "bbox": [ 88, 153, 138, 166 ], "type": "text", "content": "参考文献：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 185, 503, 232 ], "type": "list", "angle": 0, "index": 6, "blocks": [ { "bbox": [ 107, 185, 465, 198 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 185, 466, 198 ], "spans": [ { "bbox": [ 109, 185, 466, 198 ], "type": "text", "content": "1. 陈莉君，康华.linux操作系统原理与应用.北京：清华大学出版社，2012.", "score": 1.0 } ] } ] }, { "bbox": [ 107, 202, 503, 232 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 107, 202, 505, 216 ], "spans": [ { "bbox": [ 107, 202, 505, 216 ], "type": "text", "content": "2. [美]Claudia Salzberg Rodriguzez,Gordon Fischer,Steven Smolski.linux 内核", "score": 1.0 } ] }, { "bbox": [ 127, 220, 296, 232 ], "spans": [ { "bbox": [ 127, 220, 296, 232 ], "type": "text", "content": "编程.北京：机械工业出版社，2006.", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 139, 298, 462, 319 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 138, 295, 464, 322 ], "spans": [ { "bbox": [ 138, 295, 464, 322 ], "type": "text", "content": "实验一 linux 内核编译及添加系统调用", "score": 1.0 } ] } ] }, { "bbox": [ 114, 345, 280, 361 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 115, 344, 280, 363 ], "spans": [ { "bbox": [ 115, 344, 280, 363 ], "type": "text", "content": "1．1 设计目的和内容要求", "score": 1.0 } ] } ] }, { "bbox": [ 114, 391, 184, 404 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 116, 391, 184, 406 ], "spans": [ { "bbox": [ 116, 391, 184, 406 ], "type": "text", "content": "1．设计目的", "score": 1.0 } ] } ] }, { "bbox": [ 86, 418, 504, 449 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 419, 504, 431 ], "spans": [ { "bbox": [ 109, 419, 504, 431 ], "type": "text", "content": "Linux是开源操作系统，用户可以根据自身系统需要裁剪、修改内核，定制出功能更加", "score": 1.0 } ] }, { "bbox": [ 89, 438, 468, 449 ], "spans": [ { "bbox": [ 89, 438, 468, 449 ], "type": "text", "content": "合适、运行效率更高的系统，因此，编译linux内核是进行内核开发的必要基本功。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 454, 500, 485 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 455, 500, 467 ], "spans": [ { "bbox": [ 110, 455, 500, 467 ], "type": "text", "content": "在系统中根据需要添加新的系统调用是修改内核的一种常用手段，通过本次实验，读", "score": 1.0 } ] }, { "bbox": [ 89, 473, 393, 485 ], "spans": [ { "bbox": [ 89, 473, 393, 485 ], "type": "text", "content": "者应理解linux系统处理系统调用的流程以及增加系统调用的方法。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 495, 184, 507 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 494, 184, 509 ], "spans": [ { "bbox": [ 114, 494, 184, 509 ], "type": "text", "content": "2．内容要求", "score": 1.0 } ] } ] }, { "bbox": [ 86, 522, 504, 552 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 115, 522, 504, 534 ], "spans": [ { "bbox": [ 115, 522, 504, 534 ], "type": "text", "content": "（1）添加一个系统调用，实现对指定进程的 nice 值的修改或读取功能，并返回进程最", "score": 1.0 } ] }, { "bbox": [ 88, 539, 294, 553 ], "spans": [ { "bbox": [ 88, 539, 294, 553 ], "type": "text", "content": "新的nice 值及优先级 prio。建议调用原型为：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 559, 473, 571 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 558, 474, 572 ], "spans": [ { "bbox": [ 109, 558, 474, 572 ], "type": "text", "content": "int mysetnice(pid_t pid, int flag, int nicevalue, void __user * prio, void __user * nice);", "score": 1.0 } ] } ] }, { "bbox": [ 108, 576, 157, 588 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 108, 574, 159, 590 ], "spans": [ { "bbox": [ 108, 574, 159, 590 ], "type": "text", "content": "参数含义：", "score": 1.0 } ] } ] }, { "bbox": [ 128, 594, 193, 607 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 129, 593, 195, 608 ], "spans": [ { "bbox": [ 129, 593, 195, 608 ], "type": "text", "content": "pid：进程 ID。", "score": 1.0 } ] } ] }, { "bbox": [ 127, 612, 423, 624 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 129, 610, 426, 627 ], "spans": [ { "bbox": [ 129, 610, 426, 627 ], "type": "text", "content": "flag：若值为 0，表示读取 nice 值；若值为 1，表示修改 nice 值。", "score": 1.0 } ] } ] }, { "bbox": [ 128, 630, 309, 642 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 129, 629, 311, 644 ], "spans": [ { "bbox": [ 129, 629, 311, 644 ], "type": "text", "content": "Prio、nice：进程当前优先级及 nice 值。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 647, 389, 660 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 646, 390, 662 ], "spans": [ { "bbox": [ 109, 646, 390, 662 ], "type": "text", "content": "返回值：系统调用成功时返回 0，失败时返回错误码 EFAULT。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 666, 430, 696 ], "type": "list", "angle": 0, "index": 22, "blocks": [ { "bbox": [ 112, 666, 379, 678 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 115, 666, 379, 678 ], "spans": [ { "bbox": [ 115, 666, 379, 678 ], "type": "text", "content": "（2）写一个简单的应用程序测试（1）中添加的系统调用。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 683, 430, 696 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 684, 430, 697 ], "spans": [ { "bbox": [ 114, 684, 430, 697 ], "type": "text", "content": "（3）若程序中调用了 linux的内核函数，要求深入阅读相关函数源码。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 113, 705, 250, 719 ], "type": "title", "angle": 0, "index": 23, "lines": [ { "bbox": [ 114, 704, 250, 720 ], "spans": [ { "bbox": [ 114, 704, 250, 720 ], "type": "text", "content": "3. 学时安排（共 4学时）", "score": 1.0 } ] } ] }, { "bbox": [ 113, 736, 189, 750 ], "type": "title", "angle": 0, "index": 24, "lines": [ { "bbox": [ 113, 735, 190, 752 ], "spans": [ { "bbox": [ 113, 735, 190, 752 ], "type": "text", "content": "4． 开发平台", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 18 }, { "para_blocks": [ { "bbox": [ 138, 76, 320, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 139, 75, 321, 91 ], "spans": [ { "bbox": [ 139, 75, 321, 91 ], "type": "text", "content": "Linux 环境，gcc，gdb，vim 或 gedit 等。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 111, 298, 126 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 110, 299, 128 ], "spans": [ { "bbox": [ 114, 110, 299, 128 ], "type": "text", "content": "1．2 Linux 系统调用基本概念", "score": 1.0 } ] } ] }, { "bbox": [ 86, 153, 505, 221 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 111, 153, 499, 166 ], "spans": [ { "bbox": [ 111, 153, 499, 166 ], "type": "text", "content": "系统调用的实质是调用内核函数，于内核态中运行。Linux系统中用户（或封装例程）", "score": 1.0 } ] }, { "bbox": [ 89, 171, 504, 185 ], "spans": [ { "bbox": [ 89, 171, 216, 185 ], "type": "text", "content": "通过执行一条访管指令“int", "score": 1.0 }, { "bbox": [ 217, 171, 250, 184 ], "type": "inline_equation", "content": "\\$ 0 x80", "score": 0.76 }, { "bbox": [ 250, 171, 504, 185 ], "type": "text", "content": "来调用系统调用，该指令会产生一个访管中断，从而让", "score": 1.0 } ] }, { "bbox": [ 89, 190, 499, 201 ], "spans": [ { "bbox": [ 89, 190, 499, 201 ], "type": "text", "content": "系统暂停当前进程的执行，而转去执行系统调用处理程序，通过用户态传入的系统调用号", "score": 1.0 } ] }, { "bbox": [ 89, 208, 498, 220 ], "spans": [ { "bbox": [ 89, 208, 498, 220 ], "type": "text", "content": "从系统调用表中找到相应服务例程的入口并执行，完成后返回。下面介绍相关的基本概念。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 229, 262, 243 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 116, 229, 261, 243 ], "spans": [ { "bbox": [ 116, 229, 261, 243 ], "type": "text", "content": "1.系统调用号与系统调用表", "score": 1.0 } ] } ] }, { "bbox": [ 86, 256, 505, 343 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 109, 257, 503, 269 ], "spans": [ { "bbox": [ 109, 257, 503, 269 ], "type": "text", "content": "Linux系统提供了多达几百种的系统调用，为了唯一的标识每一个系统调用，linux为每", "score": 1.0 } ] }, { "bbox": [ 89, 275, 500, 287 ], "spans": [ { "bbox": [ 89, 275, 500, 287 ], "type": "text", "content": "个系统调用都设置了一个唯一的编号，称为系统调用号；同时每个系统调用需要一个服务", "score": 1.0 } ] }, { "bbox": [ 89, 293, 503, 305 ], "spans": [ { "bbox": [ 89, 293, 503, 305 ], "type": "text", "content": "例程完成其具体功能。Linux内核中设置了一张系统调用表，用于关联系统调用号及其相对", "score": 1.0 } ] }, { "bbox": [ 89, 309, 503, 324 ], "spans": [ { "bbox": [ 89, 309, 503, 324 ], "type": "text", "content": "应的服务例程入口地址，定义在./arch/x86/entry/syscalls/syscall_64.tbl 文件中（32 位系统是", "score": 1.0 } ] }, { "bbox": [ 86, 327, 503, 343 ], "spans": [ { "bbox": [ 86, 327, 503, 343 ], "type": "text", "content": "syscall_32.tbl），每个系统调用占一表项，比如大家比较熟悉的几个系统调用的调用号是：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 102, 359, 418, 537 ], "blocks": [ { "bbox": [ 105, 348, 199, 359 ], "lines": [ { "bbox": [ 107, 348, 199, 359 ], "spans": [ { "bbox": [ 107, 348, 199, 359 ], "type": "text", "content": "表 7-5 系统调用号举例", "score": 1.0 } ] } ], "index": 6, "angle": 0, "type": "table_caption" }, { "bbox": [ 102, 359, 418, 537 ], "lines": [ { "bbox": [ 102, 359, 418, 537 ], "spans": [ { "bbox": [ 102, 359, 418, 537 ], "type": "table", "html": "
系统调用号32 位/64 位/common系统调用名称服务例程入口
0commonreadsys_read
1commonwritesys_write
2commonopensys_open
3commonclosesys_close
57commonforkstub_fork
", "image_path": "af49f661a62dff2aa564d40553e70dd37b423f3c57754d97bb72faccea67a007.jpg" } ] } ], "index": 7, "angle": 0, "type": "table_body" } ], "index": 7 }, { "bbox": [ 86, 541, 504, 591 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 111, 542, 499, 553 ], "spans": [ { "bbox": [ 111, 542, 499, 553 ], "type": "text", "content": "系统调用号非常关键，一旦分配就不能再有任何变更，否则之前编译好的应用程序就", "score": 1.0 } ] }, { "bbox": [ 88, 560, 503, 572 ], "spans": [ { "bbox": [ 88, 560, 503, 572 ], "type": "text", "content": "会崩溃。在x86中，系统调用号是通过eax寄存器传递给内核的。在陷人内核之前，先将系", "score": 1.0 } ] }, { "bbox": [ 89, 578, 481, 590 ], "spans": [ { "bbox": [ 89, 578, 481, 590 ], "type": "text", "content": "统调用号存入eax中，这样系统调用处理程序一旦运行，就可以从 eax中得到调用号。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 599, 232, 613 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 116, 600, 231, 613 ], "spans": [ { "bbox": [ 116, 600, 231, 613 ], "type": "text", "content": "2. 系统调用服务例程", "score": 1.0 } ] } ] }, { "bbox": [ 86, 626, 504, 677 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 627, 499, 639 ], "spans": [ { "bbox": [ 110, 627, 499, 639 ], "type": "text", "content": "每个系统调用都对应一个内核服务例程来实现该系统调用的具体功能，其命名格式都", "score": 1.0 } ] }, { "bbox": [ 88, 644, 504, 658 ], "spans": [ { "bbox": [ 88, 644, 504, 658 ], "type": "text", "content": "是以“sys_”开头，如 sys_read 等，其代码实现通常存放在./kernel/sys.c文件中。服务例程", "score": 1.0 } ] }, { "bbox": [ 88, 662, 498, 677 ], "spans": [ { "bbox": [ 88, 662, 498, 677 ], "type": "text", "content": "的原型声明则是在/include/linux/syscalls.h 中，通常都有固定的格式，如 sys_open 的原型为：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 682, 431, 695 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 108, 681, 432, 695 ], "spans": [ { "bbox": [ 108, 681, 432, 695 ], "type": "text", "content": "asmlinkage long sys_open(const char __user *filename,int flags, int mode);", "score": 1.0 } ] } ] }, { "bbox": [ 86, 698, 505, 766 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 698, 505, 712 ], "spans": [ { "bbox": [ 108, 698, 505, 712 ], "type": "text", "content": "其中“asmlinkage”是一个必须的限定词，用于通知编译器仅从堆栈中提取该函数的参", "score": 1.0 } ] }, { "bbox": [ 89, 718, 499, 729 ], "spans": [ { "bbox": [ 89, 718, 499, 729 ], "type": "text", "content": "数，而不是从寄存器中，因为在执行服务例程之前系统已经将通过寄存器传递过来的参数", "score": 1.0 } ] }, { "bbox": [ 88, 734, 504, 748 ], "spans": [ { "bbox": [ 88, 734, 504, 748 ], "type": "text", "content": "值压入内核堆栈了。在新版本的内核中，引入了宏“SYSCALL_DEFINEN(sname)”对服务例程", "score": 1.0 } ] }, { "bbox": [ 88, 752, 488, 766 ], "spans": [ { "bbox": [ 88, 752, 488, 766 ], "type": "text", "content": "原型进行了封装，其中的“N”是该系统调用所需要参数的个数，如上述sys_open 调用", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 19 }, { "para_blocks": [ { "bbox": [ 86, 76, 261, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 88, 76, 260, 91 ], "spans": [ { "bbox": [ 88, 76, 260, 91 ], "type": "text", "content": "在./kernel/sys.c 文件中的实现格式为：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 95, 434, 108 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 94, 435, 110 ], "spans": [ { "bbox": [ 108, 94, 435, 110 ], "type": "text", "content": "SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, int, mode)", "score": 1.0 } ] } ] }, { "bbox": [ 107, 111, 379, 126 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 112, 377, 126 ], "spans": [ { "bbox": [ 110, 112, 377, 126 ], "type": "text", "content": "如后面添加系统调用示例程序中，服务例程的实现格式为：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 131, 240, 144 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 108, 129, 239, 146 ], "spans": [ { "bbox": [ 108, 129, 239, 146 ], "type": "text", "content": "SYSCALL_DEFINE0(zwhsyscall)", "score": 1.0 } ] } ] }, { "bbox": [ 107, 148, 294, 161 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 148, 294, 161 ], "spans": [ { "bbox": [ 110, 148, 294, 161 ], "type": "text", "content": "本知识点的详细介绍大家可以参考网页：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 166, 358, 179 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 108, 166, 359, 180 ], "spans": [ { "bbox": [ 108, 166, 359, 180 ], "type": "text", "content": "http://blog.csdn.net/adc0809608/article/details/7417180", "score": 1.0 } ] } ] }, { "bbox": [ 113, 188, 233, 201 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 188, 232, 201 ], "spans": [ { "bbox": [ 114, 188, 232, 201 ], "type": "text", "content": "3. 系统调用参数传递", "score": 1.0 } ] } ] }, { "bbox": [ 86, 215, 504, 300 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 111, 216, 503, 227 ], "spans": [ { "bbox": [ 111, 216, 503, 227 ], "type": "text", "content": "与普通函数一样，系统调用通常也需要输入/输出参数。在 x86上，linux通过6 个寄存", "score": 1.0 } ] }, { "bbox": [ 88, 232, 499, 246 ], "spans": [ { "bbox": [ 88, 232, 499, 246 ], "type": "text", "content": "器来传入参数值，其中eax传递系统调用号，后面5个寄存器ebx, ecx, edx, esi和 edi按照", "score": 1.0 } ] }, { "bbox": [ 89, 252, 499, 264 ], "spans": [ { "bbox": [ 89, 252, 499, 264 ], "type": "text", "content": "顺序存放前五个参数，需要六个或六个以上参数的情况不多见，此时，应该用一个单独的", "score": 1.0 } ] }, { "bbox": [ 89, 270, 499, 282 ], "spans": [ { "bbox": [ 89, 270, 499, 282 ], "type": "text", "content": "寄存器存放指向所有这些参数在用户空间地址的指针。服务例程的返回值通过 eax寄存器", "score": 1.0 } ] }, { "bbox": [ 89, 288, 348, 300 ], "spans": [ { "bbox": [ 89, 288, 348, 300 ], "type": "text", "content": "传递，这是在执行rutern指令时由C 编译器自动完成的。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 305, 505, 372 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 111, 306, 503, 317 ], "spans": [ { "bbox": [ 111, 306, 503, 317 ], "type": "text", "content": "当系统调用执行成功时，将返回服务例程的返回值，通常是0。但如果执行失败，为防", "score": 1.0 } ] }, { "bbox": [ 89, 322, 504, 337 ], "spans": [ { "bbox": [ 89, 322, 504, 337 ], "type": "text", "content": "止和正常的返回值混淆，系统调用并不直接返回错误码，而是将错误码放入一个名为 errno", "score": 1.0 } ] }, { "bbox": [ 89, 342, 502, 354 ], "spans": [ { "bbox": [ 89, 342, 502, 354 ], "type": "text", "content": "的全局变量中，通常是一个负值，通过调用perror()库函数，可以把errno翻译成用户可以", "score": 1.0 } ] }, { "bbox": [ 89, 360, 191, 371 ], "spans": [ { "bbox": [ 89, 360, 191, 371 ], "type": "text", "content": "理解的错误信息描述。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 380, 232, 395 ], "type": "title", "angle": 0, "index": 10, "lines": [ { "bbox": [ 115, 381, 232, 395 ], "spans": [ { "bbox": [ 115, 381, 232, 395 ], "type": "text", "content": "4. 系统调用参数验证", "score": 1.0 } ] } ] }, { "bbox": [ 86, 407, 501, 439 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 407, 500, 421 ], "spans": [ { "bbox": [ 110, 407, 500, 421 ], "type": "text", "content": "系统调用必须仔细检查用户传入的参数是否合法有效。比如与进程相关的调用必须检", "score": 1.0 } ] }, { "bbox": [ 90, 427, 230, 439 ], "spans": [ { "bbox": [ 90, 427, 230, 439 ], "type": "text", "content": "查用户提供的PID等是否有效。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 444, 501, 474 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 110, 445, 499, 456 ], "spans": [ { "bbox": [ 110, 445, 499, 456 ], "type": "text", "content": "最重要的是要检查用户提供的指针是否有效，以防止用户进程非法访问数据。内核提", "score": 1.0 } ] }, { "bbox": [ 89, 462, 451, 475 ], "spans": [ { "bbox": [ 89, 462, 451, 475 ], "type": "text", "content": "供了两个函数来完成必须的检查以及内核空间与用户空间之间数据的来回拷贝：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 480, 504, 510 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 88, 478, 505, 496 ], "spans": [ { "bbox": [ 88, 478, 505, 496 ], "type": "text", "content": "copy_to_user()和 copy_from_user()，在较低内核版本中，定义在./arch/x86/lib/usercopy_32.c", "score": 1.0 } ] }, { "bbox": [ 88, 497, 383, 513 ], "spans": [ { "bbox": [ 88, 497, 383, 513 ], "type": "text", "content": "文件中；对于内核 4.12，定义在./include/linux/uaccess.h 文件中：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 513, 216, 527 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 113, 511, 217, 530 ], "spans": [ { "bbox": [ 113, 511, 217, 530 ], "type": "text", "content": "（1） copy_to_user()：", "score": 1.0 } ] } ] }, { "bbox": [ 118, 533, 342, 545 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 119, 532, 342, 547 ], "spans": [ { "bbox": [ 119, 532, 342, 547 ], "type": "text", "content": "static __always_inline unsigned long __must_check", "score": 1.0 } ] } ] }, { "bbox": [ 119, 550, 405, 564 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 119, 549, 406, 566 ], "spans": [ { "bbox": [ 119, 549, 406, 566 ], "type": "text", "content": "copy_to_user(void __user *to, const void *from, unsigned long n);", "score": 1.0 } ] } ] }, { "bbox": [ 119, 567, 321, 580 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 120, 568, 321, 581 ], "spans": [ { "bbox": [ 120, 568, 321, 581 ], "type": "text", "content": "功能：将数据块从内核空间复制到用户空间", "score": 1.0 } ] } ] }, { "bbox": [ 119, 586, 167, 598 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 119, 584, 169, 600 ], "spans": [ { "bbox": [ 119, 584, 169, 600 ], "type": "text", "content": "参数含义：", "score": 1.0 } ] } ] }, { "bbox": [ 128, 603, 282, 616 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 129, 604, 282, 616 ], "spans": [ { "bbox": [ 129, 604, 282, 616 ], "type": "text", "content": "to：用户进程空间中的目的地址；", "score": 1.0 } ] } ] }, { "bbox": [ 128, 622, 247, 634 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 129, 622, 247, 635 ], "spans": [ { "bbox": [ 129, 622, 247, 635 ], "type": "text", "content": "from：内核空间的源地址", "score": 1.0 } ] } ] }, { "bbox": [ 129, 640, 285, 652 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 129, 640, 286, 653 ], "spans": [ { "bbox": [ 129, 640, 286, 653 ], "type": "text", "content": "n：需要拷贝的数据长度(字节数)。", "score": 1.0 } ] } ] }, { "bbox": [ 117, 657, 459, 670 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 120, 658, 461, 671 ], "spans": [ { "bbox": [ 120, 658, 461, 671 ], "type": "text", "content": "返回值：函数执行成功返回 0；如果失败，则返回没有拷贝成功的字节数。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 673, 224, 687 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 113, 669, 225, 691 ], "spans": [ { "bbox": [ 113, 669, 225, 691 ], "type": "text", "content": "（2） copy_from_user()", "score": 1.0 } ] } ] }, { "bbox": [ 118, 692, 342, 705 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 119, 692, 342, 707 ], "spans": [ { "bbox": [ 119, 692, 342, 707 ], "type": "text", "content": "static __always_inline unsigned long __must_check", "score": 1.0 } ] } ] }, { "bbox": [ 119, 710, 417, 723 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 119, 708, 418, 726 ], "spans": [ { "bbox": [ 119, 708, 418, 726 ], "type": "text", "content": "copy_from_user(void *to, const void __user *from, unsigned long n);", "score": 1.0 } ] } ] }, { "bbox": [ 119, 727, 321, 740 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 120, 727, 321, 740 ], "spans": [ { "bbox": [ 120, 727, 321, 740 ], "type": "text", "content": "功能：将数据块从用户空间复制到内核空间", "score": 1.0 } ] } ] }, { "bbox": [ 119, 745, 167, 757 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 119, 744, 168, 759 ], "spans": [ { "bbox": [ 119, 744, 168, 759 ], "type": "text", "content": "参数含义：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 20 }, { "para_blocks": [ { "bbox": [ 127, 76, 250, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 129, 76, 250, 89 ], "spans": [ { "bbox": [ 129, 76, 250, 89 ], "type": "text", "content": "to：内核空间的目的地址；", "score": 1.0 } ] } ] }, { "bbox": [ 127, 95, 247, 106 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 129, 94, 247, 107 ], "spans": [ { "bbox": [ 129, 94, 247, 107 ], "type": "text", "content": "from：用户空间的源地址", "score": 1.0 } ] } ] }, { "bbox": [ 127, 112, 284, 125 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 128, 112, 285, 126 ], "spans": [ { "bbox": [ 128, 112, 285, 126 ], "type": "text", "content": "n：需要拷贝的数据长度(字节数)。", "score": 1.0 } ] } ] }, { "bbox": [ 117, 130, 459, 143 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 119, 130, 460, 143 ], "spans": [ { "bbox": [ 119, 130, 460, 143 ], "type": "text", "content": "返回值：函数执行成功返回 0；如果失败，则返回没有拷贝成功的字节数。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 164, 315, 180 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 116, 164, 317, 182 ], "spans": [ { "bbox": [ 116, 164, 317, 182 ], "type": "text", "content": "1．3 Linux 添加系统调用的步骤：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 206, 504, 255 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 207, 504, 220 ], "spans": [ { "bbox": [ 110, 207, 504, 220 ], "type": "text", "content": "这里以一个很简单的例子说明 linux中添加一个新的系统调用的步骤，该调用没有输入", "score": 1.0 } ] }, { "bbox": [ 88, 225, 502, 238 ], "spans": [ { "bbox": [ 88, 225, 502, 238 ], "type": "text", "content": "参数，名字叫“zwhsyscall”。采用的内核版本是最新的4.12，x86 平台、64位。注意必须", "score": 1.0 } ] }, { "bbox": [ 89, 243, 235, 255 ], "spans": [ { "bbox": [ 89, 243, 235, 255 ], "type": "text", "content": "以root身份才能完成下述操作。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 264, 315, 279 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 116, 264, 315, 280 ], "spans": [ { "bbox": [ 116, 264, 315, 280 ], "type": "text", "content": "1. 分配系统调用号，修改系统调用表", "score": 1.0 } ] } ] }, { "bbox": [ 108, 292, 455, 306 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 108, 291, 455, 307 ], "spans": [ { "bbox": [ 108, 291, 455, 307 ], "type": "text", "content": "查看系统调用表（./arch/x86/entyr/syscalls/syscall_64.tbl），如图 7-16 所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 110, 306, 528, 413 ], "blocks": [ { "bbox": [ 110, 306, 528, 413 ], "lines": [ { "bbox": [ 110, 306, 528, 413 ], "spans": [ { "bbox": [ 110, 306, 528, 413 ], "type": "image", "image_path": "a59459d3c0923ce9087c6dd048f4d7e6e1b53bc6ebd4b8ab1daef9f8c4406e39.jpg" } ] } ], "index": 9, "angle": 0, "type": "image_body" }, { "bbox": [ 108, 419, 244, 431 ], "lines": [ { "bbox": [ 110, 419, 243, 433 ], "spans": [ { "bbox": [ 110, 419, 243, 433 ], "type": "text", "content": "图7-16 系统调用表部分内容", "score": 1.0 } ] } ], "index": 10, "angle": 0, "type": "image_caption" } ], "index": 9 }, { "bbox": [ 108, 437, 304, 450 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 437, 304, 451 ], "spans": [ { "bbox": [ 110, 437, 304, 451 ], "type": "text", "content": "每个系统调用在表中占一表项，其格式为：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 455, 424, 468 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 455, 424, 470 ], "spans": [ { "bbox": [ 109, 455, 319, 470 ], "type": "text", "content": "<系统调用号> <系统调用名", "score": 1.0 }, { "bbox": [ 320, 456, 334, 467 ], "type": "inline_equation", "content": "> <", "score": 0.75 }, { "bbox": [ 334, 455, 424, 470 ], "type": "text", "content": "<服务例程入口地址>", "score": 1.0 } ] } ] }, { "bbox": [ 86, 473, 501, 523 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 110, 474, 499, 485 ], "spans": [ { "bbox": [ 110, 474, 499, 485 ], "type": "text", "content": "选择一个未使用的系统调用号进行分配，比如当前系统使用到 332 号，则新添加的系", "score": 1.0 } ] }, { "bbox": [ 89, 492, 499, 503 ], "spans": [ { "bbox": [ 89, 492, 499, 503 ], "type": "text", "content": "统调用可使用333号。确定调用号后，应在系统调用表中关联新调用的调用号与服务例程", "score": 1.0 } ] }, { "bbox": [ 89, 509, 465, 522 ], "spans": [ { "bbox": [ 89, 509, 465, 522 ], "type": "text", "content": "入口，即在syscall_64.tbl文件中为新调用添加一条记录，修改结果如图7-17所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 90, 528, 496, 611 ], "blocks": [ { "bbox": [ 90, 528, 496, 611 ], "lines": [ { "bbox": [ 90, 528, 496, 611 ], "spans": [ { "bbox": [ 90, 528, 496, 611 ], "type": "image", "image_path": "efd0422062519c1226de617798fa474fd3a1b02219447cdd3caaf03884ed5d62.jpg" } ] } ], "index": 14, "angle": 0, "type": "image_body" }, { "bbox": [ 198, 622, 302, 634 ], "lines": [ { "bbox": [ 201, 623, 302, 634 ], "spans": [ { "bbox": [ 201, 623, 302, 634 ], "type": "text", "content": "图 7-17 修改系统调用表", "score": 1.0 } ] } ], "index": 15, "angle": 0, "type": "image_caption" } ], "index": 14 }, { "bbox": [ 113, 642, 280, 656 ], "type": "title", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 642, 280, 657 ], "spans": [ { "bbox": [ 114, 642, 280, 657 ], "type": "text", "content": "2. 申明系统调用服务例程原型", "score": 1.0 } ] } ] }, { "bbox": [ 86, 670, 504, 700 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 669, 504, 684 ], "spans": [ { "bbox": [ 109, 669, 504, 684 ], "type": "text", "content": "Linux 系统调用服务例程的原型声明在文件 linux-4.12/include/linux/syscalls.h 中，可在文", "score": 1.0 } ] }, { "bbox": [ 89, 688, 235, 700 ], "spans": [ { "bbox": [ 89, 688, 235, 700 ], "type": "text", "content": "件末尾添加如图7-18 所示内容：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 110, 707, 141, 727 ], "blocks": [ { "bbox": [ 110, 707, 141, 727 ], "lines": [ { "bbox": [ 110, 707, 141, 727 ], "spans": [ { "bbox": [ 110, 707, 141, 727 ], "type": "image", "image_path": "9e858592f4080a0633cfc441808778dbc28597710536a8c77d13c01e9a8ad6e2.jpg" } ] } ], "index": 18, "angle": 0, "type": "image_body" }, { "bbox": [ 105, 738, 250, 750 ], "lines": [ { "bbox": [ 107, 739, 249, 750 ], "spans": [ { "bbox": [ 107, 739, 249, 750 ], "type": "text", "content": "图 7-18 声明系统调用服务例程原型", "score": 1.0 } ] } ], "index": 20, "angle": 0, "type": "image_caption" } ], "index": 18 }, { "bbox": [ 145, 710, 349, 724 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 143, 709, 349, 725 ], "spans": [ { "bbox": [ 143, 709, 349, 725 ], "type": "text", "content": "asmlinkage long sys_zwhsyscall(void);", "score": 0.996 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 21 }, { "para_blocks": [ { "bbox": [ 113, 79, 249, 93 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 115, 80, 249, 94 ], "spans": [ { "bbox": [ 115, 80, 249, 94 ], "type": "text", "content": "3.实现系统调用服务例程", "score": 1.0 } ] } ] }, { "bbox": [ 86, 106, 503, 137 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 106, 503, 121 ], "spans": [ { "bbox": [ 110, 106, 503, 121 ], "type": "text", "content": "下面为新调用 zwhsyscall 编写服务例程 sys_zwhsyscall，通常添加在 sys.c 文件中，其完", "score": 1.0 } ] }, { "bbox": [ 88, 124, 321, 139 ], "spans": [ { "bbox": [ 88, 124, 321, 139 ], "type": "text", "content": "整路径为：linux-4.12/kernel/sys.c，如图 7-19 所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 110, 142, 413, 212 ], "blocks": [ { "bbox": [ 110, 142, 413, 212 ], "lines": [ { "bbox": [ 110, 142, 413, 212 ], "spans": [ { "bbox": [ 110, 142, 413, 212 ], "type": "image", "image_path": "afdc250564f749d75b4dad48af714b9f7481ac457d05a22252977b108081e5ee.jpg" } ] } ], "index": 3, "angle": 0, "type": "image_body" }, { "bbox": [ 167, 222, 293, 233 ], "lines": [ { "bbox": [ 170, 222, 293, 234 ], "spans": [ { "bbox": [ 170, 222, 293, 234 ], "type": "text", "content": "图 7-19 编写系统调用服务例程", "score": 1.0 } ] } ], "index": 4, "angle": 0, "type": "image_caption" } ], "index": 3 }, { "bbox": [ 113, 243, 208, 257 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 115, 243, 208, 257 ], "spans": [ { "bbox": [ 115, 243, 208, 257 ], "type": "text", "content": "4. 重新编译内核", "score": 1.0 } ] } ] }, { "bbox": [ 86, 270, 499, 301 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 111, 271, 499, 282 ], "spans": [ { "bbox": [ 111, 271, 499, 282 ], "type": "text", "content": "上面三个步骤已经完成添加一个新系统调用的所有工作，但是要让这个系统调用真正", "score": 1.0 } ] }, { "bbox": [ 89, 288, 478, 301 ], "spans": [ { "bbox": [ 89, 288, 478, 301 ], "type": "text", "content": "在内核中运行起来，还需要重新编译内核。有关内核编译的知识，见7.2.4 节的介绍。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 310, 303, 323 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 115, 310, 303, 324 ], "spans": [ { "bbox": [ 115, 310, 303, 324 ], "type": "text", "content": "5. 编写用户态程序测试新系统调用", "score": 1.0 } ] } ] }, { "bbox": [ 108, 338, 357, 350 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 110, 338, 358, 350 ], "spans": [ { "bbox": [ 110, 338, 358, 350 ], "type": "text", "content": "可编写一个用户态程序来调用上面新添加的系统调用：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 356, 446, 476 ], "type": "list", "angle": 0, "index": 16, "blocks": [ { "bbox": [ 107, 356, 233, 369 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 107, 354, 234, 371 ], "spans": [ { "bbox": [ 107, 354, 234, 371 ], "type": "text", "content": "1 #define _GNU_SOURCE", "score": 1.0 } ] } ] }, { "bbox": [ 108, 375, 241, 386 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 107, 374, 241, 388 ], "spans": [ { "bbox": [ 107, 374, 241, 388 ], "type": "text", "content": "2 #include ", "score": 1.0 } ] } ] }, { "bbox": [ 108, 392, 234, 404 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 107, 391, 235, 407 ], "spans": [ { "bbox": [ 107, 391, 235, 407 ], "type": "text", "content": "3 #include ", "score": 1.0 } ] } ] }, { "bbox": [ 107, 409, 446, 423 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 107, 409, 447, 424 ], "spans": [ { "bbox": [ 107, 409, 447, 424 ], "type": "text", "content": "4 #define __NR_mysyscall 333 /*系统调用号根据实验具体数字而定*/", "score": 1.0 } ] } ] }, { "bbox": [ 108, 428, 183, 440 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 107, 426, 184, 444 ], "spans": [ { "bbox": [ 107, 426, 184, 444 ], "type": "text", "content": "5 int main() {", "score": 1.0 } ] } ] }, { "bbox": [ 107, 445, 355, 459 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 445, 355, 461 ], "spans": [ { "bbox": [ 109, 446, 117, 459 ], "type": "text", "content": "6", "score": 1.0 }, { "bbox": [ 152, 445, 355, 461 ], "type": "text", "content": "syscall(__NR_mysyscall); /*或 syscall(333) */", "score": 1.0 } ] } ] }, { "bbox": [ 108, 464, 136, 476 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 108, 462, 139, 480 ], "spans": [ { "bbox": [ 108, 462, 139, 480 ], "type": "text", "content": "7 }", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 481, 157, 493 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 481, 158, 495 ], "spans": [ { "bbox": [ 109, 481, 158, 495 ], "type": "text", "content": "程序说明：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 499, 498, 530 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 110, 500, 499, 513 ], "spans": [ { "bbox": [ 110, 500, 499, 513 ], "type": "text", "content": "程序第 6 行使用了 syscall()宏调用新添加的系统调用，它是 linux 提供给用户态程序直", "score": 1.0 } ] }, { "bbox": [ 89, 518, 271, 529 ], "spans": [ { "bbox": [ 89, 518, 271, 529 ], "type": "text", "content": "接调用系统调用的一种方法，其格式为：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 536, 222, 549 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 108, 534, 223, 552 ], "spans": [ { "bbox": [ 108, 534, 223, 552 ], "type": "text", "content": "int syscall(int number, ...);", "score": 1.0 } ] } ] }, { "bbox": [ 107, 553, 464, 566 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 110, 553, 466, 567 ], "spans": [ { "bbox": [ 110, 553, 466, 567 ], "type": "text", "content": "其中number是系统调用号，number后面应顺序接上该系统调用的所有参数。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 571, 436, 584 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 109, 571, 436, 585 ], "spans": [ { "bbox": [ 109, 571, 436, 585 ], "type": "text", "content": "编译该程序并运行后，使用 dmesg命令查看输出内容，如图7-20所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 106, 586, 431, 630 ], "blocks": [ { "bbox": [ 106, 586, 431, 630 ], "lines": [ { "bbox": [ 106, 586, 431, 630 ], "spans": [ { "bbox": [ 106, 586, 431, 630 ], "type": "image", "image_path": "9683c7f5a64052a891b7bcf0584365b3f319d43213c32d52f38e9e96807f6ed4.jpg" } ] } ], "index": 22, "angle": 0, "type": "image_body" }, { "bbox": [ 190, 637, 298, 649 ], "lines": [ { "bbox": [ 192, 638, 298, 650 ], "spans": [ { "bbox": [ 192, 638, 298, 650 ], "type": "text", "content": "图 7-20 系统调用测试结果", "score": 1.0 } ] } ], "index": 23, "angle": 0, "type": "image_caption" } ], "index": 22 }, { "bbox": [ 114, 671, 270, 686 ], "type": "title", "angle": 0, "index": 24, "lines": [ { "bbox": [ 116, 671, 270, 687 ], "spans": [ { "bbox": [ 116, 671, 270, 687 ], "type": "text", "content": "1．4 Linux 内核编译步骤", "score": 1.0 } ] } ] }, { "bbox": [ 86, 713, 499, 761 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 109, 713, 499, 726 ], "spans": [ { "bbox": [ 109, 713, 499, 726 ], "type": "text", "content": "作为自由软件，linux 内核版本不断更新，新内核会修订旧内核的bug，并增加若干新", "score": 1.0 } ] }, { "bbox": [ 89, 731, 499, 744 ], "spans": [ { "bbox": [ 89, 731, 499, 744 ], "type": "text", "content": "特性，如支持更多的硬件、具备更好的系统管理能力、运行速度更快、更稳定等。用户若", "score": 1.0 } ] }, { "bbox": [ 89, 749, 500, 761 ], "spans": [ { "bbox": [ 89, 749, 500, 761 ], "type": "text", "content": "想使用这些新特性，或希望根据自身系统需求定制一个更高效、更稳定的内核，就需要重", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 22 }, { "para_blocks": [ { "bbox": [ 86, 76, 472, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 89, 76, 473, 89 ], "spans": [ { "bbox": [ 89, 76, 473, 89 ], "type": "text", "content": "新编译内核。下面以linux初学者喜欢使用的ubuntu系统为例，介绍内核编译步骤。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 98, 178, 111 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 115, 98, 178, 113 ], "spans": [ { "bbox": [ 115, 98, 178, 113 ], "type": "text", "content": "1.实验环境", "score": 1.0 } ] } ] }, { "bbox": [ 107, 125, 494, 138 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 123, 494, 140 ], "spans": [ { "bbox": [ 108, 123, 494, 140 ], "type": "text", "content": "Ubuntu 64 位：ubuntu-16.04-desktop-amd64.iso，待编译的新内核是 linux-4.12.tar.xz。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 143, 312, 156 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 142, 311, 158 ], "spans": [ { "bbox": [ 110, 142, 311, 158 ], "type": "text", "content": "虚拟机：WMware-player-12.1.1-3770994.exe", "score": 1.0 } ] } ] }, { "bbox": [ 86, 161, 501, 210 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 161, 499, 174 ], "spans": [ { "bbox": [ 110, 162, 269, 173 ], "type": "text", "content": "虚拟机的建议配置参数：磁盘空间", "score": 1.0 }, { "bbox": [ 269, 161, 328, 174 ], "type": "inline_equation", "content": "3 0 6 8 { \\sim } 4 0 6 8", "score": 0.78 }, { "bbox": [ 329, 162, 499, 173 ], "type": "text", "content": "以上，内存2GB以上。由于在内核编", "score": 1.0 } ] }, { "bbox": [ 89, 180, 499, 190 ], "spans": [ { "bbox": [ 89, 180, 499, 190 ], "type": "text", "content": "译过程中会生成较多的临时文件，如果磁盘空间预留太小，会出现磁盘空间不足的错误而", "score": 1.0 } ] }, { "bbox": [ 89, 197, 454, 210 ], "spans": [ { "bbox": [ 89, 197, 405, 210 ], "type": "text", "content": "导致内核编译失败；内存太小会影响编译速度，一般内核编译时间是", "score": 1.0 }, { "bbox": [ 406, 197, 448, 210 ], "type": "inline_equation", "content": "1 . 5 \\mathsf { h } { \\sim } 3 \\mathsf { h }", "score": 0.79 }, { "bbox": [ 448, 197, 454, 210 ], "type": "text", "content": "。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 219, 202, 232 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 114, 219, 202, 233 ], "spans": [ { "bbox": [ 114, 219, 202, 233 ], "type": "text", "content": "2.下载内核源码", "score": 1.0 } ] } ] }, { "bbox": [ 86, 246, 504, 277 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 110, 248, 503, 259 ], "spans": [ { "bbox": [ 110, 248, 503, 259 ], "type": "text", "content": "Linux的内核源代码是完全公开的，有很多网站都提供源码下载，推荐使用 linux的官方", "score": 1.0 } ] }, { "bbox": [ 88, 264, 458, 279 ], "spans": [ { "bbox": [ 88, 264, 458, 279 ], "type": "text", "content": "网站：http://www.kernel.org，在这里可以找到所有的内核版本，如图 7-21 所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 110, 280, 530, 464 ], "blocks": [ { "bbox": [ 110, 280, 530, 464 ], "lines": [ { "bbox": [ 110, 280, 530, 464 ], "spans": [ { "bbox": [ 110, 280, 530, 464 ], "type": "image", "image_path": "c94095dac0782a7653400af87d218cb03e86cf4444184127fe8d1268e397de54.jpg" } ] } ], "index": 8, "angle": 0, "type": "image_body" }, { "bbox": [ 163, 470, 253, 482 ], "lines": [ { "bbox": [ 165, 470, 252, 483 ], "spans": [ { "bbox": [ 165, 470, 252, 483 ], "type": "text", "content": "图 7-21 linux 官方网站", "score": 1.0 } ] } ], "index": 9, "angle": 0, "type": "image_caption" } ], "index": 8 }, { "bbox": [ 113, 491, 238, 505 ], "type": "title", "angle": 0, "index": 10, "lines": [ { "bbox": [ 115, 491, 238, 506 ], "spans": [ { "bbox": [ 115, 491, 238, 506 ], "type": "text", "content": "3.解压缩内核源码文件", "score": 1.0 } ] } ] }, { "bbox": [ 86, 515, 505, 544 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 516, 506, 528 ], "spans": [ { "bbox": [ 110, 516, 506, 528 ], "type": "text", "content": "首先切换到 root 用户，将下载的新内核压缩文件复制到/home 或其他比较空闲的目录", "score": 1.0 } ] }, { "bbox": [ 89, 532, 325, 543 ], "spans": [ { "bbox": [ 89, 532, 325, 543 ], "type": "text", "content": "中，然后进入压缩文件所在子目录，分两步解压缩：", "score": 1.0 } ] } ] }, { "bbox": [ 119, 546, 481, 574 ], "type": "list", "angle": 0, "index": 14, "blocks": [ { "bbox": [ 119, 546, 481, 559 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 121, 546, 482, 560 ], "spans": [ { "bbox": [ 121, 546, 482, 560 ], "type": "text", "content": "（1） # xz -d linux-4.4.19.tar.xz 大概执行 1 分钟左右，中间没有任何信息显示。", "score": 1.0 } ] } ] }, { "bbox": [ 120, 562, 262, 574 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 120, 560, 264, 577 ], "spans": [ { "bbox": [ 120, 560, 264, 577 ], "type": "text", "content": "（2） # tar -xvf linux-4.4.19.tar", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 577, 505, 606 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 578, 505, 589 ], "spans": [ { "bbox": [ 110, 578, 505, 589 ], "type": "text", "content": "注意：由于编译过程中会生成很多临时文件，所以要确保压缩文件所在子目录有足够的", "score": 1.0 } ] }, { "bbox": [ 89, 594, 436, 605 ], "spans": [ { "bbox": [ 89, 594, 436, 605 ], "type": "text", "content": "空闲空间，最好能有15-20GB。笔者在建立虚拟机时预留了40GB磁盘空间。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 616, 293, 630 ], "type": "title", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 615, 293, 632 ], "spans": [ { "bbox": [ 114, 615, 293, 632 ], "type": "text", "content": "4. 清除残留的.config 和.o 文件", "score": 1.0 } ] } ] }, { "bbox": [ 86, 640, 505, 668 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 111, 640, 505, 653 ], "spans": [ { "bbox": [ 111, 640, 505, 653 ], "type": "text", "content": "当编译出错需要重新编译或不是第一次编译，都需要清除残留的.config 和.o 文件，方", "score": 1.0 } ] }, { "bbox": [ 89, 656, 304, 667 ], "spans": [ { "bbox": [ 89, 656, 304, 667 ], "type": "text", "content": "法是进入linux-4.12子目录，执行以下命令：", "score": 1.0 } ] } ] }, { "bbox": [ 149, 671, 236, 684 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 149, 670, 236, 687 ], "spans": [ { "bbox": [ 149, 670, 236, 687 ], "type": "text", "content": "# make mrproper", "score": 1.0 } ] } ] }, { "bbox": [ 86, 687, 505, 714 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 108, 685, 506, 702 ], "spans": [ { "bbox": [ 108, 685, 506, 702 ], "type": "text", "content": "这里可能会提醒安装 ncurses 包，在 ubuntu 中 ncurses 库的名字是 libncurses5-dev，所", "score": 1.0 } ] }, { "bbox": [ 89, 703, 158, 715 ], "spans": [ { "bbox": [ 89, 703, 158, 715 ], "type": "text", "content": "以安装命令是：", "score": 1.0 } ] } ] }, { "bbox": [ 149, 719, 286, 731 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 151, 719, 287, 732 ], "spans": [ { "bbox": [ 151, 719, 287, 732 ], "type": "text", "content": "#apt-get install libncurses5-dev", "score": 1.0 } ] } ] }, { "bbox": [ 108, 737, 291, 750 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 109, 735, 292, 753 ], "spans": [ { "bbox": [ 109, 735, 292, 753 ], "type": "text", "content": "安装完成后再次执行：# make mrproper", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 23 }, { "para_blocks": [ { "bbox": [ 113, 79, 184, 93 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 114, 79, 185, 95 ], "spans": [ { "bbox": [ 114, 79, 185, 95 ], "type": "text", "content": "5. 配置内核", "score": 1.0 } ] } ] }, { "bbox": [ 108, 104, 248, 116 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 101, 248, 120 ], "spans": [ { "bbox": [ 108, 101, 248, 120 ], "type": "text", "content": "运行命令：# make menuconfig", "score": 1.0 } ] } ] }, { "bbox": [ 108, 119, 370, 131 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 120, 371, 132 ], "spans": [ { "bbox": [ 110, 120, 371, 132 ], "type": "text", "content": "运行该命令过程中，可能会出现如图 7-22 所示错误信息：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 110, 135, 503, 242 ], "blocks": [ { "bbox": [ 110, 135, 503, 242 ], "lines": [ { "bbox": [ 110, 135, 503, 242 ], "spans": [ { "bbox": [ 110, 135, 503, 242 ], "type": "text", "content": "root@ubuntu:/usr/src/linux-source-4.4.0# make menuconfig \nHOSTCC scripts/basic/fixdep \nHOSTCC scripts/kconfig/mconf.o \nIn file included from scripts/kconfig/mconf.c:23:0: \nscripts/kconfig/lxdialog/dialog.h:38:20: fatal error: curses.h: No such file or directory \ncompilation terminated. \nscripts/Makefile.host:108: recipe for target 'scripts/kconfig/mconf.o' failed \nmake[1]: *** [scripts/kconfig/mconf.o] Error 1 \nMakefile:541: recipe for target 'menuconfig' failed \nmake: *** [menuconfig] Error 2" } ] } ], "index": 4, "angle": 0, "type": "code_body" } ], "index": 4, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 108, 244, 278, 256 ], "lines": [ { "bbox": [ 110, 244, 279, 257 ], "spans": [ { "bbox": [ 110, 244, 279, 257 ], "type": "text", "content": "图 7-22 缺少套件 ncurses devel 的错误信息", "score": 1.0 } ] } ], "index": 5, "angle": 0, "type": "text" }, { "bbox": [ 107, 259, 474, 273 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 259, 476, 274 ], "spans": [ { "bbox": [ 109, 259, 476, 274 ], "type": "text", "content": "这是因为 Ubuntu 系统中可能缺少一个套件 ncurses devel，安装方法是执行命令：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 276, 246, 288 ], "blocks": [ { "bbox": [ 108, 276, 246, 288 ], "lines": [ { "bbox": [ 108, 276, 246, 288 ], "spans": [ { "bbox": [ 108, 276, 246, 288 ], "type": "text", "content": "apt-get install libncurses5-dev" } ] } ], "index": 7, "angle": 0, "type": "code_body" } ], "index": 7, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 86, 290, 504, 365 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 290, 506, 305 ], "spans": [ { "bbox": [ 109, 290, 506, 305 ], "type": "text", "content": "之后再执行“make menuconfig”命令将打开如图 7-23 所示配置对话框，对于每一个配", "score": 1.0 } ] }, { "bbox": [ 89, 307, 505, 320 ], "spans": [ { "bbox": [ 89, 307, 505, 320 ], "type": "text", "content": "置选项，用户可以回答\"y\"、\"m\"或\"n\"：其中\"y\"表示将相应特性的支持或设备驱动程序编译", "score": 1.0 } ] }, { "bbox": [ 88, 322, 505, 334 ], "spans": [ { "bbox": [ 88, 322, 505, 334 ], "type": "text", "content": "进内核；\"m\"表示将相应特性的支持或设备驱动程序编译成可加载模块，在需要时，可由系", "score": 1.0 } ] }, { "bbox": [ 89, 338, 505, 350 ], "spans": [ { "bbox": [ 89, 338, 505, 350 ], "type": "text", "content": "统或用户自行加入到内核中去；\"n\"表示内核不提供相应特性或驱动程序的支持。一般采用", "score": 1.0 } ] }, { "bbox": [ 88, 354, 403, 366 ], "spans": [ { "bbox": [ 88, 354, 403, 366 ], "type": "text", "content": "默认值即可：选择保存配置信息，然后选择退出对话框。", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 110, 369, 457, 552 ], "blocks": [ { "bbox": [ 110, 369, 457, 552 ], "lines": [ { "bbox": [ 110, 369, 457, 552 ], "spans": [ { "bbox": [ 110, 369, 457, 552 ], "type": "image", "image_path": "f3f60ad7499943aa7850542d05627738e94d1d47df174b2a3141aa476ffa809e.jpg" } ] } ], "index": 9, "angle": 0, "type": "image_body" }, { "bbox": [ 187, 712, 264, 724 ], "lines": [ { "bbox": [ 190, 713, 264, 724 ], "spans": [ { "bbox": [ 190, 713, 264, 724 ], "type": "text", "content": "图 7-24 编译错误", "score": 1.0 } ] } ], "index": 16, "angle": 0, "type": "image_caption" } ], "index": 9 }, { "bbox": [ 261, 555, 351, 567 ], "lines": [ { "bbox": [ 264, 557, 351, 568 ], "spans": [ { "bbox": [ 264, 557, 351, 568 ], "type": "text", "content": "图 7-23 配置内核界面", "score": 1.0 } ] } ], "index": 10, "angle": 0, "type": "text" }, { "bbox": [ 113, 578, 292, 592 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 115, 578, 292, 593 ], "spans": [ { "bbox": [ 115, 578, 292, 593 ], "type": "text", "content": "6. 编译内核，生成启动映像文件", "score": 1.0 } ] } ] }, { "bbox": [ 86, 602, 505, 631 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 602, 506, 617 ], "spans": [ { "bbox": [ 109, 602, 506, 617 ], "type": "text", "content": "内 核 配 置 完 成 后 ， 编 译 内 核 ， 并 生 成 启 动 映 像 文 件 bzImage （ 位", "score": 1.0 } ] }, { "bbox": [ 89, 618, 234, 632 ], "spans": [ { "bbox": [ 89, 618, 234, 632 ], "type": "text", "content": "于./arch/x86_64/boot/bzImage）：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 634, 194, 645 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 108, 633, 195, 649 ], "spans": [ { "bbox": [ 108, 633, 195, 649 ], "type": "text", "content": "执行命令：# make", "score": 1.0 } ] } ] }, { "bbox": [ 108, 649, 483, 661 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 650, 483, 663 ], "spans": [ { "bbox": [ 109, 650, 483, 663 ], "type": "text", "content": "如果是多核cpu可使用 make -j来加快编译速度。可能会出现图7-24 所示的错误：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 667, 520, 704 ], "blocks": [ { "bbox": [ 108, 667, 520, 704 ], "lines": [ { "bbox": [ 108, 667, 520, 704 ], "spans": [ { "bbox": [ 108, 667, 520, 704 ], "type": "text", "content": "CALE scripts/checksyscalts.sh \nHOSTCC scripts/sign-file \nscripts/sign-file.c:23:30: fatal error:openssl/opensslv.h: No such file or direc tory" } ] } ], "index": 15, "angle": 0, "type": "code_body" } ], "index": 15, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 107, 727, 348, 740 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 726, 349, 742 ], "spans": [ { "bbox": [ 109, 726, 349, 742 ], "type": "text", "content": "这是因为没有安装 openssl， openssl 的安装方法是：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 743, 271, 756 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 741, 273, 758 ], "spans": [ { "bbox": [ 109, 741, 273, 758 ], "type": "text", "content": "执行命令：# apt-get install libssl-dev", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 24 }, { "para_blocks": [ { "bbox": [ 86, 76, 502, 107 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 108, 76, 503, 89 ], "spans": [ { "bbox": [ 108, 76, 503, 89 ], "type": "text", "content": "openssl安装完成后，再执行 make 命令即可，需要较长时间，笔者4核处理器，用了", "score": 1.0 } ] }, { "bbox": [ 88, 93, 143, 108 ], "spans": [ { "bbox": [ 88, 93, 143, 108 ], "type": "text", "content": "约 20 分钟。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 116, 184, 130 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 115, 116, 185, 131 ], "spans": [ { "bbox": [ 115, 116, 185, 131 ], "type": "text", "content": "7. 编译模块", "score": 1.0 } ] } ] }, { "bbox": [ 108, 140, 235, 152 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 139, 235, 154 ], "spans": [ { "bbox": [ 108, 139, 235, 154 ], "type": "text", "content": "执行命令：# make modules", "score": 1.0 } ] } ] }, { "bbox": [ 107, 155, 378, 168 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 156, 379, 169 ], "spans": [ { "bbox": [ 110, 156, 379, 169 ], "type": "text", "content": "第一次编译模块需要很长时间，笔者大概用了两个半小时。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 178, 184, 191 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 178, 184, 193 ], "spans": [ { "bbox": [ 114, 178, 184, 193 ], "type": "text", "content": "8. 安装内核", "score": 1.0 } ] } ] }, { "bbox": [ 113, 202, 290, 230 ], "type": "list", "angle": 0, "index": 8, "blocks": [ { "bbox": [ 113, 202, 290, 215 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 114, 201, 291, 216 ], "spans": [ { "bbox": [ 114, 201, 291, 216 ], "type": "text", "content": "（1）安装模块：# make modules_install", "score": 1.0 } ] } ] }, { "bbox": [ 113, 218, 246, 230 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 216, 246, 232 ], "spans": [ { "bbox": [ 114, 216, 246, 232 ], "type": "text", "content": "（2）安装内核：#make install", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 113, 241, 231, 254 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 240, 232, 256 ], "spans": [ { "bbox": [ 114, 240, 232, 256 ], "type": "text", "content": "9.配置 grub 引导程序", "score": 1.0 } ] } ] }, { "bbox": [ 108, 264, 381, 278 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 264, 383, 280 ], "spans": [ { "bbox": [ 110, 264, 383, 280 ], "type": "text", "content": "只需要执行命令：# update-grub2，该命令会自动修改 grub。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 287, 185, 301 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 116, 287, 185, 302 ], "spans": [ { "bbox": [ 116, 287, 185, 302 ], "type": "text", "content": "10.重启系统", "score": 1.0 } ] } ] }, { "bbox": [ 108, 312, 201, 323 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 311, 202, 325 ], "spans": [ { "bbox": [ 108, 311, 202, 325 ], "type": "text", "content": "执行命令：# reboot", "score": 1.0 } ] } ] }, { "bbox": [ 107, 327, 467, 339 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 327, 468, 340 ], "spans": [ { "bbox": [ 109, 327, 468, 340 ], "type": "text", "content": "将使用新内核启动 linux。启动完成后进入终端查看内核版本，如图7-25 所示：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 89, 343, 506, 386 ], "blocks": [ { "bbox": [ 89, 343, 506, 386 ], "lines": [ { "bbox": [ 89, 343, 506, 386 ], "spans": [ { "bbox": [ 89, 343, 506, 386 ], "type": "text", "content": "zwh@ubuntu:~$ uname -a Linuxubuntu 4.12.0 #1 SMP Sat Jul 8 20:23:38 PDT 2017 x86_64 x86_64 x86_64 GNU/Linux zwh@ubuntu:~$" } ] } ], "index": 14, "angle": 0, "type": "code_body" } ], "index": 14, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 205, 390, 299, 401 ], "angle": 0, "index": 15, "lines": [ { "bbox": [ 207, 390, 299, 401 ], "spans": [ { "bbox": [ 207, 390, 299, 401 ], "type": "text", "content": "图 7-25 查看内核版本", "score": 1.0 } ] } ], "type": "text" }, { "bbox": [ 184, 468, 418, 488 ], "type": "title", "angle": 0, "index": 16, "lines": [ { "bbox": [ 184, 465, 420, 492 ], "spans": [ { "bbox": [ 184, 465, 246, 492 ], "type": "text", "content": "实验二", "score": 1.0 }, { "bbox": [ 255, 466, 420, 491 ], "type": "text", "content": "linux 内核模块编程", "score": 1.0 } ] } ] }, { "bbox": [ 114, 515, 280, 531 ], "type": "title", "angle": 0, "index": 17, "lines": [ { "bbox": [ 114, 514, 281, 533 ], "spans": [ { "bbox": [ 114, 514, 281, 533 ], "type": "text", "content": "2.1 设计目的和内容要求", "score": 1.0 } ] } ] }, { "bbox": [ 108, 562, 170, 574 ], "type": "title", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 562, 170, 575 ], "spans": [ { "bbox": [ 109, 562, 170, 575 ], "type": "text", "content": "1．设计目的", "score": 1.0 } ] } ] }, { "bbox": [ 86, 585, 503, 645 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 110, 587, 504, 597 ], "spans": [ { "bbox": [ 110, 587, 504, 597 ], "type": "text", "content": "Linux提供的模块机制能动态扩充linux功能而无需重新编译内核，已经广泛应用在linux", "score": 1.0 } ] }, { "bbox": [ 88, 602, 503, 613 ], "spans": [ { "bbox": [ 88, 602, 503, 613 ], "type": "text", "content": "内核的许多功能的实现中。在本实验中将学习模块的基本概念、原理及实现技术，然后利", "score": 1.0 } ] }, { "bbox": [ 89, 617, 503, 629 ], "spans": [ { "bbox": [ 89, 617, 503, 629 ], "type": "text", "content": "用内核模块编程访问进程的基本信息，从而加深对进程概念的理解、对模块编程技术的掌", "score": 1.0 } ] }, { "bbox": [ 88, 632, 108, 647 ], "spans": [ { "bbox": [ 88, 632, 108, 647 ], "type": "text", "content": "握。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 655, 170, 668 ], "type": "title", "angle": 0, "index": 20, "lines": [ { "bbox": [ 108, 655, 170, 669 ], "spans": [ { "bbox": [ 108, 655, 170, 669 ], "type": "text", "content": "2．内容要求", "score": 1.0 } ] } ] }, { "bbox": [ 86, 679, 503, 754 ], "type": "list", "angle": 0, "index": 24, "blocks": [ { "bbox": [ 86, 679, 503, 707 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 113, 678, 503, 692 ], "spans": [ { "bbox": [ 113, 678, 135, 692 ], "type": "text", "content": "（1）", "score": 1.0 }, { "bbox": [ 151, 679, 503, 692 ], "type": "text", "content": "设计一个模块，要求列出系统中所有内核线程的程序名、PID号、进程状态及", "score": 1.0 } ] }, { "bbox": [ 88, 695, 148, 708 ], "spans": [ { "bbox": [ 88, 695, 148, 708 ], "type": "text", "content": "进程优先级。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 710, 503, 737 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 113, 709, 505, 724 ], "spans": [ { "bbox": [ 113, 709, 505, 724 ], "type": "text", "content": "（2） 设计一个带参数的模块，其参数为某个进程的 PID号，该模块的功能是列出该", "score": 1.0 } ] }, { "bbox": [ 89, 726, 406, 737 ], "spans": [ { "bbox": [ 89, 726, 406, 737 ], "type": "text", "content": "进程的家族信息，包括父进程、兄弟进程和子进程的程序名、PID号。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 741, 483, 754 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 114, 741, 484, 754 ], "spans": [ { "bbox": [ 114, 741, 484, 754 ], "type": "text", "content": "（3） 请根据自身情况，进一步阅读分析程序中用到的相关内核函数的源码实现。", "score": 1.0 } ] } ] } ], "sub_type": "text" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 25 }, { "para_blocks": [ { "bbox": [ 107, 80, 227, 93 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 80, 226, 94 ], "spans": [ { "bbox": [ 109, 80, 226, 94 ], "type": "text", "content": "3. 学时安排（共 4 学时）", "score": 1.0 } ] } ] }, { "bbox": [ 107, 111, 175, 125 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 111, 175, 126 ], "spans": [ { "bbox": [ 108, 111, 175, 126 ], "type": "text", "content": "4． 开发平台", "score": 1.0 } ] } ] }, { "bbox": [ 129, 135, 309, 148 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 129, 134, 311, 150 ], "spans": [ { "bbox": [ 129, 134, 311, 150 ], "type": "text", "content": "Linux 环境，gcc，gdb，vim 或 gedit 等。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 170, 277, 187 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 114, 169, 278, 189 ], "spans": [ { "bbox": [ 114, 169, 278, 189 ], "type": "text", "content": "2.2 linux 内核模块简介", "score": 1.0 } ] } ] }, { "bbox": [ 114, 216, 223, 231 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 216, 223, 232 ], "spans": [ { "bbox": [ 114, 216, 223, 232 ], "type": "text", "content": "2.2.1 线程基本概念", "score": 1.0 } ] } ] }, { "bbox": [ 86, 241, 507, 393 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 242, 505, 253 ], "spans": [ { "bbox": [ 109, 242, 505, 253 ], "type": "text", "content": "Linux 内核是单体式结构，相对于微内核结构而言，其运行效率高，但系统的可维护性", "score": 1.0 } ] }, { "bbox": [ 89, 258, 505, 269 ], "spans": [ { "bbox": [ 89, 258, 505, 269 ], "type": "text", "content": "及可扩展性较差。为此，linux 提供了内核模块（module）机制，它不仅可以弥补单体式内", "score": 1.0 } ] }, { "bbox": [ 89, 273, 505, 284 ], "spans": [ { "bbox": [ 89, 273, 505, 284 ], "type": "text", "content": "核相对于微内核的一些不足，而且对系统性能没有影响。内核模块的全称是动态可加载内核", "score": 1.0 } ] }, { "bbox": [ 88, 287, 506, 301 ], "spans": [ { "bbox": [ 88, 287, 506, 301 ], "type": "text", "content": "模块（Loadable Kernel Module,KLM），简称为模块。模块是一个目标文件，能完成某种独立", "score": 1.0 } ] }, { "bbox": [ 89, 305, 505, 315 ], "spans": [ { "bbox": [ 89, 305, 505, 315 ], "type": "text", "content": "的功能，但其自身不是一个独立的进程，不能单独运行，可以动态载入内核，使其成为内核", "score": 1.0 } ] }, { "bbox": [ 89, 319, 505, 332 ], "spans": [ { "bbox": [ 89, 319, 505, 332 ], "type": "text", "content": "代码的一部分，与其他内核代码的地位完全相同。当不需要某模块功能时，可以动态卸载。", "score": 1.0 } ] }, { "bbox": [ 89, 335, 501, 347 ], "spans": [ { "bbox": [ 89, 335, 501, 347 ], "type": "text", "content": "实际上，linux 中大多数设备驱动程序或文件系统都以模块方式实现，因为它们数目繁多，", "score": 1.0 } ] }, { "bbox": [ 89, 350, 505, 363 ], "spans": [ { "bbox": [ 89, 350, 505, 363 ], "type": "text", "content": "体积庞大，不适合直接编译在内核中，而是通过模块机制，需要时临时加载。使用模块机制", "score": 1.0 } ] }, { "bbox": [ 89, 367, 504, 377 ], "spans": [ { "bbox": [ 89, 367, 504, 377 ], "type": "text", "content": "的另一个好处是，修改模块代码后只需重新编译和加载模块，不必重新编译内核和引导系统，", "score": 1.0 } ] }, { "bbox": [ 89, 382, 221, 393 ], "spans": [ { "bbox": [ 89, 382, 221, 393 ], "type": "text", "content": "降低了系统功能的更新难度。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 396, 506, 441 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 110, 396, 506, 411 ], "spans": [ { "bbox": [ 110, 396, 506, 411 ], "type": "text", "content": "一个模块通常由一组函数和数据结构组成，用来实现某种功能，如实现一种文件系统、", "score": 1.0 } ] }, { "bbox": [ 89, 412, 505, 425 ], "spans": [ { "bbox": [ 89, 412, 505, 425 ], "type": "text", "content": "一个驱动程序或其他内核上层的功能。模块自身不是一个独立的进程，当前进程运行是调用", "score": 1.0 } ] }, { "bbox": [ 89, 429, 389, 440 ], "spans": [ { "bbox": [ 89, 429, 389, 440 ], "type": "text", "content": "到模块代码时，可以认为该段代码就代表当前进程在核心态运行。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 450, 214, 465 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 450, 213, 465 ], "spans": [ { "bbox": [ 114, 450, 213, 465 ], "type": "text", "content": "2.2.2 内核符号表", "score": 1.0 } ] } ] }, { "bbox": [ 86, 474, 506, 518 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 110, 476, 505, 486 ], "spans": [ { "bbox": [ 110, 476, 505, 486 ], "type": "text", "content": "模块编程可以使用内核的一些全局变量和函数，内核符号表就是用来存放所有模块都可", "score": 1.0 } ] }, { "bbox": [ 89, 490, 506, 503 ], "spans": [ { "bbox": [ 89, 490, 506, 503 ], "type": "text", "content": "以访问的符号及相应地址的表，其存放位置在/proc/kallsyms 文件中，我们可以使用“cat", "score": 1.0 } ] }, { "bbox": [ 88, 507, 336, 518 ], "spans": [ { "bbox": [ 88, 507, 336, 518 ], "type": "text", "content": "/proc/kallsyms”命令查看当前环境下导出的内核符号。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 521, 505, 581 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 523, 505, 534 ], "spans": [ { "bbox": [ 110, 523, 505, 534 ], "type": "text", "content": "通常情况下，一个模块只需实现自己的功能，而无需导出任何符号；但如果其他模块需", "score": 1.0 } ] }, { "bbox": [ 89, 538, 505, 550 ], "spans": [ { "bbox": [ 89, 538, 505, 550 ], "type": "text", "content": "要调用这个模块的函数或数据结构时，该模块也可以导出符号。这样，其他模块可以使用由", "score": 1.0 } ] }, { "bbox": [ 90, 554, 504, 565 ], "spans": [ { "bbox": [ 90, 554, 504, 565 ], "type": "text", "content": "该模块导出的符号，利用现成的代码实现更加复杂的功能，这种技术也称作模块层叠技术，", "score": 1.0 } ] }, { "bbox": [ 89, 569, 284, 580 ], "spans": [ { "bbox": [ 89, 569, 284, 580 ], "type": "text", "content": "当前已经使用在很多主流的内核源代码中。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 583, 379, 597 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 584, 379, 597 ], "spans": [ { "bbox": [ 110, 584, 379, 597 ], "type": "text", "content": "如果一个模块需要向其他模块导出符号，可使用下面的宏：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 600, 256, 613 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 597, 257, 616 ], "spans": [ { "bbox": [ 108, 597, 257, 616 ], "type": "text", "content": "EXPORT_SYMBOL(symbol_name)；", "score": 1.0 } ] } ] }, { "bbox": [ 108, 616, 278, 629 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 108, 614, 278, 631 ], "spans": [ { "bbox": [ 108, 614, 278, 631 ], "type": "text", "content": "EXPORT_SYMOBL_GPL(symbol_name)；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 630, 506, 675 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 630, 506, 644 ], "spans": [ { "bbox": [ 109, 630, 506, 644 ], "type": "text", "content": "这两个宏均用于将给定的符号导出到模块外部。_GPL版本使得要导出的符号只能被GPL", "score": 1.0 } ] }, { "bbox": [ 89, 647, 505, 658 ], "spans": [ { "bbox": [ 89, 647, 505, 658 ], "type": "text", "content": "许可证下的模块使用。符号必须在模块文件的全局部分导出，不能在模块中的某个函数中导", "score": 1.0 } ] }, { "bbox": [ 88, 661, 107, 677 ], "spans": [ { "bbox": [ 88, 661, 107, 677 ], "type": "text", "content": "出。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 698, 259, 714 ], "type": "title", "angle": 0, "index": 15, "lines": [ { "bbox": [ 116, 697, 260, 714 ], "spans": [ { "bbox": [ 116, 697, 260, 714 ], "type": "text", "content": "2.3 内核模块编程基础", "score": 1.0 } ] } ] }, { "bbox": [ 87, 736, 506, 765 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 110, 736, 506, 749 ], "spans": [ { "bbox": [ 110, 736, 506, 749 ], "type": "text", "content": "我们以一个简单的“hello world”模块的实现为例，来说明内核模块的编写结构、编译", "score": 1.0 } ] }, { "bbox": [ 89, 753, 148, 764 ], "spans": [ { "bbox": [ 89, 753, 148, 764 ], "type": "text", "content": "及加载过程。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 26 }, { "para_blocks": [ { "bbox": [ 113, 79, 226, 93 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 115, 79, 226, 95 ], "spans": [ { "bbox": [ 115, 79, 226, 95 ], "type": "text", "content": "2.3.1 模块代码结构", "score": 1.0 } ] } ] }, { "bbox": [ 112, 104, 258, 116 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 104, 258, 118 ], "spans": [ { "bbox": [ 114, 104, 258, 118 ], "type": "text", "content": "“hello world”的示例代码如下：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 120, 309, 382 ], "blocks": [ { "bbox": [ 108, 120, 309, 382 ], "lines": [ { "bbox": [ 108, 120, 309, 382 ], "spans": [ { "bbox": [ 108, 120, 309, 382 ], "type": "text", "content": "1 #include \n2 #include \n3 #include \n4 \n5 static int hello_init(void) \n6 { \n7 " }, { "bbox": [ 108, 120, 309, 382 ], "type": "inline_equation", "content": "\\mathrm{printk}(\\mathrm{KERN\\_ALERT}\"hello,\\mathrm{world}\\backslash \\mathrm{n\"});" }, { "bbox": [ 108, 120, 309, 382 ], "type": "text", "content": " \n8 return 0; \n9 } \n10 static void hello_exit(void) \n11 { \n12 " }, { "bbox": [ 108, 120, 309, 382 ], "type": "inline_equation", "content": "\\mathrm{printk}(\\mathrm{KERN\\_ALERT}\"goodbye\\backslash n\")" }, { "bbox": [ 108, 120, 309, 382 ], "type": "text", "content": " \n13 } \n14 \n15 module_init(hello_init); \n16 module_exit(hello_exit); \n17 MODULE licenses(\"GPL\");" } ] } ], "index": 3, "angle": 0, "type": "code_body" } ], "index": 3, "sub_type": "algorithm" }, { "bbox": [ 86, 400, 505, 444 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 112, 401, 505, 412 ], "spans": [ { "bbox": [ 112, 401, 505, 412 ], "type": "text", "content": "上面的代码是一个内核模块的典型结构。该模块被载入内核时会向系统日志文件中写入", "score": 1.0 } ] }, { "bbox": [ 92, 414, 506, 429 ], "spans": [ { "bbox": [ 92, 414, 506, 429 ], "type": "text", "content": "“hello，world”；当被卸载时，也会向系统日志中写入“goodbye”。下面说明该模块代码的", "score": 1.0 } ] }, { "bbox": [ 88, 430, 138, 445 ], "spans": [ { "bbox": [ 88, 430, 138, 445 ], "type": "text", "content": "结构组成：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 447, 204, 459 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 446, 205, 461 ], "spans": [ { "bbox": [ 114, 446, 205, 461 ], "type": "text", "content": "（1） 头文件声明：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 462, 505, 507 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 462, 505, 476 ], "spans": [ { "bbox": [ 110, 462, 505, 476 ], "type": "text", "content": "第1、2 行是模块编程的必需头文件。module.h包含了大量加载模块所需要的函数和符", "score": 1.0 } ] }, { "bbox": [ 89, 478, 505, 491 ], "spans": [ { "bbox": [ 89, 478, 505, 491 ], "type": "text", "content": "号的定义；init.h 包含了模块初始化和清理函数的定义。如果模块在加载时允许用户传递参", "score": 1.0 } ] }, { "bbox": [ 88, 493, 295, 507 ], "spans": [ { "bbox": [ 88, 493, 295, 507 ], "type": "text", "content": "数，模块还应该包含 moduleparam.h 头文件。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 509, 214, 521 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 508, 215, 523 ], "spans": [ { "bbox": [ 114, 508, 215, 523 ], "type": "text", "content": "（2） 模块许可申明：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 524, 508, 631 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 110, 525, 506, 538 ], "spans": [ { "bbox": [ 110, 525, 506, 538 ], "type": "text", "content": "第 17 行是模块许可声明。Linux 内核从 2.4.10 版本内核开始，模块必须通过", "score": 1.0 } ] }, { "bbox": [ 88, 540, 506, 553 ], "spans": [ { "bbox": [ 88, 540, 506, 553 ], "type": "text", "content": "MODULE_LICENSE 宏声明此模块的许可证，否则在加载此模块时，会收到内核被污染 “kernel", "score": 1.0 } ] }, { "bbox": [ 88, 557, 509, 568 ], "spans": [ { "bbox": [ 88, 557, 509, 568 ], "type": "text", "content": "tainted” 的警告。从 linux/module.h 文件中可以看到，被内核接受的有意义的许可证有 “GPL”，", "score": 1.0 } ] }, { "bbox": [ 88, 572, 506, 584 ], "spans": [ { "bbox": [ 88, 572, 506, 584 ], "type": "text", "content": "“GPL v2”，“GPL and additional rights”，“Dual BSD/GPL”，“Dual MPL/GPL”，“Proprietary”，其中", "score": 1.0 } ] }, { "bbox": [ 90, 587, 506, 601 ], "spans": [ { "bbox": [ 90, 587, 506, 601 ], "type": "text", "content": "“GPL” 是指明这是 GNU General Public License 的任意版本，其他许可证大家可以查阅资料", "score": 1.0 } ] }, { "bbox": [ 88, 603, 505, 616 ], "spans": [ { "bbox": [ 88, 603, 505, 616 ], "type": "text", "content": "进一步了解。MODULE_LICENSE 宏声明可以写在模块的任何地方（但必须在函数外面），不", "score": 1.0 } ] }, { "bbox": [ 88, 618, 200, 631 ], "spans": [ { "bbox": [ 88, 618, 200, 631 ], "type": "text", "content": "过惯例是写在模块最后。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 634, 267, 646 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 634, 267, 648 ], "spans": [ { "bbox": [ 114, 634, 267, 648 ], "type": "text", "content": "（3） 初始化与清理函数的注册：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 649, 506, 756 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 111, 650, 505, 661 ], "spans": [ { "bbox": [ 111, 650, 505, 661 ], "type": "text", "content": "内核模块程序中没有 main函数，每个模块必须定义两个函数：一个函数用来初始化（示", "score": 1.0 } ] }, { "bbox": [ 89, 665, 506, 677 ], "spans": [ { "bbox": [ 89, 665, 506, 677 ], "type": "text", "content": "例第 5 行），主要完成模块注册和申请资源，该函数返回 0，表示初始化成功，其他值表示", "score": 1.0 } ] }, { "bbox": [ 89, 682, 506, 693 ], "spans": [ { "bbox": [ 89, 682, 506, 693 ], "type": "text", "content": "失败；另一个函数用来退出（示例第 10 行），主要完成注销和释放资源。Linux 调用宏", "score": 1.0 } ] }, { "bbox": [ 89, 698, 506, 708 ], "spans": [ { "bbox": [ 89, 698, 506, 708 ], "type": "text", "content": "module_init 和 module_exit 来注册这两个函数，如示例中第 15、16 两行代码，module_init", "score": 1.0 } ] }, { "bbox": [ 88, 712, 506, 724 ], "spans": [ { "bbox": [ 88, 712, 506, 724 ], "type": "text", "content": "宏标记的函数在加载模块时调用，module_exit 宏标记的函数在卸载模块时调用。需要注意", "score": 1.0 } ] }, { "bbox": [ 88, 726, 506, 741 ], "spans": [ { "bbox": [ 88, 726, 506, 741 ], "type": "text", "content": "的是，初始化与清理函数必须在宏 module_init和 module_exit使用前定义，否则会出现编译", "score": 1.0 } ] }, { "bbox": [ 88, 742, 118, 757 ], "spans": [ { "bbox": [ 88, 742, 118, 757 ], "type": "text", "content": "错误。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 27 }, { "para_blocks": [ { "type": "code", "bbox": [ 108, 72, 220, 164 ], "blocks": [ { "bbox": [ 108, 72, 220, 164 ], "lines": [ { "bbox": [ 108, 72, 220, 164 ], "spans": [ { "bbox": [ 108, 72, 220, 164 ], "type": "text", "content": "初始化函数通常定义为： \nstatic int __init init_func(v{ //初始化代码} module_init(init_func);" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 86, 166, 505, 210 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 166, 505, 179 ], "spans": [ { "bbox": [ 110, 166, 505, 179 ], "type": "text", "content": "一般情况下，初始化函数应当申明为 static，以便它们不会在特定文件之外可见。如果", "score": 1.0 } ] }, { "bbox": [ 89, 182, 505, 195 ], "spans": [ { "bbox": [ 89, 182, 505, 195 ], "type": "text", "content": "该函数只是在初始化使用一次，可在声明语句中加__init标识，则模块在加载后会丢弃这个", "score": 1.0 } ] }, { "bbox": [ 89, 198, 232, 211 ], "spans": [ { "bbox": [ 89, 198, 232, 211 ], "type": "text", "content": "初始化函数，释放其内存空间。", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 212, 214, 304 ], "blocks": [ { "bbox": [ 108, 212, 214, 304 ], "lines": [ { "bbox": [ 108, 212, 214, 304 ], "spans": [ { "bbox": [ 108, 212, 214, 304 ], "type": "text", "content": "清理函数通常定义为： \nstatic void __exit exit_fu{//清理代码} \nmodule_exitexit_func);" } ] } ], "index": 3, "angle": 0, "type": "code_body" } ], "index": 3, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 86, 306, 504, 335 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 306, 505, 319 ], "spans": [ { "bbox": [ 109, 306, 505, 319 ], "type": "text", "content": "清理函数没有返回值，因此被声明为 void。声明语句中的__exit的含义与初始化函数中", "score": 1.0 } ] }, { "bbox": [ 88, 322, 207, 336 ], "spans": [ { "bbox": [ 88, 322, 207, 336 ], "type": "text", "content": "的__init 类似，不再重述。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 338, 399, 350 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 337, 399, 351 ], "spans": [ { "bbox": [ 110, 337, 399, 351 ], "type": "text", "content": "一个基本的内核模块只要包含上述三个部分就可以正常工作了。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 354, 224, 366 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 113, 352, 227, 370 ], "spans": [ { "bbox": [ 113, 352, 227, 370 ], "type": "text", "content": "（4） printk()函数说明：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 369, 505, 412 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 110, 370, 505, 381 ], "spans": [ { "bbox": [ 110, 370, 505, 381 ], "type": "text", "content": "大家可能已经发现在代码第 3行还有一个头文件“头文件:#include<linux/init.h>#include<linux/module.h必选许可声明MODULE_LICENSE("Dual BSD/GPL")必选加载函数static int __init hello_init(void)必选卸载函数static void __exit hello_exit(void)必选模块参数moduleparam(name,type,perm)可选模块导出符号EXPORT_SYMBOL(符号名)可选模块作者等信息MODULE_AUTHOR("作者名")可选", "image_path": "8c5696582781d2d9cd88646275c972203e093f0e15447f6f98aec1b46b5fa5ad.jpg" } ] } ], "index": 14, "angle": 0, "type": "table_body" } ], "index": 14 }, { "bbox": [ 113, 707, 238, 721 ], "type": "title", "angle": 0, "index": 15, "lines": [ { "bbox": [ 115, 707, 238, 722 ], "spans": [ { "bbox": [ 115, 707, 238, 722 ], "type": "text", "content": "2.3.2 模块编译和加载", "score": 1.0 } ] } ] }, { "bbox": [ 108, 739, 250, 751 ], "type": "title", "angle": 0, "index": 16, "lines": [ { "bbox": [ 110, 739, 251, 752 ], "spans": [ { "bbox": [ 110, 739, 251, 752 ], "type": "text", "content": "1. 模块编译的 Makefile 文件：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 28 }, { "para_blocks": [ { "bbox": [ 86, 72, 505, 132 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 73, 506, 85 ], "spans": [ { "bbox": [ 109, 73, 506, 85 ], "type": "text", "content": "在linux2.6 及之后的内核中，模块的编译需要配置过的内核源代码，否则无法进行模块", "score": 1.0 } ] }, { "bbox": [ 89, 89, 505, 100 ], "spans": [ { "bbox": [ 89, 89, 505, 100 ], "type": "text", "content": "的编译工作；编译、链接后生成的内核模块后缀为.ko；编译过程首先会都内核源目录下读", "score": 1.0 } ] }, { "bbox": [ 88, 104, 505, 117 ], "spans": [ { "bbox": [ 88, 104, 505, 117 ], "type": "text", "content": "取顶层的 Makefile 文件（注意第一个字母“M”需要大写），然后返回模块源代码所在的目", "score": 1.0 } ] }, { "bbox": [ 89, 120, 148, 132 ], "spans": [ { "bbox": [ 89, 120, 148, 132 ], "type": "text", "content": "录继续编译。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 135, 505, 163 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 136, 505, 148 ], "spans": [ { "bbox": [ 109, 136, 505, 148 ], "type": "text", "content": "在使用make命令编译模块代码时，应先书写 Makefile 文件，且应放在模块源代码文件", "score": 1.0 } ] }, { "bbox": [ 88, 151, 424, 163 ], "spans": [ { "bbox": [ 88, 151, 424, 163 ], "type": "text", "content": "所在目录中。针对上面的“hello world”模块，编写的一个简单 Makefile：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 166, 503, 272 ], "type": "list", "angle": 0, "index": 10, "blocks": [ { "bbox": [ 86, 166, 377, 180 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 86, 165, 376, 182 ], "spans": [ { "bbox": [ 86, 165, 177, 182 ], "type": "text", "content": "1 obj-m :=hello.o", "score": 1.0 }, { "bbox": [ 236, 165, 376, 180 ], "type": "text", "content": "//生成的模块名称是：hello.ko", "score": 1.0 } ] } ] }, { "bbox": [ 87, 182, 299, 195 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 86, 181, 300, 197 ], "spans": [ { "bbox": [ 86, 181, 300, 197 ], "type": "text", "content": "2 KDIR :=/lib/modules/$(shell uname -r)/build", "score": 1.0 } ] } ] }, { "bbox": [ 87, 197, 313, 211 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 85, 195, 314, 213 ], "spans": [ { "bbox": [ 85, 195, 196, 213 ], "type": "text", "content": "3 PWD :=$(shell pwd)", "score": 1.0 }, { "bbox": [ 223, 196, 314, 211 ], "type": "text", "content": "// PWD 是当前目录", "score": 1.0 } ] } ] }, { "bbox": [ 88, 214, 144, 226 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 86, 212, 145, 227 ], "spans": [ { "bbox": [ 86, 212, 145, 227 ], "type": "text", "content": "4 default:", "score": 1.0 } ] } ] }, { "bbox": [ 87, 228, 503, 242 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 88, 228, 505, 243 ], "spans": [ { "bbox": [ 88, 230, 96, 243 ], "type": "text", "content": "5", "score": 1.0 }, { "bbox": [ 130, 228, 201, 242 ], "type": "text", "content": "make -C $(KDIR)", "score": 1.0 }, { "bbox": [ 201, 230, 222, 241 ], "type": "inline_equation", "content": "M = S", "score": 0.52 }, { "bbox": [ 223, 228, 505, 242 ], "type": "text", "content": "(PWD) modules // -C 指定内核源码目录，M 指定模块源码目录", "score": 1.0 } ] } ] }, { "bbox": [ 88, 245, 136, 256 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 88, 244, 139, 258 ], "spans": [ { "bbox": [ 88, 245, 103, 256 ], "type": "text", "content": "6", "score": 1.0 }, { "bbox": [ 105, 244, 139, 258 ], "type": "text", "content": "clean:", "score": 1.0 } ] } ] }, { "bbox": [ 88, 260, 275, 272 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 88, 259, 276, 275 ], "spans": [ { "bbox": [ 88, 261, 96, 273 ], "type": "text", "content": "7", "score": 1.0 }, { "bbox": [ 130, 259, 276, 275 ], "type": "text", "content": "make -C $(KDIR) M=$(PWD) clean", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 275, 505, 304 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 276, 505, 287 ], "spans": [ { "bbox": [ 110, 276, 505, 287 ], "type": "text", "content": "其中：KDIR 是内核源码目录，该目录通过当前运行内核使用的模块目录中的build符号", "score": 1.0 } ] }, { "bbox": [ 88, 290, 506, 305 ], "spans": [ { "bbox": [ 88, 290, 325, 305 ], "type": "text", "content": "链接指定。或者直接给出源码目录也可以，如：KDIR :", "score": 1.0 }, { "bbox": [ 325, 293, 333, 302 ], "type": "inline_equation", "content": ": =", "score": 0.6 }, { "bbox": [ 333, 290, 506, 305 ], "type": "text", "content": "/usr/src/linux-headers-4.4.0-36-generic.", "score": 1.0 } ] } ] }, { "bbox": [ 108, 306, 488, 319 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 307, 489, 320 ], "spans": [ { "bbox": [ 109, 307, 489, 320 ], "type": "text", "content": "需要注意的是，在第 5 行和第 7 行的“make”之前应该是“tab”键，而不是空格。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 330, 334, 343 ], "type": "title", "angle": 0, "index": 13, "lines": [ { "bbox": [ 108, 329, 336, 344 ], "spans": [ { "bbox": [ 108, 329, 336, 344 ], "type": "text", "content": "2. 由多个文件构成的内核模块的 Makefile 文件：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 353, 504, 366 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 111, 354, 504, 366 ], "spans": [ { "bbox": [ 111, 354, 504, 366 ], "type": "text", "content": "当模块的功能较多时，把模块的源代码分成几个文件是一个明智的选择，如下面的示例：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 370, 389, 461 ], "blocks": [ { "bbox": [ 108, 370, 389, 461 ], "lines": [ { "bbox": [ 108, 370, 389, 461 ], "spans": [ { "bbox": [ 108, 370, 389, 461 ], "type": "text", "content": "hello1print.c: \n#include \n#include \n#include \nMODULE_LICENSE(\"GPL\"); \nvoid hello2print(void); //来源于第二个.c文件：hello2print.c" } ] } ], "index": 15, "angle": 0, "type": "code_body" } ], "index": 15, "sub_type": "code", "guess_lang": "cpp" }, { "type": "code", "bbox": [ 108, 477, 289, 757 ], "blocks": [ { "bbox": [ 108, 477, 289, 757 ], "lines": [ { "bbox": [ 108, 477, 289, 757 ], "spans": [ { "bbox": [ 108, 477, 289, 757 ], "type": "text", "content": "static int __init hello_init(void) \n{ printf(KERN_ALERT\"hello,world\\n\"); hello2print(); return 0; \n} \nstatic void _exit hello_exit(void) \n{ printf(KERN_ALERT\"goodbye\\n\"); \n} \nmodule_init(hello_init); module_exit(hello_exit); \nhello2print.c \n#include \"linux/kernel.h\" \nvoid hello2print(void)" } ] } ], "index": 16, "angle": 0, "type": "code_body" } ], "index": 16, "sub_type": "code", "guess_lang": "c" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 29 }, { "para_blocks": [ { "type": "code", "bbox": [ 107, 73, 315, 117 ], "blocks": [ { "bbox": [ 107, 73, 315, 117 ], "lines": [ { "bbox": [ 107, 73, 315, 117 ], "spans": [ { "bbox": [ 107, 73, 315, 117 ], "type": "text", "content": "{ printk(KERN_ALERT\"this is hello2 print\\n\"); }" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 108, 135, 413, 163 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 135, 314, 148 ], "spans": [ { "bbox": [ 109, 135, 233, 148 ], "type": "text", "content": "则 Makefile 相应的行改为：", "score": 1.0 }, { "bbox": [ 245, 136, 314, 148 ], "type": "text", "content": "obj-m :=hello.o", "score": 1.0 } ] }, { "bbox": [ 246, 151, 413, 164 ], "spans": [ { "bbox": [ 246, 151, 413, 164 ], "type": "text", "content": "hello-objs :=hello1print.o hello2print.o", "score": 1.0 } ] } ] }, { "bbox": [ 86, 166, 503, 194 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 164, 506, 180 ], "spans": [ { "bbox": [ 109, 164, 506, 180 ], "type": "text", "content": "其中含有 module_init(hello_init);module_exit(hello_exit);这两个宏的.o 模块应放在开始。", "score": 1.0 } ] }, { "bbox": [ 88, 182, 221, 195 ], "spans": [ { "bbox": [ 88, 182, 221, 195 ], "type": "text", "content": "完整的Makefile 文件内容为：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 197, 503, 319 ], "type": "list", "angle": 0, "index": 12, "blocks": [ { "bbox": [ 86, 197, 386, 211 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 86, 196, 387, 213 ], "spans": [ { "bbox": [ 86, 197, 183, 213 ], "type": "text", "content": "1 obj-m :=hello2.o", "score": 1.0 }, { "bbox": [ 241, 196, 387, 212 ], "type": "text", "content": "//生成的模块名称是：hello2.ko", "score": 1.0 } ] } ] }, { "bbox": [ 87, 213, 282, 226 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 86, 213, 283, 228 ], "spans": [ { "bbox": [ 86, 213, 283, 228 ], "type": "text", "content": "2 hello2-objs :=hello1print.o hello2print.o", "score": 1.0 } ] } ] }, { "bbox": [ 88, 229, 299, 242 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 86, 227, 300, 243 ], "spans": [ { "bbox": [ 86, 227, 300, 243 ], "type": "text", "content": "3 KDIR :=/lib/modules/$(shell uname -r)/build", "score": 1.0 } ] } ] }, { "bbox": [ 88, 244, 312, 257 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 86, 242, 314, 260 ], "spans": [ { "bbox": [ 86, 242, 136, 260 ], "type": "text", "content": "4 PWD :", "score": 1.0 }, { "bbox": [ 136, 245, 148, 256 ], "type": "inline_equation", "content": ": = \\$ 5", "score": 0.53 }, { "bbox": [ 148, 242, 196, 260 ], "type": "text", "content": "(shell pwd)", "score": 1.0 }, { "bbox": [ 223, 243, 314, 258 ], "type": "text", "content": "// PWD 是当前目录", "score": 1.0 } ] } ] }, { "bbox": [ 88, 260, 143, 271 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 88, 259, 145, 274 ], "spans": [ { "bbox": [ 88, 259, 145, 274 ], "type": "text", "content": "5 default:", "score": 1.0 } ] } ] }, { "bbox": [ 88, 275, 503, 288 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 88, 275, 504, 289 ], "spans": [ { "bbox": [ 88, 276, 97, 289 ], "type": "text", "content": "6", "score": 1.0 }, { "bbox": [ 130, 275, 201, 289 ], "type": "text", "content": "make -C $(KDIR)", "score": 1.0 }, { "bbox": [ 201, 276, 223, 288 ], "type": "inline_equation", "content": "M = S", "score": 0.59 }, { "bbox": [ 223, 275, 504, 289 ], "type": "text", "content": "(PWD) modules // -C 指定内核源码目录，M 指定模块源码目录", "score": 1.0 } ] } ] }, { "bbox": [ 88, 292, 136, 302 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 86, 290, 139, 306 ], "spans": [ { "bbox": [ 86, 290, 139, 306 ], "type": "text", "content": "7 clean:", "score": 1.0 } ] } ] }, { "bbox": [ 88, 306, 275, 319 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 88, 306, 276, 321 ], "spans": [ { "bbox": [ 88, 307, 97, 320 ], "type": "text", "content": "8", "score": 1.0 }, { "bbox": [ 130, 306, 276, 321 ], "type": "text", "content": "make -C $(KDIR) M=$(PWD) clean", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 322, 504, 365 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 110, 322, 505, 334 ], "spans": [ { "bbox": [ 110, 322, 505, 334 ], "type": "text", "content": "注意：1）第 1 行和第 2 行中的“hello2”必须名字相同，表示模块 hello2 的目标文件", "score": 1.0 } ] }, { "bbox": [ 88, 337, 502, 351 ], "spans": [ { "bbox": [ 88, 337, 502, 351 ], "type": "text", "content": "来源于 hello1print.o 和 hello2print.o。2）在第 6 行和第 8 行的“make”之前应该是“tab”", "score": 1.0 } ] }, { "bbox": [ 88, 354, 169, 366 ], "spans": [ { "bbox": [ 88, 354, 169, 366 ], "type": "text", "content": "键，而不是空格。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 376, 193, 389 ], "type": "title", "angle": 0, "index": 14, "lines": [ { "bbox": [ 107, 376, 194, 390 ], "spans": [ { "bbox": [ 107, 376, 194, 390 ], "type": "text", "content": "3. 相关操作命令：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 400, 356, 412 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 401, 357, 414 ], "spans": [ { "bbox": [ 110, 401, 357, 414 ], "type": "text", "content": "以下命令除 make 命令外，其他都应以 root 用户执行：", "score": 1.0 } ] } ] }, { "bbox": [ 111, 416, 239, 428 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 113, 414, 240, 430 ], "spans": [ { "bbox": [ 113, 414, 240, 430 ], "type": "text", "content": "（1） 模块编译命令 make：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 431, 192, 443 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 430, 193, 445 ], "spans": [ { "bbox": [ 109, 430, 193, 445 ], "type": "text", "content": "命令格式：$make", "score": 1.0 } ] } ] }, { "bbox": [ 86, 447, 504, 475 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 446, 506, 460 ], "spans": [ { "bbox": [ 109, 446, 506, 460 ], "type": "text", "content": "不带参数的make命令将默认当前目录下名为makefile或者名为Makefile的文件为描述", "score": 1.0 } ] }, { "bbox": [ 86, 460, 119, 478 ], "spans": [ { "bbox": [ 86, 460, 119, 478 ], "type": "text", "content": "文件。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 478, 308, 490 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 113, 476, 309, 493 ], "spans": [ { "bbox": [ 113, 476, 309, 493 ], "type": "text", "content": "（2） 加载模块命令 insmod 或 modprobe：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 493, 504, 522 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 108, 494, 505, 506 ], "spans": [ { "bbox": [ 108, 494, 505, 506 ], "type": "text", "content": "insmod 命令把需要载入的模块以目标代码的形式加载到内核中，将自动调用", "score": 1.0 } ] }, { "bbox": [ 88, 510, 211, 521 ], "spans": [ { "bbox": [ 88, 510, 211, 521 ], "type": "text", "content": "init_module 宏。其格式为：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 525, 280, 538 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 108, 524, 281, 539 ], "spans": [ { "bbox": [ 108, 524, 281, 539 ], "type": "text", "content": "# insmod [filename] [module options...]", "score": 1.0 } ] } ] }, { "bbox": [ 86, 540, 504, 568 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 109, 540, 506, 554 ], "spans": [ { "bbox": [ 109, 540, 506, 554 ], "type": "text", "content": "Modprobe 命令的功能与 insmod 一样，区别在于 modprobe 能够处理 module 载入的", "score": 1.0 } ] }, { "bbox": [ 88, 555, 189, 570 ], "spans": [ { "bbox": [ 88, 555, 189, 570 ], "type": "text", "content": "相依问题，其格式为：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 572, 421, 584 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 107, 571, 423, 587 ], "spans": [ { "bbox": [ 107, 571, 423, 587 ], "type": "text", "content": "# modprobe [module options...] [modulename] [module parameters...]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 587, 333, 599 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 108, 586, 334, 602 ], "spans": [ { "bbox": [ 108, 586, 334, 602 ], "type": "text", "content": "如本示例中加载模块的命令为：# insmod hello.ko", "score": 1.0 } ] } ] }, { "bbox": [ 113, 602, 238, 614 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 114, 602, 239, 617 ], "spans": [ { "bbox": [ 114, 602, 239, 617 ], "type": "text", "content": "（3） 查看模块命令 lsmod：", "score": 1.0 } ] } ] }, { "bbox": [ 120, 618, 504, 645 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 123, 618, 505, 631 ], "spans": [ { "bbox": [ 123, 618, 505, 631 ], "type": "text", "content": "列出当前所有已载入系统的模块信息，包括模块名、大小、其他模块的引用计数等", "score": 1.0 } ] }, { "bbox": [ 123, 634, 242, 646 ], "spans": [ { "bbox": [ 123, 634, 242, 646 ], "type": "text", "content": "信息。命令格式：# lsmod", "score": 1.0 } ] } ] }, { "bbox": [ 107, 649, 433, 661 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 108, 649, 434, 664 ], "spans": [ { "bbox": [ 108, 649, 434, 664 ], "type": "text", "content": "通常会配合 grep 来查看指定模块是否已经加载：# lsmod | grep 模块名", "score": 1.0 } ] } ] }, { "bbox": [ 113, 666, 248, 677 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 114, 665, 249, 679 ], "spans": [ { "bbox": [ 114, 665, 249, 679 ], "type": "text", "content": "（5） 卸载模块命令 rmmod：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 681, 293, 692 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 110, 681, 294, 693 ], "spans": [ { "bbox": [ 110, 681, 294, 693 ], "type": "text", "content": "卸载已经载入内核的指定模块，格式为：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 696, 186, 708 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 107, 696, 188, 709 ], "spans": [ { "bbox": [ 107, 696, 188, 709 ], "type": "text", "content": "# rmmod 模块名", "score": 1.0 } ] } ] }, { "bbox": [ 108, 719, 210, 731 ], "type": "title", "angle": 0, "index": 31, "lines": [ { "bbox": [ 109, 720, 210, 732 ], "spans": [ { "bbox": [ 109, 720, 210, 732 ], "type": "text", "content": "4. 带参数的模块编程", "score": 1.0 } ] } ] }, { "bbox": [ 107, 742, 504, 755 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 110, 743, 505, 756 ], "spans": [ { "bbox": [ 110, 743, 505, 756 ], "type": "text", "content": "有时候用户需要向模块传递一些参数，如使用模块机制实现设备驱动程序时，用户可能", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 30 }, { "para_blocks": [ { "bbox": [ 86, 72, 294, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 89, 73, 295, 86 ], "spans": [ { "bbox": [ 89, 73, 295, 86 ], "type": "text", "content": "希望在不同条件下让设备在不同状态下工作。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 89, 183, 100 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 113, 87, 185, 103 ], "spans": [ { "bbox": [ 113, 87, 185, 103 ], "type": "text", "content": "（1） 头文件：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 104, 424, 116 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 102, 427, 120 ], "spans": [ { "bbox": [ 109, 102, 427, 120 ], "type": "text", "content": "模块要带参数，则头文件必须包括：#include 。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 120, 232, 133 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 112, 116, 233, 137 ], "spans": [ { "bbox": [ 112, 116, 233, 137 ], "type": "text", "content": "（2） module_param ()宏", "score": 1.0 } ] } ] }, { "bbox": [ 86, 135, 509, 163 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 108, 135, 510, 148 ], "spans": [ { "bbox": [ 108, 135, 510, 148 ], "type": "text", "content": "module_param ()宏的功能是在加载模块时或者模块加载以后传递参数给模块，其格式为：", "score": 1.0 } ] }, { "bbox": [ 88, 152, 236, 164 ], "spans": [ { "bbox": [ 88, 152, 236, 164 ], "type": "text", "content": "module_param(name,type,perm);", "score": 1.0 } ] } ] }, { "bbox": [ 108, 166, 243, 178 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 166, 243, 179 ], "spans": [ { "bbox": [ 109, 166, 243, 179 ], "type": "text", "content": "其中：name:模块参数的名称", "score": 1.0 } ] } ] }, { "bbox": [ 139, 182, 264, 195 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 140, 182, 265, 195 ], "spans": [ { "bbox": [ 140, 182, 265, 195 ], "type": "text", "content": "type: 模块参数的数据类型", "score": 1.0 } ] } ] }, { "bbox": [ 139, 197, 268, 210 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 140, 198, 268, 211 ], "spans": [ { "bbox": [ 140, 198, 268, 211 ], "type": "text", "content": "perm: 模块参数的访问权限", "score": 1.0 } ] } ] }, { "bbox": [ 108, 212, 304, 226 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 110, 213, 305, 225 ], "spans": [ { "bbox": [ 110, 213, 305, 225 ], "type": "text", "content": "更加详细的内容请大家参考其他资料自学。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 228, 509, 272 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 108, 227, 509, 243 ], "spans": [ { "bbox": [ 108, 227, 509, 243 ], "type": "text", "content": "程序中首先将所有需要获取参数值的变量声明为全局变量；然后使用宏 module_param ()", "score": 1.0 } ] }, { "bbox": [ 89, 244, 505, 257 ], "spans": [ { "bbox": [ 89, 244, 505, 257 ], "type": "text", "content": "对所有参数进行说明，这个宏定义应当放在任何函数之外，典型地是出现在源文件的前面，", "score": 1.0 } ] }, { "bbox": [ 89, 261, 248, 272 ], "spans": [ { "bbox": [ 89, 261, 248, 272 ], "type": "text", "content": "如下面示例程序中的第8、9两行。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 275, 505, 304 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 276, 505, 287 ], "spans": [ { "bbox": [ 110, 276, 505, 287 ], "type": "text", "content": "然后在加载模块的命令行后面跟上参数值即可。注意，必须明确指出哪一个变量的值是", "score": 1.0 } ] }, { "bbox": [ 89, 291, 440, 302 ], "spans": [ { "bbox": [ 89, 291, 440, 302 ], "type": "text", "content": "多少，否则系统不能判断。如对本示例，可用如下命令加载模块并传递参数：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 126, 307, 318, 320 ], "blocks": [ { "bbox": [ 126, 307, 318, 320 ], "lines": [ { "bbox": [ 126, 307, 318, 320 ], "spans": [ { "bbox": [ 126, 307, 318, 320 ], "type": "text", "content": "insmod module_parako who " }, { "bbox": [ 126, 307, 318, 320 ], "type": "inline_equation", "content": "\\equiv" }, { "bbox": [ 126, 307, 318, 320 ], "type": "text", "content": " zwh times " }, { "bbox": [ 126, 307, 318, 320 ], "type": "inline_equation", "content": "= 4" } ] } ], "index": 12, "angle": 0, "type": "code_body" } ], "index": 12, "sub_type": "algorithm" }, { "bbox": [ 121, 338, 170, 350 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 121, 337, 171, 352 ], "spans": [ { "bbox": [ 121, 337, 171, 352 ], "type": "text", "content": "示例程序：", "score": 1.0 } ] } ] }, { "bbox": [ 122, 354, 334, 693 ], "type": "list", "angle": 0, "index": 36, "blocks": [ { "bbox": [ 122, 354, 224, 365 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 121, 354, 226, 367 ], "spans": [ { "bbox": [ 121, 354, 226, 367 ], "type": "text", "content": "1 #include", "score": 1.0 } ] } ] }, { "bbox": [ 122, 370, 243, 380 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 122, 370, 243, 382 ], "spans": [ { "bbox": [ 122, 370, 243, 382 ], "type": "text", "content": "2 #include", "score": 1.0 } ] } ] }, { "bbox": [ 122, 386, 238, 396 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 121, 385, 238, 398 ], "spans": [ { "bbox": [ 121, 385, 238, 398 ], "type": "text", "content": "3 #include", "score": 1.0 } ] } ] }, { "bbox": [ 122, 401, 273, 412 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 121, 399, 274, 414 ], "spans": [ { "bbox": [ 121, 399, 274, 414 ], "type": "text", "content": "4 #include ", "score": 1.0 } ] } ] }, { "bbox": [ 122, 417, 244, 428 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 121, 415, 245, 431 ], "spans": [ { "bbox": [ 121, 415, 245, 431 ], "type": "text", "content": "5 MODULE_LICENSE(\"GPL\");", "score": 1.0 } ] } ] }, { "bbox": [ 122, 432, 270, 443 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 121, 431, 271, 444 ], "spans": [ { "bbox": [ 121, 431, 271, 444 ], "type": "text", "content": "6 static char *who; //参数申明", "score": 1.0 } ] } ] }, { "bbox": [ 122, 448, 205, 459 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 121, 446, 207, 461 ], "spans": [ { "bbox": [ 121, 446, 207, 461 ], "type": "text", "content": "7 static int times;", "score": 1.0 } ] } ] }, { "bbox": [ 122, 463, 334, 476 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 120, 462, 336, 477 ], "spans": [ { "bbox": [ 120, 462, 336, 477 ], "type": "text", "content": "8 module_param(who,char,0644); //参数说明", "score": 1.0 } ] } ] }, { "bbox": [ 122, 479, 268, 491 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 121, 478, 269, 493 ], "spans": [ { "bbox": [ 121, 478, 269, 493 ], "type": "text", "content": "9 module_param(times,int,0644);", "score": 1.0 } ] } ] }, { "bbox": [ 122, 494, 282, 507 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 122, 492, 284, 509 ], "spans": [ { "bbox": [ 122, 494, 137, 507 ], "type": "text", "content": "10", "score": 1.0 }, { "bbox": [ 148, 492, 284, 509 ], "type": "text", "content": "static int __init hello_init(void)", "score": 1.0 } ] } ] }, { "bbox": [ 122, 510, 157, 521 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 121, 509, 161, 524 ], "spans": [ { "bbox": [ 121, 509, 139, 523 ], "type": "text", "content": "11", "score": 1.0 }, { "bbox": [ 133, 509, 161, 524 ], "type": "text", "content": "{", "score": 1.0 } ] } ] }, { "bbox": [ 122, 526, 193, 536 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 121, 523, 196, 540 ], "spans": [ { "bbox": [ 121, 524, 136, 540 ], "type": "text", "content": "12", "score": 1.0 }, { "bbox": [ 170, 523, 196, 540 ], "type": "text", "content": "int i;", "score": 1.0 } ] } ] }, { "bbox": [ 122, 541, 270, 553 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 121, 539, 271, 555 ], "spans": [ { "bbox": [ 121, 540, 136, 554 ], "type": "text", "content": "13", "score": 1.0 }, { "bbox": [ 171, 539, 271, 555 ], "type": "text", "content": "for(i = 1;i <= times;i++)", "score": 1.0 } ] } ] }, { "bbox": [ 122, 556, 291, 569 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 121, 555, 292, 571 ], "spans": [ { "bbox": [ 121, 555, 136, 569 ], "type": "text", "content": "14", "score": 1.0 }, { "bbox": [ 171, 555, 292, 571 ], "type": "text", "content": "printk(\"%d %s!\\n\",i,who);", "score": 1.0 } ] } ] }, { "bbox": [ 122, 573, 211, 583 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 121, 571, 213, 586 ], "spans": [ { "bbox": [ 121, 571, 136, 586 ], "type": "text", "content": "15", "score": 1.0 }, { "bbox": [ 171, 571, 213, 586 ], "type": "text", "content": "return 0;", "score": 1.0 } ] } ] }, { "bbox": [ 122, 587, 157, 599 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 121, 587, 160, 602 ], "spans": [ { "bbox": [ 121, 587, 140, 601 ], "type": "text", "content": "16", "score": 1.0 }, { "bbox": [ 133, 587, 160, 602 ], "type": "text", "content": "}", "score": 1.0 } ] } ] }, { "bbox": [ 122, 603, 293, 615 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 122, 602, 294, 618 ], "spans": [ { "bbox": [ 122, 602, 138, 616 ], "type": "text", "content": "17", "score": 1.0 }, { "bbox": [ 149, 602, 294, 618 ], "type": "text", "content": "static void __exit hello_exit(void)", "score": 1.0 } ] } ] }, { "bbox": [ 122, 619, 157, 630 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 121, 618, 161, 634 ], "spans": [ { "bbox": [ 121, 618, 140, 633 ], "type": "text", "content": "18", "score": 1.0 }, { "bbox": [ 133, 618, 161, 634 ], "type": "text", "content": "{", "score": 1.0 } ] } ] }, { "bbox": [ 122, 634, 303, 647 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 121, 633, 305, 649 ], "spans": [ { "bbox": [ 121, 634, 136, 648 ], "type": "text", "content": "19", "score": 1.0 }, { "bbox": [ 171, 633, 305, 649 ], "type": "text", "content": "printk(\"Goodbye,%s!\\n\",who);", "score": 1.0 } ] } ] }, { "bbox": [ 122, 650, 157, 661 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 120, 648, 161, 665 ], "spans": [ { "bbox": [ 120, 648, 161, 665 ], "type": "text", "content": "20 }", "score": 1.0 } ] } ] }, { "bbox": [ 122, 666, 254, 678 ], "type": "text", "angle": 0, "index": 34, "lines": [ { "bbox": [ 121, 665, 255, 681 ], "spans": [ { "bbox": [ 121, 665, 138, 679 ], "type": "text", "content": "21", "score": 1.0 }, { "bbox": [ 143, 665, 255, 681 ], "type": "text", "content": "module_init(hello_init);", "score": 1.0 } ] } ] }, { "bbox": [ 122, 682, 257, 693 ], "type": "text", "angle": 0, "index": 35, "lines": [ { "bbox": [ 122, 680, 258, 697 ], "spans": [ { "bbox": [ 122, 681, 137, 694 ], "type": "text", "content": "22", "score": 1.0 }, { "bbox": [ 148, 680, 258, 697 ], "type": "text", "content": "module_exit(hello_exit);", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 115, 731, 202, 748 ], "type": "title", "angle": 0, "index": 37, "lines": [ { "bbox": [ 114, 731, 204, 750 ], "spans": [ { "bbox": [ 114, 731, 204, 750 ], "type": "text", "content": "2.4 实验指南", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 31 }, { "para_blocks": [ { "bbox": [ 113, 79, 295, 94 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 114, 79, 295, 95 ], "spans": [ { "bbox": [ 114, 79, 295, 95 ], "type": "text", "content": "2.4.1 linux 内核链表结构及操作", "score": 1.0 } ] } ] }, { "bbox": [ 86, 104, 505, 149 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 104, 505, 116 ], "spans": [ { "bbox": [ 109, 104, 505, 116 ], "type": "text", "content": "链表是linux内核中最简单、最常用的一种数据结构。Linux内核对链表的实现方式与众", "score": 1.0 } ] }, { "bbox": [ 89, 121, 505, 132 ], "spans": [ { "bbox": [ 89, 121, 505, 132 ], "type": "text", "content": "不同，它给出了一种抽象链表定义，实际使用中可将其嵌入到其他数据结构中，从而演化出", "score": 1.0 } ] }, { "bbox": [ 89, 136, 200, 148 ], "spans": [ { "bbox": [ 89, 136, 200, 148 ], "type": "text", "content": "所需要的复杂数据结构。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 158, 186, 171 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 158, 187, 172 ], "spans": [ { "bbox": [ 109, 158, 187, 172 ], "type": "text", "content": "1. 链表的定义：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 107, 182, 257, 242 ], "blocks": [ { "bbox": [ 107, 182, 257, 242 ], "lines": [ { "bbox": [ 107, 182, 257, 242 ], "spans": [ { "bbox": [ 107, 182, 257, 242 ], "type": "text", "content": "Linux中链表的定义为： \nstruct list_head{structlist_head \\*next,\\*prev;1" } ] } ], "index": 4, "angle": 0, "type": "code_body" } ], "index": 4, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 96, 243, 493, 273 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 113, 245, 492, 256 ], "spans": [ { "bbox": [ 113, 245, 492, 256 ], "type": "text", "content": "这个不含数据域的链表，可以嵌入到任何结构中，形成结构复杂的链表，之后就以", "score": 1.0 } ] }, { "bbox": [ 98, 260, 478, 273 ], "spans": [ { "bbox": [ 98, 260, 478, 273 ], "type": "text", "content": "struct list_head为基本对象，进行链表的插入、删除、合并、遍历等各种操作。如：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 107, 275, 217, 335 ], "blocks": [ { "bbox": [ 107, 275, 217, 335 ], "lines": [ { "bbox": [ 107, 275, 217, 335 ], "spans": [ { "bbox": [ 107, 275, 217, 335 ], "type": "text", "content": "struct numlist {\n int num;\n struct list_head list;\n};" } ] } ], "index": 6, "angle": 0, "type": "code_body" } ], "index": 6, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 107, 345, 182, 359 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 108, 346, 181, 359 ], "spans": [ { "bbox": [ 108, 346, 181, 359 ], "type": "text", "content": "2. 链表的操作", "score": 1.0 } ] } ] }, { "bbox": [ 113, 369, 286, 382 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 367, 287, 385 ], "spans": [ { "bbox": [ 114, 367, 287, 385 ], "type": "text", "content": "（1）list_for_each()宏和 list_entry()宏：", "score": 1.0 } ] } ] }, { "bbox": [ 96, 384, 499, 428 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 110, 385, 500, 396 ], "spans": [ { "bbox": [ 110, 385, 500, 396 ], "type": "text", "content": "Linux 内核为抽象链表定义了若干操作，如申明及初始化链表、插入节点、删除节点、", "score": 1.0 } ] }, { "bbox": [ 100, 401, 499, 412 ], "spans": [ { "bbox": [ 100, 401, 499, 412 ], "type": "text", "content": "合并链表、遍历链表等。本实验只涉及读取内核已有链表，所以这里只介绍链表遍历操作，", "score": 1.0 } ] }, { "bbox": [ 99, 416, 424, 428 ], "spans": [ { "bbox": [ 99, 416, 424, 428 ], "type": "text", "content": "感兴趣的同学可以查看/usr/src/linux4.4.19/include/linux/list.h 文件学习。", "score": 1.0 } ] } ] }, { "bbox": [ 117, 431, 253, 444 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 119, 432, 253, 444 ], "spans": [ { "bbox": [ 119, 432, 253, 444 ], "type": "text", "content": "list.h中定义了遍历链表的宏：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 117, 447, 367, 538 ], "blocks": [ { "bbox": [ 117, 447, 367, 538 ], "lines": [ { "bbox": [ 117, 447, 367, 538 ], "spans": [ { "bbox": [ 117, 447, 367, 538 ], "type": "text", "content": "/* list_for_each - iterate over a list\n* @pos: the &struct list_head to use as a loop cursor.\n* @head: the head for your list.\n*/\n#define list_for_each(pos, head) \\\nfor (pos = (head) -> next; pos != (head); pos = pos->next)" } ] } ], "index": 11, "angle": 0, "type": "code_body" } ], "index": 11, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 117, 539, 445, 554 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 119, 539, 446, 554 ], "spans": [ { "bbox": [ 119, 539, 446, 554 ], "type": "text", "content": "这个宏仅仅是找到一个个节点在链表中的偏移位置pos，如图2-1 所示：", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 123, 559, 262, 650 ], "blocks": [ { "bbox": [ 123, 559, 262, 650 ], "lines": [ { "bbox": [ 123, 559, 262, 650 ], "spans": [ { "bbox": [ 123, 559, 262, 650 ], "type": "image", "image_path": "16e0b5d1d8b750f96f2f0ca9fca4f70df1d53cdfcec3a346d21b668739c668be.jpg" } ] } ], "index": 13, "angle": 0, "type": "image_body" }, { "bbox": [ 143, 661, 251, 673 ], "lines": [ { "bbox": [ 145, 661, 250, 674 ], "spans": [ { "bbox": [ 145, 661, 250, 674 ], "type": "text", "content": "图2-1 list_for_each()宏", "score": 1.0 } ] } ], "index": 14, "angle": 0, "type": "image_caption" } ], "index": 13 }, { "type": "image", "bbox": [ 310, 560, 431, 650 ], "blocks": [ { "bbox": [ 310, 560, 431, 650 ], "lines": [ { "bbox": [ 310, 560, 431, 650 ], "spans": [ { "bbox": [ 310, 560, 431, 650 ], "type": "image", "image_path": "92220b9c147f7c8f052989864f727a61513e9b59b96a8a33fc4e65df31d5a3ae.jpg" } ] } ], "index": 15, "angle": 0, "type": "image_body" }, { "bbox": [ 327, 661, 422, 673 ], "lines": [ { "bbox": [ 329, 660, 423, 675 ], "spans": [ { "bbox": [ 329, 660, 423, 675 ], "type": "text", "content": "图2-2 list_entry()宏", "score": 1.0 } ] } ], "index": 16, "angle": 0, "type": "image_caption" } ], "index": 15 }, { "bbox": [ 96, 681, 505, 709 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 120, 681, 505, 693 ], "spans": [ { "bbox": [ 120, 681, 505, 693 ], "type": "text", "content": "问题是，如何通过 pos 获得节点的起始地址，以便引用节点中的其他域？在 list.h 中", "score": 1.0 } ] }, { "bbox": [ 99, 696, 196, 710 ], "spans": [ { "bbox": [ 99, 696, 196, 710 ], "type": "text", "content": "定义了 list_entry()宏：", "score": 1.0 } ] } ] }, { "bbox": [ 117, 712, 296, 725 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 119, 710, 296, 727 ], "spans": [ { "bbox": [ 119, 710, 296, 727 ], "type": "text", "content": "/* list_entry - get the struct for this entry", "score": 1.0 } ] } ] }, { "bbox": [ 123, 728, 352, 756 ], "type": "list", "angle": 0, "index": 21, "blocks": [ { "bbox": [ 123, 728, 299, 740 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 123, 725, 300, 744 ], "spans": [ { "bbox": [ 123, 725, 300, 744 ], "type": "text", "content": "* @ptr: the &struct list_head pointer.", "score": 1.0 } ] } ] }, { "bbox": [ 123, 743, 352, 756 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 123, 741, 355, 759 ], "spans": [ { "bbox": [ 123, 741, 355, 759 ], "type": "text", "content": "* @type: the type of the struct this is embedded in.", "score": 1.0 } ] } ] } ], "sub_type": "text" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 32 }, { "para_blocks": [ { "bbox": [ 116, 73, 381, 86 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 124, 73, 381, 87 ], "spans": [ { "bbox": [ 124, 73, 381, 87 ], "type": "text", "content": "* @member: the name of the list_head within the struct.", "score": 1.0 } ] } ] }, { "bbox": [ 123, 89, 136, 100 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 124, 89, 138, 104 ], "spans": [ { "bbox": [ 124, 89, 138, 104 ], "type": "text", "content": "*/", "score": 1.0 } ] } ] }, { "bbox": [ 118, 105, 286, 133 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 119, 104, 286, 117 ], "spans": [ { "bbox": [ 119, 104, 286, 117 ], "type": "text", "content": "#define list_entry(ptr, type, member) \\", "score": 1.0 } ] }, { "bbox": [ 130, 120, 271, 134 ], "spans": [ { "bbox": [ 130, 120, 271, 134 ], "type": "text", "content": "container_of(ptr, type, member)", "score": 1.0 } ] } ] }, { "bbox": [ 117, 135, 446, 148 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 119, 133, 448, 150 ], "spans": [ { "bbox": [ 119, 133, 448, 150 ], "type": "text", "content": "其中宏 container_of()定义在/usr/src/linux4.4.19/include/linux/kernel.h 中：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 118, 151, 364, 195 ], "blocks": [ { "bbox": [ 118, 151, 364, 195 ], "lines": [ { "bbox": [ 118, 151, 364, 195 ], "spans": [ { "bbox": [ 118, 151, 364, 195 ], "type": "text", "content": "define container_of(ptr, type, member) {{const typeof((type*)0)->member)\\*mptr = (ptr);" }, { "bbox": [ 118, 151, 364, 195 ], "type": "inline_equation", "content": "(type\\*)(char" }, { "bbox": [ 118, 151, 364, 195 ], "type": "text", "content": "_mptr - offsetof(type,member));}}" } ] } ], "index": 5, "angle": 0, "type": "code_body" } ], "index": 5, "sub_type": "algorithm" }, { "bbox": [ 96, 197, 505, 242 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 120, 198, 505, 211 ], "spans": [ { "bbox": [ 120, 198, 505, 211 ], "type": "text", "content": "该宏的功能是计算返回包含 ptr 指向的成员所在的 type 类型数据结构的指针，如图", "score": 1.0 } ] }, { "bbox": [ 99, 213, 504, 225 ], "spans": [ { "bbox": [ 99, 213, 504, 225 ], "type": "text", "content": "2-2 所示。其实现思路是：计算 type 结构体成员 member 在结构体中的偏移量，然后用", "score": 1.0 } ] }, { "bbox": [ 98, 229, 367, 242 ], "spans": [ { "bbox": [ 98, 229, 367, 242 ], "type": "text", "content": "ptr 的值减去这个偏移量，就得出 type 数据结构的首地址。", "score": 1.0 } ] } ] }, { "bbox": [ 118, 244, 240, 257 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 120, 245, 240, 257 ], "spans": [ { "bbox": [ 120, 245, 240, 257 ], "type": "text", "content": "例如前面定义的链表结构：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 117, 260, 238, 319 ], "blocks": [ { "bbox": [ 117, 260, 238, 319 ], "lines": [ { "bbox": [ 117, 260, 238, 319 ], "spans": [ { "bbox": [ 117, 260, 238, 319 ], "type": "text", "content": "struct numlist {\n int num;\n struct list_head list;\n};" } ] } ], "index": 8, "angle": 0, "type": "code_body" } ], "index": 8, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 118, 322, 282, 334 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 120, 322, 283, 335 ], "spans": [ { "bbox": [ 120, 322, 283, 335 ], "type": "text", "content": "可通过如下方式遍历链表的各节点：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 117, 338, 356, 444 ], "blocks": [ { "bbox": [ 117, 338, 356, 444 ], "lines": [ { "bbox": [ 117, 338, 356, 444 ], "spans": [ { "bbox": [ 117, 338, 356, 444 ], "type": "text", "content": "struct numlist numhead //链表头节点\nstruct list_head *pos;\nstruct numlist *p;\nlist_for_each(pos, &numhead.list) {\n p=list_entry(pos, struct numlist, list);\n //下面可以对p指向的numlist节点进行相关操作\n}" } ] } ], "index": 10, "angle": 0, "type": "code_body" } ], "index": 10, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 114, 447, 240, 475 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 445, 240, 461 ], "spans": [ { "bbox": [ 114, 445, 240, 461 ], "type": "text", "content": "（2）list_for_each_entry()宏", "score": 1.0 } ] }, { "bbox": [ 114, 461, 139, 475 ], "spans": [ { "bbox": [ 114, 461, 139, 475 ], "type": "text", "content": "/**", "score": 1.0 } ] } ] }, { "bbox": [ 123, 478, 396, 552 ], "type": "list", "angle": 0, "index": 17, "blocks": [ { "bbox": [ 123, 478, 389, 491 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 123, 476, 390, 494 ], "spans": [ { "bbox": [ 123, 476, 232, 494 ], "type": "text", "content": "* list_for_each_entry -", "score": 1.0 }, { "bbox": [ 265, 476, 390, 493 ], "type": "text", "content": "iterate over list of given type", "score": 1.0 } ] } ] }, { "bbox": [ 124, 494, 346, 507 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 122, 491, 347, 511 ], "spans": [ { "bbox": [ 122, 491, 164, 511 ], "type": "text", "content": "* @pos:", "score": 1.0 }, { "bbox": [ 201, 493, 347, 508 ], "type": "text", "content": "the type * to use as a loop cursor.", "score": 1.0 } ] } ] }, { "bbox": [ 124, 509, 295, 522 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 123, 507, 296, 524 ], "spans": [ { "bbox": [ 123, 507, 170, 524 ], "type": "text", "content": "* @head:", "score": 1.0 }, { "bbox": [ 201, 509, 296, 523 ], "type": "text", "content": "the head for your list.", "score": 1.0 } ] } ] }, { "bbox": [ 124, 525, 396, 538 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 123, 523, 398, 539 ], "spans": [ { "bbox": [ 123, 523, 185, 539 ], "type": "text", "content": "* @member:", "score": 1.0 }, { "bbox": [ 206, 525, 398, 539 ], "type": "text", "content": "the name of the list_struct within the struct.", "score": 1.0 } ] } ] }, { "bbox": [ 124, 541, 136, 552 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 124, 540, 138, 555 ], "spans": [ { "bbox": [ 124, 540, 138, 555 ], "type": "text", "content": "*/", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "type": "code", "bbox": [ 118, 556, 473, 616 ], "blocks": [ { "bbox": [ 118, 556, 473, 616 ], "lines": [ { "bbox": [ 118, 556, 473, 616 ], "spans": [ { "bbox": [ 118, 556, 473, 616 ], "type": "text", "content": "define list_for_each_entry(pos, head, member) \nfor (pos = list_entry((head) -> next, sizeof(*pos), member); \n prefetch(pos -> member.next), &pos -> member != (head); \n pos = list_entry(pos -> member.next, sizeof(*pos), member))" } ] } ], "index": 18, "angle": 0, "type": "code_body" } ], "index": 18, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 86, 618, 505, 661 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 112, 618, 506, 632 ], "spans": [ { "bbox": [ 112, 618, 506, 632 ], "type": "text", "content": "该宏实际上是一个 for 循环，利用传入的 pos 作为循环变量，从表头 head 开始，逐", "score": 1.0 } ] }, { "bbox": [ 88, 633, 506, 647 ], "spans": [ { "bbox": [ 88, 633, 506, 647 ], "type": "text", "content": "项向后（next 方向）移动 pos，直至又回head。prefetch() 可以不考虑，用于预取以提高遍", "score": 1.0 } ] }, { "bbox": [ 88, 648, 129, 663 ], "spans": [ { "bbox": [ 88, 648, 129, 663 ], "type": "text", "content": "历速度。", "score": 1.0 } ] } ] }, { "bbox": [ 119, 672, 348, 686 ], "type": "title", "angle": 0, "index": 20, "lines": [ { "bbox": [ 121, 671, 349, 687 ], "spans": [ { "bbox": [ 121, 671, 349, 687 ], "type": "text", "content": "2.4.2 进程的 task_struct 结构及家族关系", "score": 1.0 } ] } ] }, { "bbox": [ 86, 696, 505, 724 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 109, 695, 506, 710 ], "spans": [ { "bbox": [ 109, 695, 506, 710 ], "type": "text", "content": "Linux 进程描述符 task_struct 结构定义在/usr/src/linux4.4.19/include/linux/sched.h 中，包", "score": 1.0 } ] }, { "bbox": [ 89, 712, 458, 724 ], "spans": [ { "bbox": [ 89, 712, 458, 724 ], "type": "text", "content": "含众多的成员项，部分与本实验相关的成员项有：（相关含义自行查阅资料学习）", "score": 1.0 } ] } ] }, { "bbox": [ 120, 728, 264, 740 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 121, 726, 264, 742 ], "spans": [ { "bbox": [ 121, 726, 227, 742 ], "type": "text", "content": "#define TASK_RUNNING", "score": 1.0 }, { "bbox": [ 257, 729, 264, 740 ], "type": "text", "content": "0", "score": 1.0 } ] } ] }, { "bbox": [ 121, 743, 264, 756 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 122, 744, 265, 757 ], "spans": [ { "bbox": [ 122, 744, 265, 757 ], "type": "text", "content": "#define TASK_INTERRUPTIBLE 1", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 33 }, { "para_blocks": [ { "type": "code", "bbox": [ 116, 72, 456, 491 ], "blocks": [ { "bbox": [ 116, 72, 456, 491 ], "lines": [ { "bbox": [ 116, 72, 456, 491 ], "spans": [ { "bbox": [ 116, 72, 456, 491 ], "type": "text", "content": "define TASK_UNINTERRUPTIBLE 2\n#define _TASK_STOPPED 4\n#define _TASK tracerED 8\n/* in tsk->exit_state */\n#define EXITDead 16\n#define EXIT_ZOMBIE 32\n/* in tsk->state again */\n#define TASK_DEAD 64\n#define TASK_WAKEKILL 128\n#define TASK_WAKING 256\nstruct task_struct {\n volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */\n void *stack;\n int prio, static_prio, normal_prio;\n unsigned int policy;\n struct list_head tasks; /*线程组长链表，是节点*/\n struct mm_struct *mm, *active_mm;\n pid_t pid;\n pid_t tgid;\n struct task_struct __rcu *real_parent; /* real parent process */\n struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */\n struct list_head children; /* list of my children */\n struct list_head sibling; /* linkage in my parent's children list */\n cptime_t utime, stime, utimescaled, stimescaled;\n char comm[TASKCOMM_LEN]; /* executable name excluding path */\n};" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 86, 493, 505, 584 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 493, 505, 506 ], "spans": [ { "bbox": [ 110, 493, 505, 506 ], "type": "text", "content": "Linux 的进程和轻量级进程/线程均有相应的 task_struct 结构和 PID 号，而 POSIX 要求同", "score": 1.0 } ] }, { "bbox": [ 88, 508, 506, 523 ], "spans": [ { "bbox": [ 88, 508, 506, 523 ], "type": "text", "content": "一组线程有统一的 PID，为此 linux 引入了 tgid（thread group identifer），tgid 实际上是线程", "score": 1.0 } ] }, { "bbox": [ 89, 525, 505, 538 ], "spans": [ { "bbox": [ 89, 525, 505, 538 ], "type": "text", "content": "组第一个线程的pid值，该线程称为线程组长。对于普通进程，其 pid与 tgid是相同的。此", "score": 1.0 } ] }, { "bbox": [ 89, 540, 505, 553 ], "spans": [ { "bbox": [ 89, 540, 505, 553 ], "type": "text", "content": "外，linux系统的进程包含一种特殊的类型——内核线程（kernel thread），完成内核的一些特", "score": 1.0 } ] }, { "bbox": [ 89, 555, 506, 570 ], "spans": [ { "bbox": [ 89, 555, 506, 570 ], "type": "text", "content": "定任务，并始终在核心态运行，没有用户态地址空间，其 task_struct 结构的 mm 成员项为", "score": 1.0 } ] }, { "bbox": [ 88, 572, 182, 585 ], "spans": [ { "bbox": [ 88, 572, 182, 585 ], "type": "text", "content": "NULL，如交换进程。", "score": 1.0 } ] } ] }, { "bbox": [ 96, 587, 505, 630 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 120, 587, 505, 600 ], "spans": [ { "bbox": [ 120, 587, 505, 600 ], "type": "text", "content": "实验内容（1）可以利用内核的线程组长链表实现，每个线程组长通过 task_struct 结", "score": 1.0 } ] }, { "bbox": [ 98, 602, 506, 618 ], "spans": [ { "bbox": [ 98, 602, 506, 618 ], "type": "text", "content": "构的 tasks 成员加入该链表。Linux 内核提供了宏 for_each_process()访问该链表中的每个进", "score": 1.0 } ] }, { "bbox": [ 97, 617, 117, 633 ], "spans": [ { "bbox": [ 97, 617, 117, 633 ], "type": "text", "content": "程：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 634, 359, 663 ], "blocks": [ { "bbox": [ 108, 634, 359, 663 ], "lines": [ { "bbox": [ 108, 634, 359, 663 ], "spans": [ { "bbox": [ 108, 634, 359, 663 ], "type": "text", "content": "define for_each_process(p) \\ \nfor (p = &init_task; (p = next_task(p)) != &init_task; )" } ] } ], "index": 4, "angle": 0, "type": "code_body" } ], "index": 4, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 117, 665, 379, 678 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 119, 664, 380, 680 ], "spans": [ { "bbox": [ 119, 664, 380, 680 ], "type": "text", "content": "宏 for_each_process 定义在/include/linux/sched.h 文件中。", "score": 1.0 } ] } ] }, { "bbox": [ 96, 680, 506, 756 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 120, 681, 506, 693 ], "spans": [ { "bbox": [ 120, 681, 506, 693 ], "type": "text", "content": "实验内容（2）需要了解 linux 进程家族的组织情况。所以的进程都是 PID 为 1 的 init", "score": 1.0 } ] }, { "bbox": [ 99, 697, 506, 709 ], "spans": [ { "bbox": [ 99, 697, 506, 709 ], "type": "text", "content": "进程的后代，内核在系统启动的最后阶段创建init进程，并由其完成后续启动工作。系统", "score": 1.0 } ] }, { "bbox": [ 99, 712, 506, 724 ], "spans": [ { "bbox": [ 99, 712, 506, 724 ], "type": "text", "content": "中的每个进程必有一个父进程，相应的，每个进程也可以拥有零个或多个子进程。父进程", "score": 1.0 } ] }, { "bbox": [ 104, 726, 507, 742 ], "spans": [ { "bbox": [ 104, 726, 507, 742 ], "type": "text", "content": "（task_struct 中的 parent 成员）相同的所有进程称为兄弟进程，由 task_struct 中的 sibling", "score": 1.0 } ] }, { "bbox": [ 99, 743, 395, 756 ], "spans": [ { "bbox": [ 99, 743, 395, 756 ], "type": "text", "content": "成员链接成父进程的 children链表，它们间的关系如图2-3所示：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 34 }, { "para_blocks": [ { "type": "image", "bbox": [ 127, 71, 442, 196 ], "blocks": [ { "bbox": [ 127, 71, 442, 196 ], "lines": [ { "bbox": [ 127, 71, 442, 196 ], "spans": [ { "bbox": [ 127, 71, 442, 196 ], "type": "image", "image_path": "c01a80ba569bbf26b8b3f732e9be35aaab91f0d1ae7fddc0b837200d4da3422f.jpg" } ] } ], "index": 1, "angle": 0, "type": "image_body" }, { "bbox": [ 239, 208, 324, 220 ], "lines": [ { "bbox": [ 242, 209, 324, 220 ], "spans": [ { "bbox": [ 242, 209, 324, 220 ], "type": "text", "content": "图2-3 进程家族关系", "score": 1.0 } ] } ], "index": 2, "angle": 0, "type": "image_caption" } ], "index": 1 }, { "bbox": [ 96, 228, 505, 274 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 119, 227, 505, 243 ], "spans": [ { "bbox": [ 119, 227, 505, 243 ], "type": "text", "content": "对子进程链表和兄弟进程链表的访问，都可以通过宏 list_for_each()和 list_entry()以及", "score": 1.0 } ] }, { "bbox": [ 98, 244, 505, 257 ], "spans": [ { "bbox": [ 98, 244, 505, 257 ], "type": "text", "content": "list_for_each_entry()来实现。对于指定的 pid，可以通过函数 pid_task()和 find_vpid()（或者", "score": 1.0 } ] }, { "bbox": [ 98, 260, 499, 273 ], "spans": [ { "bbox": [ 98, 260, 499, 273 ], "type": "text", "content": "find_get_pid()）配合使用找到其相应的 task_atruct 结构，位于 linux/kernel/pid.c 文件中：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 116, 291, 418, 631 ], "blocks": [ { "bbox": [ 116, 291, 418, 631 ], "lines": [ { "bbox": [ 116, 291, 418, 631 ], "spans": [ { "bbox": [ 116, 291, 418, 631 ], "type": "text", "content": "struct task_struct *result = NULL;\nif (pid) {\n struct hlist_node *first;\n first = rcu_dereference_check(pid->tasks[type].first, rcu_read_lock_held() || lockdep_tasklist_lock_is_held());\n if (first)\n result = hlist_entry(first, struct task_struct, pid[(type).node);\n} return result;\n}\nstruct pid *find_vpid(int nr) {\n return find.pid_ns(nr, current->nsproxy->pid_ns);\n}\nstruct pid *find_get.pid(pid_t nr) {\n struct pid *pid;\n pid = get.pid找到了pid(nr));\n rcu_read_unlock();\n return pid;\n}" } ] } ], "index": 4, "angle": 0, "type": "code_body" } ], "index": 4, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 166, 667, 437, 687 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 166, 665, 438, 690 ], "spans": [ { "bbox": [ 166, 665, 228, 690 ], "type": "text", "content": "实验三", "score": 1.0 }, { "bbox": [ 236, 666, 438, 690 ], "type": "text", "content": "linux 设备驱动程序开发", "score": 1.0 } ] } ] }, { "bbox": [ 114, 714, 280, 731 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 114, 714, 281, 732 ], "spans": [ { "bbox": [ 114, 714, 281, 732 ], "type": "text", "content": "3.1 设计目的和内容要求", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 35 }, { "para_blocks": [ { "bbox": [ 108, 80, 170, 93 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 110, 80, 170, 94 ], "spans": [ { "bbox": [ 110, 80, 170, 94 ], "type": "text", "content": "1．设计目的", "score": 1.0 } ] } ] }, { "bbox": [ 86, 104, 505, 163 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 104, 503, 116 ], "spans": [ { "bbox": [ 109, 104, 503, 116 ], "type": "text", "content": "Linux驱动程序占了内核代码的一半以上，开发设计驱动程序是 linux内核编程的一项很", "score": 1.0 } ] }, { "bbox": [ 89, 119, 502, 132 ], "spans": [ { "bbox": [ 89, 119, 502, 132 ], "type": "text", "content": "重要的工作。通过本次实验，学习者应了解 linux 的设备管理机制及驱动程序的组织结构；", "score": 1.0 } ] }, { "bbox": [ 89, 136, 503, 147 ], "spans": [ { "bbox": [ 89, 136, 503, 147 ], "type": "text", "content": "掌握linux设备驱动程序的编写流程及加载方法，为从事具体的硬件设备驱动程序开发打下", "score": 1.0 } ] }, { "bbox": [ 88, 150, 117, 163 ], "spans": [ { "bbox": [ 88, 150, 117, 163 ], "type": "text", "content": "基础。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 174, 170, 187 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 173, 171, 188 ], "spans": [ { "bbox": [ 108, 173, 171, 188 ], "type": "text", "content": "2．内容要求", "score": 1.0 } ] } ] }, { "bbox": [ 86, 197, 505, 288 ], "type": "list", "angle": 0, "index": 8, "blocks": [ { "bbox": [ 86, 197, 505, 241 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 104, 198, 505, 210 ], "spans": [ { "bbox": [ 104, 198, 505, 210 ], "type": "text", "content": "（1） 编写一个字符设备驱动程序，要求实现对该字符设备的打开、读、写、I/O 控制和", "score": 1.0 } ] }, { "bbox": [ 89, 213, 505, 225 ], "spans": [ { "bbox": [ 89, 213, 505, 225 ], "type": "text", "content": "关闭5 个基本操作。为了避免牵涉到汇编语言，这个字符设备并非一个真实的字符设备，而", "score": 1.0 } ] }, { "bbox": [ 89, 229, 359, 241 ], "spans": [ { "bbox": [ 89, 229, 359, 241 ], "type": "text", "content": "是用一段内存空间来模拟的。以模块方式加载该驱动程序。", "score": 1.0 } ] } ] }, { "bbox": [ 101, 244, 404, 257 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 103, 243, 405, 258 ], "spans": [ { "bbox": [ 103, 243, 405, 258 ], "type": "text", "content": "（2） 编写一个应用程序，测试（1）中实现的驱动程序的正确性。", "score": 1.0 } ] } ] }, { "bbox": [ 102, 260, 358, 272 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 104, 260, 358, 273 ], "spans": [ { "bbox": [ 104, 260, 358, 273 ], "type": "text", "content": "（3） 有兴趣的同学还可以编写一个块设备的驱动程序。", "score": 1.0 } ] } ] }, { "bbox": [ 102, 275, 467, 288 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 105, 276, 468, 288 ], "spans": [ { "bbox": [ 105, 276, 468, 288 ], "type": "text", "content": "（4）请根据自身情况，进一步阅读分析程序中用到的相关内核函数的源码实现。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 314, 227, 327 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 314, 226, 327 ], "spans": [ { "bbox": [ 109, 314, 226, 327 ], "type": "text", "content": "3. 学时安排（共 6学时）", "score": 1.0 } ] } ] }, { "bbox": [ 107, 345, 174, 358 ], "type": "title", "angle": 0, "index": 10, "lines": [ { "bbox": [ 108, 344, 175, 359 ], "spans": [ { "bbox": [ 108, 344, 175, 359 ], "type": "text", "content": "4． 开发平台", "score": 1.0 } ] } ] }, { "bbox": [ 129, 369, 309, 382 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 129, 368, 311, 384 ], "spans": [ { "bbox": [ 129, 368, 311, 384 ], "type": "text", "content": "Linux 环境，gcc，gdb，vim 或 gedit 等。", "score": 1.0 } ] } ] }, { "bbox": [ 103, 404, 267, 421 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 102, 403, 267, 423 ], "spans": [ { "bbox": [ 102, 403, 267, 423 ], "type": "text", "content": "3.2 linux 设备管理概述", "score": 1.0 } ] } ] }, { "bbox": [ 113, 450, 239, 465 ], "type": "title", "angle": 0, "index": 13, "lines": [ { "bbox": [ 114, 450, 238, 465 ], "spans": [ { "bbox": [ 114, 450, 238, 465 ], "type": "text", "content": "3.2.1 设备文件的概念", "score": 1.0 } ] } ] }, { "bbox": [ 86, 475, 504, 518 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 476, 503, 487 ], "spans": [ { "bbox": [ 109, 476, 503, 487 ], "type": "text", "content": "Linux沿用了Unix的设备管理思想，将所有设备看成是一类特殊文件，即为每个设备建", "score": 1.0 } ] }, { "bbox": [ 88, 490, 499, 503 ], "spans": [ { "bbox": [ 88, 490, 499, 503 ], "type": "text", "content": "立一个设备文件，一般保存在/dev目录下，如/dev/hda1标识第一个硬盘的第一个逻辑分区。", "score": 1.0 } ] }, { "bbox": [ 88, 506, 236, 518 ], "spans": [ { "bbox": [ 88, 506, 236, 518 ], "type": "text", "content": "Linux将系统中的设备分成三类：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 521, 504, 597 ], "type": "list", "angle": 0, "index": 18, "blocks": [ { "bbox": [ 107, 521, 504, 550 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 520, 504, 535 ], "spans": [ { "bbox": [ 110, 520, 125, 535 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.79 }, { "bbox": [ 132, 522, 504, 534 ], "type": "text", "content": "块设备：一次 I/O 操作是固定大小的数据块，可随机存取，其设备文件的属性字", "score": 1.0 } ] }, { "bbox": [ 127, 537, 234, 550 ], "spans": [ { "bbox": [ 127, 537, 234, 550 ], "type": "text", "content": "段中以“b”进行标识；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 552, 504, 581 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 110, 551, 504, 566 ], "spans": [ { "bbox": [ 110, 551, 125, 566 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.84 }, { "bbox": [ 126, 551, 504, 566 ], "type": "text", "content": "字符设备：只能按字节访问的设备，一次 I/O操作存取数据量不固定，只能顺序存", "score": 1.0 } ] }, { "bbox": [ 128, 568, 348, 581 ], "spans": [ { "bbox": [ 128, 568, 348, 581 ], "type": "text", "content": "取，其设备文件的属性字段中以“c”进行标识；", "score": 1.0 } ] } ] }, { "bbox": [ 108, 583, 376, 597 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 110, 582, 376, 597 ], "spans": [ { "bbox": [ 110, 582, 125, 597 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.82 }, { "bbox": [ 126, 583, 376, 597 ], "type": "text", "content": "网络设备：网卡是特殊处理的，没有对应的设备文件。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 113, 607, 226, 621 ], "type": "title", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 606, 226, 622 ], "spans": [ { "bbox": [ 114, 606, 226, 622 ], "type": "text", "content": "3.2.2 设备号的概念", "score": 1.0 } ] } ] }, { "bbox": [ 108, 638, 190, 651 ], "type": "title", "angle": 0, "index": 20, "lines": [ { "bbox": [ 110, 640, 191, 651 ], "spans": [ { "bbox": [ 110, 640, 191, 651 ], "type": "text", "content": "1．什么是设备号", "score": 1.0 } ] } ] }, { "bbox": [ 86, 661, 504, 690 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 111, 663, 503, 674 ], "spans": [ { "bbox": [ 111, 663, 503, 674 ], "type": "text", "content": "与普通文件一样，每个设备文件都有文件名和一个唯一的索引节点，在索引节点中记", "score": 1.0 } ] }, { "bbox": [ 88, 677, 389, 690 ], "spans": [ { "bbox": [ 88, 677, 389, 690 ], "type": "text", "content": "录了与特定设备建立连接所需的信息，其中最主要的三个信息是：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 693, 458, 736 ], "type": "list", "angle": 0, "index": 25, "blocks": [ { "bbox": [ 107, 693, 296, 705 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 110, 692, 298, 707 ], "spans": [ { "bbox": [ 110, 692, 125, 707 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.83 }, { "bbox": [ 126, 692, 298, 707 ], "type": "text", "content": "类型：表明是字符设备还是块设备；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 708, 396, 721 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 110, 708, 396, 723 ], "spans": [ { "bbox": [ 110, 708, 125, 722 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.86 }, { "bbox": [ 126, 708, 396, 723 ], "type": "text", "content": "主设备号：主设备号相同的设备，由同一个驱动程序控制；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 724, 458, 736 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 110, 724, 460, 738 ], "spans": [ { "bbox": [ 110, 724, 125, 738 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.86 }, { "bbox": [ 126, 724, 460, 738 ], "type": "text", "content": "次设备号：说明该设备是同类设备中的第几个，即表示具体的某个设备。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 740, 295, 752 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 109, 739, 295, 752 ], "spans": [ { "bbox": [ 109, 739, 295, 752 ], "type": "text", "content": "如查看/dev目录，可看到如下一些信息：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 36 }, { "para_blocks": [ { "type": "image", "bbox": [ 108, 71, 437, 117 ], "blocks": [ { "bbox": [ 108, 71, 437, 117 ], "lines": [ { "bbox": [ 108, 71, 437, 117 ], "spans": [ { "bbox": [ 108, 71, 437, 117 ], "type": "image", "image_path": "d24110f75720da97ed981ac4b0fa7b47e58905bf9cb7bcedd48d8bda80a93f2a.jpg" } ] } ], "index": 1, "angle": 0, "type": "image_body" } ], "index": 1 }, { "bbox": [ 86, 119, 498, 147 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 119, 499, 132 ], "spans": [ { "bbox": [ 110, 119, 499, 132 ], "type": "text", "content": "可见，sda1、sda2、sda5 是同一类块设备，它们的主设备号都是8，次设备号分别是1、", "score": 1.0 } ] }, { "bbox": [ 86, 135, 123, 150 ], "spans": [ { "bbox": [ 86, 135, 123, 150 ], "type": "text", "content": "2 和 5。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 150, 505, 179 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 151, 506, 163 ], "spans": [ { "bbox": [ 110, 151, 506, 163 ], "type": "text", "content": "由主设备号和次设备号组成了设备的唯一编号：设备号，其类型为 dev_t，是一个 32", "score": 1.0 } ] }, { "bbox": [ 89, 166, 426, 180 ], "spans": [ { "bbox": [ 89, 166, 426, 180 ], "type": "text", "content": "位的无符号整数，定义在/usr/src/linux-4.4.19/include/linux/types.h 文件中：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 182, 246, 195 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 108, 180, 246, 198 ], "spans": [ { "bbox": [ 108, 180, 246, 198 ], "type": "text", "content": "typedef __u32 __kernel_dev_t;", "score": 1.0 } ] } ] }, { "bbox": [ 108, 198, 264, 211 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 108, 195, 267, 214 ], "spans": [ { "bbox": [ 108, 195, 215, 214 ], "type": "text", "content": "typedef __kernel_dev_t", "score": 1.0 }, { "bbox": [ 233, 196, 267, 213 ], "type": "text", "content": "dev_t;", "score": 1.0 } ] } ] }, { "bbox": [ 107, 221, 241, 233 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 221, 241, 234 ], "spans": [ { "bbox": [ 109, 221, 241, 234 ], "type": "text", "content": "2. 与设备号相关的操作函数", "score": 1.0 } ] } ] }, { "bbox": [ 112, 244, 355, 257 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 113, 243, 356, 259 ], "spans": [ { "bbox": [ 113, 243, 356, 259 ], "type": "text", "content": "（1） 定义在/usr/include/linux/kdev_t.h 中的三个宏：", "score": 1.0 } ] } ] }, { "bbox": [ 129, 259, 504, 319 ], "type": "list", "angle": 0, "index": 11, "blocks": [ { "bbox": [ 129, 259, 504, 273 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 131, 258, 506, 276 ], "spans": [ { "bbox": [ 131, 259, 146, 273 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.69 }, { "bbox": [ 146, 258, 307, 276 ], "type": "text", "content": "#define MAJOR(dev) ((dev)>>8)", "score": 1.0 }, { "bbox": [ 324, 259, 506, 275 ], "type": "text", "content": "//从 dev（dev_t 类型）中获得主设备号", "score": 1.0 } ] } ] }, { "bbox": [ 130, 275, 504, 289 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 131, 275, 506, 290 ], "spans": [ { "bbox": [ 131, 275, 146, 289 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.73 }, { "bbox": [ 146, 275, 506, 290 ], "type": "text", "content": "#define MINOR(dev) ((dev) & 0xff) //从 dev（dev_t 类型）中获得次设备号", "score": 1.0 } ] } ] }, { "bbox": [ 130, 290, 504, 319 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 131, 290, 506, 305 ], "spans": [ { "bbox": [ 131, 290, 146, 305 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.74 }, { "bbox": [ 146, 290, 506, 305 ], "type": "text", "content": "#define MKDEV(ma,mi) ((ma)<<8 | (mi)) //将主、次设备号组合成 dev_t 类型", "score": 1.0 } ] }, { "bbox": [ 352, 306, 398, 321 ], "spans": [ { "bbox": [ 352, 306, 398, 321 ], "type": "text", "content": "的设备号", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 111, 322, 277, 334 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 113, 322, 277, 337 ], "spans": [ { "bbox": [ 113, 322, 277, 337 ], "type": "text", "content": "（2） 为字符设备静态分配设备号：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 337, 503, 382 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 110, 338, 497, 349 ], "spans": [ { "bbox": [ 110, 338, 497, 349 ], "type": "text", "content": "如果驱动程序开发者清楚了解系统中尚未被使用的设备号，则可直接指定主设备号，", "score": 1.0 } ] }, { "bbox": [ 88, 353, 504, 366 ], "spans": [ { "bbox": [ 88, 353, 504, 366 ], "type": "text", "content": "然后再申请若干个连续的次设备号。这种方法可能会造成系统中设备号冲突，而使驱动程", "score": 1.0 } ] }, { "bbox": [ 88, 370, 452, 382 ], "spans": [ { "bbox": [ 88, 370, 452, 382 ], "type": "text", "content": "序无法注册。函数原型定义在/usr/src/linux-4.4.19/include/linux/fs.h 文件中，为：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 386, 416, 397 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 108, 385, 417, 399 ], "spans": [ { "bbox": [ 108, 385, 417, 399 ], "type": "text", "content": "int register_chrdev_region(dev_t first, unsigned int count, char *name);", "score": 1.0 } ] } ] }, { "bbox": [ 107, 400, 483, 412 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 401, 483, 413 ], "spans": [ { "bbox": [ 110, 401, 483, 413 ], "type": "text", "content": "函数功能：为一个指定主设备号的字符驱动程序申请一个或一组连续的次设备号。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 416, 157, 428 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 108, 414, 159, 430 ], "spans": [ { "bbox": [ 108, 414, 159, 430 ], "type": "text", "content": "输入参数：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 431, 399, 444 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 108, 430, 401, 446 ], "spans": [ { "bbox": [ 108, 430, 401, 446 ], "type": "text", "content": "first ：dev_t 类型的起始设备号（可通过 MKDEV(major,0)获得）；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 447, 265, 460 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 448, 265, 459 ], "spans": [ { "bbox": [ 109, 448, 265, 459 ], "type": "text", "content": "count：需要申请的次设备号数量；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 463, 354, 476 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 461, 355, 477 ], "spans": [ { "bbox": [ 109, 461, 355, 477 ], "type": "text", "content": "name：设备名，会出现在 /proc/devices 和 sysfs 中；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 478, 351, 490 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 110, 478, 350, 491 ], "spans": [ { "bbox": [ 110, 478, 350, 491 ], "type": "text", "content": "返回值：分配成功返回0，失败返回一个负的错误码", "score": 1.0 } ] } ] }, { "bbox": [ 111, 493, 277, 506 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 493, 277, 507 ], "spans": [ { "bbox": [ 114, 493, 138, 507 ], "type": "text", "content": "（3）", "score": 1.0 }, { "bbox": [ 140, 494, 277, 506 ], "type": "text", "content": "为字符设备动态分配设备号：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 509, 496, 537 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 110, 509, 498, 522 ], "spans": [ { "bbox": [ 110, 509, 498, 522 ], "type": "text", "content": "如果没有提前指定主设备号，则采用动态申请方式，它不会出现设备号冲突的问题，", "score": 1.0 } ] }, { "bbox": [ 89, 526, 436, 537 ], "spans": [ { "bbox": [ 89, 526, 436, 537 ], "type": "text", "content": "但是无法在安装驱动前创建设备文件（因为安装前还没有分配到主设备号）。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 540, 389, 553 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 109, 539, 390, 555 ], "spans": [ { "bbox": [ 109, 539, 390, 555 ], "type": "text", "content": "函数原型定义在/usr/src/linux-4.4.19/include/linux/fs.h 文件中：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 556, 473, 569 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 107, 555, 475, 571 ], "spans": [ { "bbox": [ 107, 555, 475, 571 ], "type": "text", "content": "int alloc_chrdev_region(dev_t *dev,unsigned firstminor,unsigned count,char *name)；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 571, 399, 584 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 110, 571, 399, 584 ], "spans": [ { "bbox": [ 110, 571, 399, 584 ], "type": "text", "content": "函数功能：动态分配一个主设备号及一个或一组连续次设备号。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 587, 157, 599 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 108, 586, 159, 602 ], "spans": [ { "bbox": [ 108, 586, 159, 602 ], "type": "text", "content": "输入参数：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 602, 304, 615 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 108, 602, 305, 617 ], "spans": [ { "bbox": [ 108, 602, 305, 617 ], "type": "text", "content": "firstminor：起始次设备号，一般从 0 开始；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 618, 265, 630 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 109, 619, 265, 631 ], "spans": [ { "bbox": [ 109, 619, 265, 631 ], "type": "text", "content": "count：需要分配的次设备号数量；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 634, 354, 646 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 109, 634, 355, 649 ], "spans": [ { "bbox": [ 109, 634, 355, 649 ], "type": "text", "content": "name：设备名，会出现在 /proc/devices 和 sysfs 中；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 650, 333, 661 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 109, 650, 334, 662 ], "spans": [ { "bbox": [ 109, 650, 334, 662 ], "type": "text", "content": "输出参数：系统自动分配的 dev_t类型的设备号；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 665, 354, 677 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 110, 666, 355, 678 ], "spans": [ { "bbox": [ 110, 666, 355, 678 ], "type": "text", "content": "返回值：分配成功返回0，失败返回一个负的错误码。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 681, 202, 693 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 113, 680, 204, 694 ], "spans": [ { "bbox": [ 113, 680, 204, 694 ], "type": "text", "content": "（4） 释放设备号：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 696, 503, 740 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 110, 698, 503, 708 ], "spans": [ { "bbox": [ 110, 698, 503, 708 ], "type": "text", "content": "采用上面两种方式申请到的设备号，在设备不使用时，比如在调用cdev_del()函数从系", "score": 1.0 } ] }, { "bbox": [ 89, 713, 503, 725 ], "spans": [ { "bbox": [ 89, 713, 503, 725 ], "type": "text", "content": "统中注销字符设备之后，应该及时释放掉。释放设备号使用的函数原型定义在", "score": 1.0 } ] }, { "bbox": [ 88, 728, 295, 740 ], "spans": [ { "bbox": [ 88, 728, 295, 740 ], "type": "text", "content": "/usr/src/linux-4.4.19/include/linux/fs.h 文件中：", "score": 1.0 } ] } ] }, { "bbox": [ 127, 743, 389, 756 ], "type": "text", "angle": 0, "index": 34, "lines": [ { "bbox": [ 130, 743, 390, 759 ], "spans": [ { "bbox": [ 130, 743, 390, 759 ], "type": "text", "content": "void unregister_chrdev_region(dev_t from, unsigned count);", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 37 }, { "para_blocks": [ { "bbox": [ 107, 72, 277, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 72, 279, 86 ], "spans": [ { "bbox": [ 109, 72, 279, 86 ], "type": "text", "content": "其中参数含义跟上面（2）中的一样。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 89, 244, 100 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 113, 88, 245, 102 ], "spans": [ { "bbox": [ 113, 88, 245, 102 ], "type": "text", "content": "（5） 查看设备号使用情况：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 103, 505, 132 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 111, 105, 503, 116 ], "spans": [ { "bbox": [ 111, 105, 503, 116 ], "type": "text", "content": "当静态分配设备号时，需要查看系统中已经使用掉的设备号，从而决定使用哪个新设", "score": 1.0 } ] }, { "bbox": [ 88, 119, 494, 133 ], "spans": [ { "bbox": [ 88, 119, 494, 133 ], "type": "text", "content": "备号。可使用命令“cat /proc/devices”查看，显示的字符设备的最后一行信息如下所示：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 136, 198, 147 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 134, 199, 149 ], "spans": [ { "bbox": [ 109, 134, 199, 149 ], "type": "text", "content": "Character devices:", "score": 1.0 } ] } ] }, { "bbox": [ 119, 152, 184, 163 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 119, 148, 186, 168 ], "spans": [ { "bbox": [ 119, 150, 140, 165 ], "type": "text", "content": "254", "score": 1.0 }, { "bbox": [ 159, 148, 186, 168 ], "type": "text", "content": "mdp", "score": 1.0 } ] } ] }, { "bbox": [ 108, 166, 312, 179 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 166, 313, 179 ], "spans": [ { "bbox": [ 110, 166, 313, 179 ], "type": "text", "content": "则新添加设备驱动时可以选择主设备号255。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 189, 298, 203 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 115, 189, 298, 204 ], "spans": [ { "bbox": [ 115, 189, 298, 204 ], "type": "text", "content": "3.2.3 字符设备管理相关数据结构", "score": 1.0 } ] } ] }, { "bbox": [ 108, 221, 210, 232 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 108, 221, 211, 235 ], "spans": [ { "bbox": [ 108, 221, 211, 235 ], "type": "text", "content": "1. struct cdev 结构", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 96, 243, 496, 396 ], "blocks": [ { "bbox": [ 96, 243, 496, 396 ], "lines": [ { "bbox": [ 96, 243, 496, 396 ], "spans": [ { "bbox": [ 96, 243, 496, 396 ], "type": "text", "content": "Linux内核中使用structcdev来描述一个字符设备，定义在/usr/src/linux-4.4.19/ \ninclude/linux/cdev.h文件中：struct cdev{struct kobject kobj; /*内嵌的内核对象，包括引用计数、名称、父指针等*/struct module \\*owner; /*所属内核模块，一般设置为THISMODULE*/const struct file_operations \\*ops; /*设备操作集合\\*/struct list_head list; /*设备的inode链表头\\*/dev_t dev; /*设备号\\*/unsigned int count; /*分配的设备号数目\\*/}；" } ] } ], "index": 9, "angle": 0, "type": "code_body" } ], "index": 9, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 86, 400, 505, 444 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 119, 401, 505, 412 ], "spans": [ { "bbox": [ 119, 401, 505, 412 ], "type": "text", "content": "cdev 结构是内核对字符设备的标准描述，在实际的设备驱动开发中，通常使用自定", "score": 1.0 } ] }, { "bbox": [ 89, 416, 506, 428 ], "spans": [ { "bbox": [ 89, 416, 506, 428 ], "type": "text", "content": "义的结构体来描述一个特定的字符设备：内嵌 cdev 结构，同时包含其他描述该具体设备特", "score": 1.0 } ] }, { "bbox": [ 88, 431, 346, 444 ], "spans": [ { "bbox": [ 88, 431, 346, 444 ], "type": "text", "content": "性的字段。比如本实验中，用一段内存来模拟字符设备：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 117, 448, 243, 522 ], "blocks": [ { "bbox": [ 117, 448, 243, 522 ], "lines": [ { "bbox": [ 117, 448, 243, 522 ], "spans": [ { "bbox": [ 117, 448, 243, 522 ], "type": "text", "content": "struct mymem_dev\n{\n Struct cdev cdev;\n Unsigned char mem[512];\n};" } ] } ], "index": 11, "angle": 0, "type": "code_body" } ], "index": 11, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 108, 533, 282, 545 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 533, 283, 547 ], "spans": [ { "bbox": [ 109, 533, 283, 547 ], "type": "text", "content": "2. struct char_device_struct 结构", "score": 1.0 } ] } ] }, { "bbox": [ 86, 555, 505, 584 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 555, 506, 570 ], "spans": [ { "bbox": [ 109, 555, 506, 570 ], "type": "text", "content": "内核为主设备号相同的一组设备设置一个 char_device_struct 结构，描述这个主设备号", "score": 1.0 } ] }, { "bbox": [ 90, 572, 232, 583 ], "spans": [ { "bbox": [ 90, 572, 232, 583 ], "type": "text", "content": "下已经被分配的次设备号区间：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 119, 587, 489, 725 ], "blocks": [ { "bbox": [ 119, 587, 489, 725 ], "lines": [ { "bbox": [ 119, 587, 489, 725 ], "spans": [ { "bbox": [ 119, 587, 489, 725 ], "type": "text", "content": "static struct char_device_struct{ struct char_device_struct \\*next; /*指向散列链表中的下一个元素的指针*/ unsigned int major; /\\*主设备号\\*/ unsigned int baseminor; /\\*起始次设备号\\*/ int minorct; /\\*次设备号区间大小\\*/ char name[64]; /\\*设备名\\*/ struct file_operations \\*fops; /\\*未使用\\*/ struct cdev \\*cdev; /\\*指向字符设备描述符的指针\\*/ \n\\*chrdevs[CHRDEV Major HASH SIZE];" } ] } ], "index": 14, "angle": 0, "type": "code_body" } ], "index": 14, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 107, 735, 227, 748 ], "type": "title", "angle": 0, "index": 15, "lines": [ { "bbox": [ 107, 735, 227, 750 ], "spans": [ { "bbox": [ 107, 735, 227, 750 ], "type": "text", "content": "3. file_operations 结构", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 38 }, { "para_blocks": [ { "bbox": [ 86, 72, 505, 116 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 108, 73, 505, 85 ], "spans": [ { "bbox": [ 108, 73, 505, 85 ], "type": "text", "content": "file_operations 结构体是字符设备中最重要的数据结构之一。其中的成员是一组函数指", "score": 1.0 } ] }, { "bbox": [ 88, 88, 505, 103 ], "spans": [ { "bbox": [ 88, 88, 505, 103 ], "type": "text", "content": "针，用于实现相应的系统调用，如 open()、read()、write()、close()、seek()、ioctl()等系统调", "score": 1.0 } ] }, { "bbox": [ 89, 104, 400, 116 ], "spans": [ { "bbox": [ 89, 104, 400, 116 ], "type": "text", "content": "用最终就是这组函数实现的，是字符设备驱动程序设计的主体内容。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 119, 381, 132 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 119, 382, 133 ], "spans": [ { "bbox": [ 108, 119, 382, 133 ], "type": "text", "content": "file_operations 结构体中对字符设备比较重要的成员主要有：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 136, 506, 288 ], "blocks": [ { "bbox": [ 108, 136, 506, 288 ], "lines": [ { "bbox": [ 108, 136, 506, 288 ], "spans": [ { "bbox": [ 108, 136, 506, 288 ], "type": "text", "content": "struct file_operations{ struct module \\*owner; /*拥有该结构的模块，一般为THIS_MODULE*/ ssize_t (*read) (struct file \\*, char __user \\*, size_t, loff_t \\*); /*从设备中读取数据*/ ssize_t (\\*write) (struct file \\*, const char __user \\*, size_t, loff_t \\*);/*向设备中写数据*/ int (\\*ioctl) (struct inode \\*, struct file \\*, unsigned int, unsigned long); /*执行设备的I/O 控制命令\\*/ int (\\*open) (struct inode \\*, struct file \\*); /*打开设备文件\\*/ int (\\*release) (struct inode \\*, struct file \\*); /*关闭设备文件\\*/" } ] } ], "index": 3, "angle": 0, "type": "code_body" } ], "index": 3, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 107, 314, 167, 326 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 108, 314, 168, 327 ], "spans": [ { "bbox": [ 108, 314, 168, 327 ], "type": "text", "content": "4. file 结构", "score": 1.0 } ] } ] }, { "bbox": [ 86, 337, 505, 365 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 108, 338, 506, 350 ], "spans": [ { "bbox": [ 108, 338, 506, 350 ], "type": "text", "content": "file 结构代表一个打开的文件，内核每执行一次 open操作就会建立一个file 结构，因此", "score": 1.0 } ] }, { "bbox": [ 89, 352, 356, 367 ], "spans": [ { "bbox": [ 89, 352, 356, 367 ], "type": "text", "content": "一个文件可以对应多个 file 结构。其中几个重要的成员有：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 107, 370, 445, 476 ], "blocks": [ { "bbox": [ 107, 370, 445, 476 ], "lines": [ { "bbox": [ 107, 370, 445, 476 ], "spans": [ { "bbox": [ 107, 370, 445, 476 ], "type": "text", "content": "struct file{\nmode_t fmode; /*文件模式，如FMODE_READ，FMODE_WRITE*/\nloff_t f_pos; /*当前读写指针*/\nstruct file_operations *f_op; /*文件操作函数表指针*/\nvoid *private_data; /*非常重要，用于存放转换后的设备描述结构指针*/\n};" } ] } ], "index": 6, "angle": 0, "type": "code_body" } ], "index": 6, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 107, 486, 182, 497 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 107, 485, 184, 499 ], "spans": [ { "bbox": [ 107, 485, 184, 499 ], "type": "text", "content": "5. inode 结构", "score": 1.0 } ] } ] }, { "bbox": [ 107, 508, 456, 523 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 509, 457, 523 ], "spans": [ { "bbox": [ 109, 509, 457, 523 ], "type": "text", "content": "磁盘上每个文件都有一个 inode，对于设备文件来说，有两个很重要的成员：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 526, 342, 599 ], "blocks": [ { "bbox": [ 108, 526, 342, 599 ], "lines": [ { "bbox": [ 108, 526, 342, 599 ], "spans": [ { "bbox": [ 108, 526, 342, 599 ], "type": "text", "content": "struct inode {\n dev_t i_rdev; /*设备号*/\n struct cdev *i_cdev; /*该设备的 cdev 结构*/\n ......\n};" } ] } ], "index": 9, "angle": 0, "type": "code_body" } ], "index": 9, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 107, 602, 324, 614 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 602, 326, 616 ], "spans": [ { "bbox": [ 109, 602, 326, 616 ], "type": "text", "content": "根据其设备号可以得到其主设备号和次设备号。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 654, 348, 670 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 653, 349, 671 ], "spans": [ { "bbox": [ 114, 653, 349, 671 ], "type": "text", "content": "3.3 linux 字符设备驱动程序的设计", "score": 1.0 } ] } ] }, { "bbox": [ 113, 700, 307, 714 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 700, 307, 714 ], "spans": [ { "bbox": [ 114, 700, 307, 714 ], "type": "text", "content": "3.3.1 linux 字符设备驱动程序框架", "score": 1.0 } ] } ] }, { "bbox": [ 107, 724, 311, 737 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 108, 724, 312, 737 ], "spans": [ { "bbox": [ 108, 724, 312, 737 ], "type": "text", "content": "Linux字符设备驱动程序框架如图 3-1所示：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 39 }, { "para_blocks": [ { "type": "image", "bbox": [ 109, 71, 469, 304 ], "blocks": [ { "bbox": [ 109, 71, 469, 304 ], "lines": [ { "bbox": [ 109, 71, 469, 304 ], "spans": [ { "bbox": [ 109, 71, 469, 304 ], "type": "image", "image_path": "094cf3a8258652b6f4357299f1d4d3141e1b739b8b0535754fb786d20832020a.jpg" } ] } ], "index": 1, "angle": 0, "type": "image_body" }, { "bbox": [ 207, 306, 359, 319 ], "lines": [ { "bbox": [ 209, 307, 358, 319 ], "spans": [ { "bbox": [ 209, 307, 358, 319 ], "type": "text", "content": "图3-1 字符设备驱动程序框架图", "score": 1.0 } ] } ], "index": 2, "angle": 0, "type": "image_caption" } ], "index": 1 }, { "bbox": [ 113, 329, 392, 343 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 114, 328, 392, 344 ], "spans": [ { "bbox": [ 114, 328, 392, 344 ], "type": "text", "content": "3.3.2 linux 字符设备驱动程序中需要的一组头文件", "score": 1.0 } ] } ] }, { "bbox": [ 107, 353, 398, 366 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 354, 398, 367 ], "spans": [ { "bbox": [ 109, 354, 398, 367 ], "type": "text", "content": "在编写 linux 字符设备驱动程序时，可能要用到的头文件包括：", "score": 1.0 } ] } ] }, { "bbox": [ 121, 369, 476, 382 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 123, 368, 475, 384 ], "spans": [ { "bbox": [ 123, 368, 475, 384 ], "type": "text", "content": "#include //定义文件表结构（file 结构,buffer_head,m_inode 等）", "score": 1.0 } ] } ] }, { "bbox": [ 121, 384, 505, 428 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 123, 382, 506, 399 ], "spans": [ { "bbox": [ 123, 382, 506, 399 ], "type": "text", "content": "#include //对一些特殊的系统数据类型的定义，例如 dev_t, off_t,", "score": 1.0 } ] }, { "bbox": [ 124, 400, 506, 413 ], "spans": [ { "bbox": [ 124, 400, 506, 413 ], "type": "text", "content": "pid_t.其实这些类型大部分都是 unsigned int 型通过一连串的 typedef 变过来的，只是", "score": 1.0 } ] }, { "bbox": [ 124, 415, 196, 428 ], "spans": [ { "bbox": [ 124, 415, 196, 428 ], "type": "text", "content": "为了方便阅读。", "score": 1.0 } ] } ] }, { "bbox": [ 121, 431, 420, 444 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 123, 431, 420, 445 ], "spans": [ { "bbox": [ 123, 431, 420, 445 ], "type": "text", "content": "#include //包含了 cdev 结构及相关函数的定义。", "score": 1.0 } ] } ] }, { "bbox": [ 121, 447, 455, 460 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 123, 446, 455, 462 ], "spans": [ { "bbox": [ 123, 446, 455, 462 ], "type": "text", "content": "#include //包含 copy_to_user(),copy_from_user()的定义", "score": 1.0 } ] } ] }, { "bbox": [ 121, 462, 335, 475 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 123, 463, 336, 476 ], "spans": [ { "bbox": [ 123, 463, 336, 476 ], "type": "text", "content": "#include //模块编程相关函数", "score": 1.0 } ] } ] }, { "bbox": [ 121, 478, 330, 491 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 123, 478, 330, 491 ], "spans": [ { "bbox": [ 123, 478, 330, 491 ], "type": "text", "content": "#Include //模块编程相关函数", "score": 1.0 } ] } ] }, { "bbox": [ 122, 494, 226, 506 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 124, 493, 227, 507 ], "spans": [ { "bbox": [ 124, 493, 227, 507 ], "type": "text", "content": "#include ", "score": 1.0 } ] } ] }, { "bbox": [ 121, 509, 483, 523 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 123, 508, 484, 524 ], "spans": [ { "bbox": [ 123, 508, 484, 524 ], "type": "text", "content": "#include //包含内核的内存分配相关函数，如 kmalloc()/kfree()等", "score": 1.0 } ] } ] }, { "bbox": [ 113, 532, 295, 544 ], "type": "title", "angle": 0, "index": 13, "lines": [ { "bbox": [ 115, 532, 295, 546 ], "spans": [ { "bbox": [ 115, 532, 295, 546 ], "type": "text", "content": "3.3.3 字符设备驱动程序的初始化", "score": 1.0 } ] } ] }, { "bbox": [ 108, 564, 183, 576 ], "type": "title", "angle": 0, "index": 14, "lines": [ { "bbox": [ 108, 563, 184, 577 ], "spans": [ { "bbox": [ 108, 563, 184, 577 ], "type": "text", "content": "1. 分配设备号", "score": 1.0 } ] } ] }, { "bbox": [ 86, 587, 503, 615 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 588, 503, 599 ], "spans": [ { "bbox": [ 110, 588, 503, 599 ], "type": "text", "content": "如3.2.2 节所述，为一个新字符设备分配设备号可以有静态和动态两种方式，如果提前", "score": 1.0 } ] }, { "bbox": [ 88, 602, 241, 615 ], "spans": [ { "bbox": [ 88, 602, 241, 615 ], "type": "text", "content": "指定主设备号，则使用静态方式：", "score": 1.0 } ] } ] }, { "bbox": [ 88, 618, 416, 632 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 108, 618, 417, 634 ], "spans": [ { "bbox": [ 108, 618, 417, 634 ], "type": "text", "content": "int register_chrdev_region(dev_t first, unsigned int count, char *name);", "score": 1.0 } ] } ] }, { "bbox": [ 88, 634, 199, 646 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 89, 634, 199, 646 ], "spans": [ { "bbox": [ 89, 634, 199, 646 ], "type": "text", "content": "否则使用动态分配方式：", "score": 1.0 } ] } ] }, { "bbox": [ 106, 650, 473, 663 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 108, 650, 474, 665 ], "spans": [ { "bbox": [ 108, 650, 474, 665 ], "type": "text", "content": "int alloc_chrdev_region(dev_t *dev,unsigned firstminor,unsigned count,char *name)；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 673, 244, 685 ], "type": "title", "angle": 0, "index": 19, "lines": [ { "bbox": [ 108, 672, 244, 687 ], "spans": [ { "bbox": [ 108, 672, 244, 687 ], "type": "text", "content": "2. 定义 cdev 结构并初始化", "score": 1.0 } ] } ] }, { "bbox": [ 86, 696, 505, 724 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 109, 697, 505, 709 ], "spans": [ { "bbox": [ 109, 697, 505, 709 ], "type": "text", "content": "linux内核必须为每个字符设备都建立一个 cdev结构，定义时采用cdev 结构体指针或变", "score": 1.0 } ] }, { "bbox": [ 89, 712, 346, 724 ], "spans": [ { "bbox": [ 89, 712, 346, 724 ], "type": "text", "content": "量均可，只不过两种定义方式的初始化操作会有所不同：", "score": 1.0 } ] } ] }, { "bbox": [ 112, 728, 270, 740 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 113, 726, 270, 741 ], "spans": [ { "bbox": [ 113, 726, 270, 741 ], "type": "text", "content": "（1） 定义 cdev 结构体及初始化：", "score": 1.0 } ] } ] }, { "bbox": [ 143, 744, 236, 756 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 143, 742, 238, 758 ], "spans": [ { "bbox": [ 143, 742, 238, 758 ], "type": "text", "content": "struct cdev my_cdev;", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 40 }, { "para_blocks": [ { "type": "code", "bbox": [ 143, 73, 291, 101 ], "blocks": [ { "bbox": [ 143, 73, 291, 101 ], "lines": [ { "bbox": [ 143, 73, 291, 101 ], "spans": [ { "bbox": [ 143, 73, 291, 101 ], "type": "text", "content": "cdev_init(&my_cdev, &fops); \nmy_cdev owner = THISMODULE;" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 113, 104, 281, 116 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 113, 103, 282, 119 ], "spans": [ { "bbox": [ 113, 103, 282, 119 ], "type": "text", "content": "（2） 定义 cdev 结构指针及初始化：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 143, 120, 303, 163 ], "blocks": [ { "bbox": [ 143, 120, 303, 163 ], "lines": [ { "bbox": [ 143, 120, 303, 163 ], "spans": [ { "bbox": [ 143, 120, 303, 163 ], "type": "text", "content": "struct cdev *my_cdev = cdev_alloc();\nmy_cdev->ops = &fops;\nmy_cdev->owner = THISMODULE;" } ] } ], "index": 3, "angle": 0, "type": "code_body" } ], "index": 3, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 86, 166, 498, 194 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 114, 166, 500, 179 ], "spans": [ { "bbox": [ 114, 166, 500, 179 ], "type": "text", "content": "其实，cdev_init()和cdev_alloc()的功能是差不多的，只是前者多了一个ops的赋值操作，", "score": 1.0 } ] }, { "bbox": [ 89, 182, 273, 195 ], "spans": [ { "bbox": [ 89, 182, 273, 195 ], "type": "text", "content": "具体区别参看下面两个函数的实现代码：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 122, 196, 414, 459 ], "blocks": [ { "bbox": [ 122, 196, 414, 459 ], "lines": [ { "bbox": [ 122, 196, 414, 459 ], "spans": [ { "bbox": [ 122, 196, 414, 459 ], "type": "text", "content": "struct cdev *cdev_alloc(void) \n{ \n struct cdev *p = kzalloc(sizeof(struct cdev), GFP_KERNEL); \n if (p) { \n INIT_LIST_HEAD(&p->list); \n kobject_init(&p->kobj, &ktype_cdev_dynamic); \n } \n return p; \n} \nvoid cdev_init(struct cdev *cdev, const struct file_operations *fops) \n{ \n memset(cdev, 0, sizeof *cdev); \n INIT_LIST_HEAD(&cdev->list); \n kobject_init(&cdev->kobj, &ktype_cdev_default); \n cdev->ops = fops;" } ] } ], "index": 5, "angle": 0, "type": "code_body" } ], "index": 5, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 123, 462, 447, 475 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 124, 462, 449, 476 ], "spans": [ { "bbox": [ 124, 462, 449, 476 ], "type": "text", "content": "两个函数的原型定义在/usr/src/linux-4.4.19/include/linux/cdev.h 文件中。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 486, 202, 498 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 108, 486, 203, 500 ], "spans": [ { "bbox": [ 108, 486, 203, 500 ], "type": "text", "content": "3. 注册 cdev 结构", "score": 1.0 } ] } ] }, { "bbox": [ 86, 509, 504, 538 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 110, 510, 503, 521 ], "spans": [ { "bbox": [ 110, 510, 503, 521 ], "type": "text", "content": "cdev 初始化完成后，应将其注册到系统中，一般在模块加载时完成该操作。设备注册", "score": 1.0 } ] }, { "bbox": [ 89, 525, 467, 538 ], "spans": [ { "bbox": [ 89, 525, 467, 538 ], "type": "text", "content": "函数是 cdev_add()，其原型定义在/usr/src/linux-4.4.19/include/linux/cdev.h 文件中：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 107, 540, 487, 631 ], "blocks": [ { "bbox": [ 107, 540, 487, 631 ], "lines": [ { "bbox": [ 107, 540, 487, 631 ], "spans": [ { "bbox": [ 107, 540, 487, 631 ], "type": "text", "content": "int cdev_add(struct cdev *p, dev_t dev, unsigned count) \n{ \n p->dev = dev; \n p->count = count; \n return kobj_map(cdev_map, dev, count, NULL, exact_MATCH, exact_lock, p); \n}" } ] } ], "index": 9, "angle": 0, "type": "code_body" } ], "index": 9, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 108, 634, 420, 646 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 634, 420, 647 ], "spans": [ { "bbox": [ 110, 634, 420, 647 ], "type": "text", "content": "其中的输入参数分别是 cdev 结构指针、起始设备号、次设备号数量", "score": 1.0 } ] } ] }, { "bbox": [ 86, 649, 503, 709 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 108, 649, 500, 662 ], "spans": [ { "bbox": [ 108, 649, 500, 662 ], "type": "text", "content": "linux 内核中所有字符设备都记录在一个 kobj_map 结构的 cdev_map 散列表里。", "score": 1.0 } ] }, { "bbox": [ 88, 666, 503, 678 ], "spans": [ { "bbox": [ 88, 666, 503, 678 ], "type": "text", "content": "cdev_add() 函 数 中 的 kobj_map() 函 数 就 是 用 来 把 设 备 号 及 cdev 结 构 一 起 保 存 到", "score": 1.0 } ] }, { "bbox": [ 88, 681, 499, 694 ], "spans": [ { "bbox": [ 88, 681, 499, 694 ], "type": "text", "content": "cdev_map 散列表里。当以后要打开这个字符设备文件时，通过调用 kobj_lookup() 函数，", "score": 1.0 } ] }, { "bbox": [ 89, 697, 403, 709 ], "spans": [ { "bbox": [ 89, 697, 403, 709 ], "type": "text", "content": "根据设备号就可以找到 cdev 结构变量，从而取出其中的 ops 字段。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 712, 503, 740 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 110, 712, 503, 724 ], "spans": [ { "bbox": [ 110, 712, 503, 724 ], "type": "text", "content": "执行 cdev_add()操作后，意味着一个字符设备对象已经加入了系统，以后用户程序可", "score": 1.0 } ] }, { "bbox": [ 90, 728, 284, 739 ], "spans": [ { "bbox": [ 90, 728, 284, 739 ], "type": "text", "content": "以通过文件系统接口找到对应的驱动程序。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 750, 331, 764 ], "type": "title", "angle": 0, "index": 13, "lines": [ { "bbox": [ 115, 751, 331, 764 ], "spans": [ { "bbox": [ 115, 751, 331, 764 ], "type": "text", "content": "3.3.4 实现字符设备驱动程序的操作函数", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 41 }, { "para_blocks": [ { "bbox": [ 108, 80, 327, 94 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 108, 79, 327, 95 ], "spans": [ { "bbox": [ 108, 79, 327, 95 ], "type": "text", "content": "1. 实现 file_operations 结构中要用到的函数", "score": 1.0 } ] } ] }, { "bbox": [ 86, 104, 503, 132 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 104, 503, 116 ], "spans": [ { "bbox": [ 110, 104, 503, 116 ], "type": "text", "content": "这些函数具体实现设备的相关操作，如打开设备、读设备等，部分函数的大致结构可", "score": 1.0 } ] }, { "bbox": [ 88, 120, 168, 132 ], "spans": [ { "bbox": [ 88, 120, 168, 132 ], "type": "text", "content": "参看下面的描述：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 135, 238, 148 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 114, 134, 239, 150 ], "spans": [ { "bbox": [ 114, 134, 239, 150 ], "type": "text", "content": "（1） 打开设备函数 open：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 143, 151, 405, 242 ], "blocks": [ { "bbox": [ 143, 151, 405, 242 ], "lines": [ { "bbox": [ 143, 151, 405, 242 ], "spans": [ { "bbox": [ 143, 151, 405, 242 ], "type": "text", "content": "static int char_dev_open(struct inode *inode, struct file *filp) \n{ // 这里可以进行一些初始化 \n printf(\"char_dev_device_open.\\n\"); \n return 0; \n}" } ] } ], "index": 4, "angle": 0, "type": "code_body" } ], "index": 4, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 113, 244, 201, 257 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 243, 201, 259 ], "spans": [ { "bbox": [ 114, 243, 201, 259 ], "type": "text", "content": "（2） 读设备函数", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 143, 260, 490, 351 ], "blocks": [ { "bbox": [ 143, 260, 490, 351 ], "lines": [ { "bbox": [ 143, 260, 490, 351 ], "spans": [ { "bbox": [ 143, 260, 490, 351 ], "type": "text", "content": "ssize_t char_dev_read(struct file *file, char __user *buff, size_t count,loff_t *offp) {\n ...\n copy_to_user();\n ...\n}" } ] } ], "index": 6, "angle": 0, "type": "code_body" } ], "index": 6, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 113, 354, 201, 366 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 352, 200, 368 ], "spans": [ { "bbox": [ 114, 352, 138, 368 ], "type": "text", "content": "（3）", "score": 1.0 }, { "bbox": [ 142, 354, 200, 367 ], "type": "text", "content": "写设备函数", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 143, 370, 503, 476 ], "blocks": [ { "bbox": [ 143, 370, 503, 476 ], "lines": [ { "bbox": [ 143, 370, 503, 476 ], "spans": [ { "bbox": [ 143, 370, 503, 476 ], "type": "text", "content": "ssize_t char_dev_write(struct file *file, const char __user *buff, size_t count,loff_t *offp) \n{ \n ... \n copy_from_user(); \n ... \n}" } ] } ], "index": 8, "angle": 0, "type": "code_body" } ], "index": 8, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 113, 477, 208, 491 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 477, 208, 491 ], "spans": [ { "bbox": [ 114, 477, 208, 491 ], "type": "text", "content": "（4） I/O控制函数", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 143, 494, 474, 709 ], "blocks": [ { "bbox": [ 143, 494, 474, 709 ], "lines": [ { "bbox": [ 143, 494, 474, 709 ], "spans": [ { "bbox": [ 143, 494, 474, 709 ], "type": "text", "content": "static int char_dev_ioctl(struct inode *inode,struct file *filp,unsigned int cmd, unsigned long arg) \n{ ... switch(cmd) { case xxx_cmd1: break; case xxx_cmd2: break; ... }" } ] } ], "index": 10, "angle": 0, "type": "code_body" } ], "index": 10, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 113, 712, 402, 724 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 712, 402, 726 ], "spans": [ { "bbox": [ 114, 712, 402, 726 ], "type": "text", "content": "（5） 关闭设备函数 release，对应用户空间的 close 系统调用", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 143, 728, 413, 756 ], "blocks": [ { "bbox": [ 143, 728, 413, 756 ], "lines": [ { "bbox": [ 143, 728, 413, 756 ], "spans": [ { "bbox": [ 143, 728, 413, 756 ], "type": "text", "content": "static int char_dev_release(struct inode *node, struct file *file) {" } ] } ], "index": 12, "angle": 0, "type": "code_body" } ], "index": 12, "sub_type": "code", "guess_lang": "c" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 42 }, { "para_blocks": [ { "type": "code", "bbox": [ 143, 72, 312, 132 ], "blocks": [ { "bbox": [ 143, 72, 312, 132 ], "lines": [ { "bbox": [ 143, 72, 312, 132 ], "spans": [ { "bbox": [ 143, 72, 312, 132 ], "type": "text", "content": "//这里可以进行一些资源的释放printk(\"char_devdevice release.\\n\");return0;" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "javascript" }, { "bbox": [ 110, 142, 251, 156 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 142, 253, 158 ], "spans": [ { "bbox": [ 108, 142, 253, 158 ], "type": "text", "content": "2. 添加 file_operations 成员", "score": 1.0 } ] } ] }, { "bbox": [ 88, 165, 503, 194 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 167, 503, 179 ], "spans": [ { "bbox": [ 110, 167, 503, 179 ], "type": "text", "content": "file_operations结构体中包含很多函数指针，是驱动程序与内核的接口，下面列出最常", "score": 1.0 } ] }, { "bbox": [ 88, 182, 158, 195 ], "spans": [ { "bbox": [ 88, 182, 158, 195 ], "type": "text", "content": "用的几种操作：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 198, 330, 335 ], "blocks": [ { "bbox": [ 108, 198, 330, 335 ], "lines": [ { "bbox": [ 108, 198, 330, 335 ], "spans": [ { "bbox": [ 108, 198, 330, 335 ], "type": "text", "content": "static struct file_operations char_dev_fops = \n{ \n .owner = THISMODULE, \n .open = char_dev_open, //打开设备 \n .release = char_dev_release, //关闭设备 \n .read = char_dev_read, //实现设备读功能 \n .write = char_dev_write, //实现设备写功能 \n .ioct1 = char_dev_ioct1, //实现设备控制功能 \n};" } ] } ], "index": 4, "angle": 0, "type": "code_body" } ], "index": 4, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 115, 345, 198, 358 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 345, 199, 359 ], "spans": [ { "bbox": [ 114, 345, 199, 359 ], "type": "text", "content": "3.3.5 注销设备", "score": 1.0 } ] } ] }, { "bbox": [ 88, 368, 505, 397 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 111, 370, 505, 381 ], "spans": [ { "bbox": [ 111, 370, 505, 381 ], "type": "text", "content": "当不使用某个设备时，应及时从系统注销，以节省系统资源。注销设备主要包括两个操", "score": 1.0 } ] }, { "bbox": [ 89, 385, 431, 397 ], "spans": [ { "bbox": [ 89, 385, 431, 397 ], "type": "text", "content": "作：撤销cdev结构和释放设备号，此项工作通常放在模块卸载过程中完成。", "score": 1.0 } ] } ] }, { "bbox": [ 110, 407, 201, 420 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 407, 203, 422 ], "spans": [ { "bbox": [ 109, 407, 203, 422 ], "type": "text", "content": "1. 撤销 cdev 结构", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 430, 500, 523 ], "blocks": [ { "bbox": [ 108, 430, 500, 523 ], "lines": [ { "bbox": [ 108, 430, 500, 523 ], "spans": [ { "bbox": [ 108, 430, 500, 523 ], "type": "text", "content": "Linux内核使用cdev_del()函数向系统删除一个cdev，完成字符设备的注销： \nvoid cdev_del(struct cdev *p) \n{ \n cdev_unmap(p->dev, p->count); //调用 kobj_unmap()释放 cdev_map散列表中的对象 \n kobj_put(&p->kobj); //释放 cdev结构本身 \n}" } ] } ], "index": 8, "angle": 0, "type": "code_body" } ], "index": 8, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 110, 548, 182, 560 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 108, 548, 183, 561 ], "spans": [ { "bbox": [ 108, 548, 183, 561 ], "type": "text", "content": "2. 释放设备号", "score": 1.0 } ] } ] }, { "bbox": [ 88, 571, 504, 599 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 571, 506, 585 ], "spans": [ { "bbox": [ 110, 571, 506, 585 ], "type": "text", "content": "调用cdev_del()函数从系统注销字符设备之后，应调用unregister_chrdev_region()释放原", "score": 1.0 } ] }, { "bbox": [ 89, 587, 241, 600 ], "spans": [ { "bbox": [ 89, 587, 241, 600 ], "type": "text", "content": "先申请的设备号，其函数原型为：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 109, 603, 380, 616 ], "blocks": [ { "bbox": [ 109, 603, 380, 616 ], "lines": [ { "bbox": [ 109, 603, 380, 616 ], "spans": [ { "bbox": [ 109, 603, 380, 616 ], "type": "text", "content": "void unregister_chrdev_region(dev_t first, unsigned int count);" } ] } ], "index": 11, "angle": 0, "type": "code_body" } ], "index": 11, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 116, 638, 390, 655 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 637, 391, 656 ], "spans": [ { "bbox": [ 114, 637, 391, 656 ], "type": "text", "content": "3.4 linux 字符设备驱动程序的编译及加载", "score": 1.0 } ] } ] }, { "bbox": [ 88, 677, 504, 705 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 111, 677, 506, 690 ], "spans": [ { "bbox": [ 111, 677, 506, 690 ], "type": "text", "content": "当以模块方式实现一个字符设备的驱动程序后，可从按以下步骤对驱动程序进行编译和", "score": 1.0 } ] }, { "bbox": [ 86, 691, 117, 707 ], "spans": [ { "bbox": [ 86, 691, 117, 707 ], "type": "text", "content": "加载：", "score": 1.0 } ] } ] }, { "bbox": [ 110, 716, 171, 729 ], "type": "title", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 717, 172, 729 ], "spans": [ { "bbox": [ 109, 717, 172, 729 ], "type": "text", "content": "1. 编译模块", "score": 1.0 } ] } ] }, { "bbox": [ 113, 740, 420, 752 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 115, 740, 421, 754 ], "spans": [ { "bbox": [ 115, 740, 421, 754 ], "type": "text", "content": "在驱动程序源码文件所在目录中建立Makefile文件，参考内容如下：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 109, 756, 189, 768 ], "blocks": [ { "bbox": [ 109, 756, 189, 768 ], "lines": [ { "bbox": [ 109, 756, 189, 768 ], "spans": [ { "bbox": [ 109, 756, 189, 768 ], "type": "text", "content": "obj-m :=c_driver.o" } ] } ], "index": 16, "angle": 0, "type": "code_body" } ], "index": 16, "sub_type": "code", "guess_lang": "txt" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 43 }, { "para_blocks": [ { "type": "code", "bbox": [ 108, 73, 332, 163 ], "blocks": [ { "bbox": [ 108, 73, 332, 163 ], "lines": [ { "bbox": [ 108, 73, 332, 163 ], "spans": [ { "bbox": [ 108, 73, 332, 163 ], "type": "text", "content": "KDIR :=/usr/src/linux-headers-4.4.0-36-generic \nPWD :=$(shell pwd) \ndefault: \n make -C $(KDIR) M=$(PWD) modules \nclean: \n make -C $(KDIR) M=$(PWD) clean" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "makefile" }, { "bbox": [ 108, 166, 312, 179 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 166, 312, 180 ], "spans": [ { "bbox": [ 110, 166, 312, 180 ], "type": "text", "content": "然后使用make命令编译模块，得到.ko文件。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 190, 340, 202 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 190, 340, 204 ], "spans": [ { "bbox": [ 108, 190, 340, 204 ], "type": "text", "content": "2. 使用 insmod 命令加载模块（需要 root 权限）", "score": 1.0 } ] } ] }, { "bbox": [ 107, 212, 352, 226 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 108, 212, 353, 227 ], "spans": [ { "bbox": [ 108, 212, 353, 227 ], "type": "text", "content": "加载后可使用“cat /proc/devices”查看所加载的设备", "score": 1.0 } ] } ] }, { "bbox": [ 108, 236, 262, 249 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 109, 236, 261, 250 ], "spans": [ { "bbox": [ 109, 236, 261, 250 ], "type": "text", "content": "3. 建立设备节点（即设备文件）", "score": 1.0 } ] } ] }, { "bbox": [ 119, 259, 499, 287 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 121, 259, 499, 274 ], "spans": [ { "bbox": [ 121, 259, 499, 274 ], "type": "text", "content": "根据设备号在文件系统中建立对应的设备节点（即设备文件），使用命令 mknod，如：", "score": 1.0 } ] }, { "bbox": [ 136, 276, 265, 287 ], "spans": [ { "bbox": [ 136, 276, 265, 287 ], "type": "text", "content": "#mknod /dev/mycdev c 145 0", "score": 1.0 } ] } ] }, { "bbox": [ 108, 290, 362, 304 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 290, 362, 305 ], "spans": [ { "bbox": [ 109, 290, 362, 305 ], "type": "text", "content": "从而建立了/dev/mycdev 文件与（145,0）号设备的连接", "score": 1.0 } ] } ] }, { "bbox": [ 107, 314, 277, 327 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 315, 277, 327 ], "spans": [ { "bbox": [ 109, 315, 277, 327 ], "type": "text", "content": "4. 可根据需要修改设备文件的权限", "score": 1.0 } ] } ] }, { "bbox": [ 120, 338, 272, 350 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 120, 336, 273, 353 ], "spans": [ { "bbox": [ 120, 336, 273, 353 ], "type": "text", "content": "如：#chmod 777 /dev/mycdev", "score": 1.0 } ] } ] }, { "bbox": [ 124, 353, 504, 382 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 126, 353, 506, 367 ], "spans": [ { "bbox": [ 126, 353, 506, 367 ], "type": "text", "content": "至此，一个新设备建立完毕，以后应用程序就可以使用文件操作函数如“open”等", "score": 1.0 } ] }, { "bbox": [ 137, 370, 254, 381 ], "spans": [ { "bbox": [ 137, 370, 254, 381 ], "type": "text", "content": "操作/dev/mycdev 设备了。", "score": 1.0 } ] } ] }, { "bbox": [ 178, 417, 376, 439 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 177, 415, 377, 442 ], "spans": [ { "bbox": [ 177, 415, 238, 442 ], "type": "text", "content": "实验四", "score": 1.0 }, { "bbox": [ 249, 417, 377, 440 ], "type": "text", "content": "linux 进程管理", "score": 1.0 } ] } ] }, { "bbox": [ 114, 465, 273, 481 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 465, 274, 483 ], "spans": [ { "bbox": [ 114, 465, 274, 483 ], "type": "text", "content": "4.1 设计目的和内容要求", "score": 1.0 } ] } ] }, { "bbox": [ 108, 512, 168, 524 ], "type": "title", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 512, 168, 525 ], "spans": [ { "bbox": [ 109, 512, 168, 525 ], "type": "text", "content": "1. 设计目的", "score": 1.0 } ] } ] }, { "bbox": [ 86, 535, 505, 641 ], "type": "list", "angle": 0, "index": 19, "blocks": [ { "bbox": [ 113, 535, 241, 548 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 114, 535, 241, 549 ], "spans": [ { "bbox": [ 114, 535, 241, 549 ], "type": "text", "content": "（1）熟悉linux的命令接口。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 551, 503, 578 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 116, 552, 503, 563 ], "spans": [ { "bbox": [ 116, 552, 503, 563 ], "type": "text", "content": "（2）通过对linux 进程控制的相关系统调用的编程应用，进一步加深对进程概念的理解，", "score": 1.0 } ] }, { "bbox": [ 89, 568, 379, 579 ], "spans": [ { "bbox": [ 89, 568, 379, 579 ], "type": "text", "content": "明确进程和程序的联系和区别，理解进程并发执行的具体含义。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 582, 505, 610 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 116, 583, 505, 594 ], "spans": [ { "bbox": [ 116, 583, 505, 594 ], "type": "text", "content": "（3）通过 Linux 管道通信机制、消息队列通信机制、共享内存通信机制的使用，加深", "score": 1.0 } ] }, { "bbox": [ 89, 599, 253, 610 ], "spans": [ { "bbox": [ 89, 599, 253, 610 ], "type": "text", "content": "对不同类型的进程通信方式的理解。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 613, 449, 625 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 114, 613, 451, 626 ], "spans": [ { "bbox": [ 114, 613, 451, 626 ], "type": "text", "content": "（4）通过对linux的Posix 信号量的应用，加深对信号量同步机制的理解。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 629, 436, 641 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 115, 629, 437, 642 ], "spans": [ { "bbox": [ 115, 629, 437, 642 ], "type": "text", "content": "（5）请根据自身情况，进一步阅读分析相关系统调用的内核源码实现。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 652, 168, 665 ], "type": "title", "angle": 0, "index": 20, "lines": [ { "bbox": [ 108, 652, 168, 665 ], "spans": [ { "bbox": [ 108, 652, 168, 665 ], "type": "text", "content": "2. 设计内容", "score": 1.0 } ] } ] }, { "bbox": [ 86, 677, 505, 704 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 674, 506, 692 ], "spans": [ { "bbox": [ 114, 674, 506, 692 ], "type": "text", "content": "（1）熟悉 linux 常用命令：pwd，useradd，passwd, who, ps, pstree, kill, top, ls, cd, mkdir,", "score": 1.0 } ] }, { "bbox": [ 87, 692, 250, 706 ], "spans": [ { "bbox": [ 87, 692, 250, 706 ], "type": "text", "content": "rmdir, cp, rm, mv, cat, more, grep 等。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 707, 243, 719 ], "type": "title", "angle": 0, "index": 22, "lines": [ { "bbox": [ 114, 706, 245, 721 ], "spans": [ { "bbox": 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"page_idx": 44 }, { "para_blocks": [ { "bbox": [ 86, 72, 506, 101 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 89, 73, 506, 85 ], "spans": [ { "bbox": [ 89, 73, 506, 85 ], "type": "text", "content": "而父进程则等待子进程结束，然后再等待接收下一条命令。如果接收到的命令为exit，则父", "score": 1.0 } ] }, { "bbox": [ 88, 89, 483, 101 ], "spans": [ { "bbox": [ 88, 89, 483, 101 ], "type": "text", "content": "进程结束；如果接收到的命令是无效命令，则显示“Command not found”，继续等待。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 104, 252, 116 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 103, 253, 118 ], "spans": [ { "bbox": [ 114, 103, 253, 118 ], "type": "text", "content": "（3） 实现一个管道通信程序：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 119, 507, 195 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 111, 121, 505, 131 ], "spans": [ { "bbox": [ 111, 121, 505, 131 ], "type": "text", "content": "由父进程创建一个管道，然后再创建 3个子进程，并由这三个子进程利用管道与父进程", "score": 1.0 } ] }, { "bbox": [ 89, 136, 505, 148 ], "spans": [ { 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"sender的消息，将消息显示在终端屏幕上，直至收到内容为“end”的消息为止，此时，它", "score": 1.0 } ] }, { "bbox": [ 89, 307, 505, 320 ], "spans": [ { "bbox": [ 89, 307, 505, 320 ], "type": "text", "content": "向 sender 发送一个应答消息“over”，结束程序的运行。使用无名信号量实现两个线程之间", "score": 1.0 } ] }, { "bbox": [ 88, 322, 159, 336 ], "spans": [ { "bbox": [ 88, 322, 159, 336 ], "type": "text", "content": "的同步与互斥。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 338, 389, 350 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 114, 338, 390, 351 ], "spans": [ { "bbox": [ 114, 338, 390, 351 ], "type": "text", "content": "（5）利用 linux的共享内存通信机制实现两个进程间的通信：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 353, 506, 444 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 110, 354, 505, 366 ], "spans": [ { "bbox": [ 110, 354, 505, 366 ], "type": "text", "content": "编写程序sender，它创建一个共享内存，然后等待用户通过终端输入一串字符，并将这", "score": 1.0 } ] }, { "bbox": [ 89, 370, 505, 381 ], "spans": [ { "bbox": [ 89, 370, 505, 381 ], "type": "text", "content": "串字符通过共享内存发送给 receiver；最后，它等待 receiver 的应答，收到应答消息后，将", "score": 1.0 } ] }, { "bbox": [ 89, 386, 500, 396 ], "spans": [ { "bbox": [ 89, 386, 500, 396 ], "type": "text", "content": "接收到的应答信息显示在终端屏幕上，删除共享内存，结束程序的运行。编写receiver 程序，", "score": 1.0 } ] }, { "bbox": [ 89, 401, 505, 413 ], "spans": [ { "bbox": [ 89, 401, 505, 413 ], "type": "text", "content": "它通过共享内存接收来自 sender 的消息，将消息显示在终端屏幕上，然后再通过该共享内", "score": 1.0 } ] }, { "bbox": [ 89, 417, 505, 428 ], "spans": [ { "bbox": [ 89, 417, 505, 428 ], "type": "text", "content": "存向sender发送一个应答消息“over”，结束程序的运行。使用有名信号量或 System V 信号", "score": 1.0 } ] }, { "bbox": [ 89, 432, 306, 444 ], "spans": [ { "bbox": [ 89, 432, 306, 444 ], "type": "text", "content": "量实现两个进程对共享内存的互斥及同步使用。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 454, 226, 467 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 455, 226, 467 ], "spans": [ { "bbox": [ 109, 455, 226, 467 ], "type": "text", "content": "3. 学时安排（共 6学时）", "score": 1.0 } ] } ] }, { "bbox": [ 108, 486, 169, 498 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 486, 170, 499 ], "spans": [ { "bbox": [ 109, 486, 170, 499 ], "type": "text", "content": "4．开发平台", "score": 1.0 } ] } ] }, { "bbox": [ 129, 509, 309, 523 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 129, 507, 311, 523 ], "spans": [ { "bbox": [ 129, 507, 311, 523 ], "type": "text", "content": "Linux 环境，gcc，gdb，vim 或 gedit 等。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 533, 146, 544 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 107, 531, 148, 547 ], "spans": [ { "bbox": [ 107, 531, 148, 547 ], "type": "text", "content": "5. 思考", "score": 1.0 } ] } ] }, { "bbox": [ 86, 555, 505, 755 ], "type": "list", "angle": 0, "index": 23, "blocks": [ { "bbox": [ 107, 555, 458, 568 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 556, 458, 569 ], "spans": [ { "bbox": [ 109, 556, 458, 569 ], "type": "text", "content": "（1）OS向用户提供的命令接口、图形接口和程序接口分别适用于哪些场合？", "score": 1.0 } ] } ] }, { "bbox": [ 86, 571, 505, 599 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 571, 506, 584 ], "spans": [ { "bbox": [ 109, 571, 506, 584 ], "type": "text", "content": "（2）系统调用和用户自己编制的子函数有什么区别？通常操作系统提供的 API与系统调", "score": 1.0 } ] }, { "bbox": [ 89, 588, 191, 599 ], "spans": [ { "bbox": [ 89, 588, 191, 599 ], "type": "text", "content": "用有什么联系和区别？", "score": 1.0 } ] } ] }, { "bbox": [ 107, 602, 306, 614 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 110, 602, 307, 615 ], "spans": [ { "bbox": [ 110, 602, 307, 615 ], "type": "text", "content": "（3）进程和程序有何联系，又有哪些区别？", "score": 1.0 } ] } ] }, { "bbox": [ 107, 618, 358, 630 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 618, 359, 632 ], "spans": [ { "bbox": [ 110, 618, 359, 632 ], "type": "text", "content": "（4）一个进程从出生到终止，其状态会经历哪些变化？", "score": 1.0 } ] } ] }, { "bbox": [ 108, 634, 285, 645 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 109, 634, 286, 647 ], "spans": [ { "bbox": [ 109, 634, 286, 647 ], "type": "text", "content": "（5）用户可如何取得进程的控制信息？", "score": 1.0 } ] } ] }, { "bbox": [ 107, 650, 402, 661 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 649, 403, 663 ], "spans": [ { "bbox": [ 109, 649, 403, 663 ], "type": "text", "content": "（6）当首次将CPU调度给子进程时，它将从哪里开始执行指令？", "score": 1.0 } ] } ] }, { "bbox": [ 86, 665, 504, 692 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 666, 505, 678 ], "spans": [ { "bbox": [ 109, 666, 505, 678 ], "type": "text", "content": "（7）虽然父子进程可以完全并发执行，但在 Linux中，创建子进程成功之后，通常让子", "score": 1.0 } ] }, { "bbox": [ 89, 682, 284, 692 ], "spans": [ { "bbox": [ 89, 682, 284, 692 ], "type": "text", "content": "进程优先获得CPU，这种做法有什么好处？", "score": 1.0 } ] } ] }, { "bbox": [ 108, 696, 264, 708 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 110, 697, 264, 708 ], "spans": [ { "bbox": [ 110, 697, 264, 708 ], "type": "text", "content": "（8）僵尸进程通常是如何形成的？", "score": 1.0 } ] } ] }, { "bbox": [ 107, 712, 500, 724 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 110, 712, 501, 724 ], "spans": [ { "bbox": [ 110, 712, 501, 724 ], "type": "text", "content": "（9）对一个应用，如果用多个进程的并发执行来实现，与单个进程来实现有什么不同？", "score": 1.0 } ] } ] }, { "bbox": [ 108, 727, 311, 740 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 110, 728, 312, 741 ], "spans": [ { "bbox": [ 110, 728, 312, 741 ], "type": "text", "content": "（10）有名管道和无名管道之间有什么不同？", "score": 1.0 } ] } ] }, { "bbox": [ 108, 743, 311, 755 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 109, 743, 312, 756 ], "spans": [ { "bbox": [ 109, 743, 312, 756 ], "type": "text", "content": "（11）管道的读写与文件的读写有什么异同？", "score": 1.0 } ] } ] } ], "sub_type": "text" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ 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"score": 1.0 } ] } ] }, { "bbox": [ 113, 185, 198, 199 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 185, 199, 200 ], "spans": [ { "bbox": [ 114, 185, 199, 200 ], "type": "text", "content": "4.2.1 常用命令", "score": 1.0 } ] } ] }, { "bbox": [ 88, 211, 496, 238 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 114, 209, 499, 224 ], "spans": [ { "bbox": [ 114, 209, 499, 224 ], "type": "text", "content": "pwd, passwd, who, ps, pstree, kill, top, ls, cd, mkdir, rmdir, cp, rm, mv, cat, more, grep 等。", "score": 1.0 } ] }, { "bbox": [ 89, 225, 200, 238 ], "spans": [ { "bbox": [ 89, 225, 200, 238 ], "type": "text", "content": "自行查阅相关资料学习。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 248, 268, 262 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 247, 270, 264 ], "spans": [ { "bbox": [ 114, 247, 270, 264 ], "type": "text", "content": "4.2.2 Linux 的在线帮助 man", "score": 1.0 } ] } ] }, { "bbox": [ 86, 272, 502, 300 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 110, 273, 503, 285 ], "spans": [ { "bbox": [ 110, 273, 503, 285 ], "type": "text", "content": "Linux提供了丰富的帮助手册，当你需要查看某个命令的参数时不必到处上网查找，只", "score": 1.0 } ] }, { "bbox": [ 89, 288, 294, 301 ], "spans": [ { "bbox": [ 89, 288, 294, 301 ], "type": "text", "content": "要 man（man 为 manual 的简写）一下即可。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 311, 171, 323 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 108, 311, 172, 325 ], "spans": [ { "bbox": [ 108, 311, 172, 325 ], "type": "text", "content": "1. 简单范例", "score": 1.0 } ] } ] }, { "bbox": [ 87, 334, 498, 363 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 333, 499, 349 ], "spans": [ { "bbox": [ 109, 333, 499, 349 ], "type": "text", "content": "例如，如果你不清楚 pwd 命令的用法，你可以在命令提示符下直接输入命令：man pwd，", "score": 1.0 } ] }, { "bbox": [ 89, 349, 265, 362 ], "spans": [ { "bbox": [ 89, 349, 265, 362 ], "type": "text", "content": "马上就会有pwd的详细资料提供给你：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 365, 158, 378 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 108, 364, 160, 380 ], "spans": [ { "bbox": [ 108, 364, 160, 380 ], "type": "text", "content": "PWD（1）", "score": 1.0 } ] } ] }, { "bbox": [ 239, 366, 323, 378 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 239, 365, 324, 379 ], "spans": [ { "bbox": [ 239, 365, 324, 379 ], "type": "text", "content": "User commands", "score": 1.0 } ] } ] }, { "bbox": [ 395, 366, 433, 379 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 393, 364, 436, 382 ], "spans": [ { "bbox": [ 393, 364, 436, 382 ], "type": "text", "content": "Date(1)", "score": 1.0 } ] } ] }, { "bbox": [ 108, 381, 143, 392 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 108, 381, 143, 395 ], "spans": [ { "bbox": [ 108, 381, 143, 395 ], "type": "text", "content": "NAME", "score": 1.0 } ] } ] }, { "bbox": [ 108, 397, 348, 410 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 108, 396, 348, 412 ], "spans": [ { "bbox": [ 108, 396, 348, 412 ], "type": "text", "content": "pwd - print name of current/working directory", "score": 1.0 } ] } ] }, { "bbox": [ 108, 412, 165, 424 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 108, 412, 166, 428 ], "spans": [ { "bbox": [ 108, 412, 166, 428 ], "type": "text", "content": "SYNOPSIS", "score": 1.0 } ] } ] }, { "bbox": [ 108, 428, 173, 440 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 107, 428, 174, 442 ], "spans": [ { "bbox": [ 107, 428, 174, 442 ], "type": "text", "content": "pwd [OPTION]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 444, 183, 455 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 110, 444, 184, 459 ], "spans": [ { "bbox": [ 110, 444, 184, 459 ], "type": "text", "content": "DESCRIPTION", "score": 1.0 } ] } ] }, { "bbox": [ 86, 460, 505, 503 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 108, 459, 506, 473 ], "spans": [ { "bbox": [ 108, 459, 506, 473 ], "type": "text", "content": "NOTE: your shell may have its own version of pwd which will supercede the version", "score": 1.0 } ] }, { "bbox": [ 87, 474, 506, 488 ], "spans": [ { "bbox": [ 87, 474, 506, 488 ], "type": "text", "content": "described here. Please refer to your shell's documentation for details about the", "score": 1.0 } ] }, { "bbox": [ 88, 491, 193, 503 ], "spans": [ { "bbox": [ 88, 491, 193, 503 ], "type": "text", "content": "options it supports.", "score": 1.0 } ] } ] }, { "bbox": [ 107, 507, 407, 518 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 108, 505, 409, 521 ], "spans": [ { "bbox": [ 108, 505, 409, 521 ], "type": "text", "content": "Print the full filename of the current working directory.", "score": 1.0 } ] } ] }, { "bbox": [ 105, 523, 130, 533 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 105, 520, 132, 536 ], "spans": [ { "bbox": [ 105, 520, 132, 536 ], "type": "text", "content": "--help", "score": 1.0 } ] } ] }, { "bbox": [ 107, 538, 246, 550 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 109, 537, 248, 551 ], "spans": [ { "bbox": [ 109, 537, 248, 551 ], "type": "text", "content": "display this help and exit", "score": 1.0 } ] } ] }, { "bbox": [ 105, 555, 141, 564 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 106, 555, 142, 565 ], "spans": [ { "bbox": [ 106, 555, 142, 565 ], "type": "text", "content": "--version", "score": 1.0 } ] } ] }, { "bbox": [ 107, 569, 295, 580 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 108, 568, 296, 581 ], "spans": [ { "bbox": [ 108, 568, 296, 581 ], "type": "text", "content": "output version information and exit", "score": 1.0 } ] } ] }, { "bbox": [ 108, 584, 156, 595 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 108, 584, 157, 598 ], "spans": [ { "bbox": [ 108, 584, 157, 598 ], "type": "text", "content": "AUTHOR", "score": 1.0 } ] } ] }, { "bbox": [ 107, 600, 234, 612 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 108, 597, 236, 615 ], "spans": [ { "bbox": [ 108, 597, 236, 615 ], "type": "text", "content": "Written by Jim Meyering.", "score": 1.0 } ] } ] }, { "bbox": [ 108, 615, 207, 627 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 109, 615, 207, 629 ], "spans": [ { "bbox": [ 109, 615, 207, 629 ], "type": "text", "content": "REPORTING BUGS", "score": 1.0 } ] } ] }, { "bbox": [ 107, 631, 313, 643 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 108, 629, 314, 645 ], "spans": [ { "bbox": [ 108, 629, 314, 645 ], "type": "text", "content": "Report bugs to .", "score": 1.0 } ] } ] }, { "bbox": [ 108, 646, 174, 657 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 109, 646, 174, 661 ], "spans": [ { "bbox": [ 109, 646, 174, 661 ], "type": "text", "content": "COPYRIGHT", "score": 1.0 } ] } ] }, { "bbox": [ 107, 662, 355, 675 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 108, 661, 358, 677 ], "spans": [ { "bbox": [ 108, 661, 161, 677 ], "type": "text", "content": "Copyright", "score": 1.0 }, { "bbox": [ 161, 663, 170, 672 ], "type": "inline_equation", "content": "©", "score": 0.52 }, { "bbox": [ 170, 661, 358, 677 ], "type": "text", "content": "2004 Free Software Foundation, Inc.", "score": 1.0 } ] } ] }, { "bbox": [ 86, 677, 504, 705 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 88, 677, 506, 692 ], "spans": [ { "bbox": [ 88, 677, 506, 692 ], "type": "text", "content": "This is free software; see the source for copying conditions. There is NO warranty;", "score": 1.0 } ] }, { "bbox": [ 88, 693, 429, 706 ], "spans": [ { "bbox": [ 88, 693, 429, 706 ], "type": "text", "content": "not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.", "score": 1.0 } ] } ] }, { "bbox": [ 108, 709, 164, 720 ], "type": "title", "angle": 0, "index": 32, "lines": [ { "bbox": [ 108, 708, 166, 724 ], "spans": [ { "bbox": [ 108, 708, 166, 724 ], "type": "text", "content": "SEE ALSO", "score": 1.0 } ] } ] }, { "bbox": [ 86, 724, 505, 752 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 108, 724, 506, 738 ], "spans": [ { "bbox": [ 108, 724, 506, 738 ], "type": "text", "content": "The full documentation for pwd is maintained as a Texinfo manual. If the info", "score": 1.0 } ] }, { "bbox": [ 88, 740, 432, 753 ], "spans": [ { "bbox": [ 88, 740, 432, 753 ], "type": "text", "content": "and pwd programs are properly installed at your site, the command", "score": 1.0 } ] } ] }, { "bbox": [ 108, 756, 206, 767 ], "type": "text", "angle": 0, "index": 34, "lines": [ { "bbox": [ 109, 755, 207, 770 ], "spans": [ { "bbox": [ 109, 755, 207, 770 ], "type": "text", "content": "info coreutils pwd", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 46 }, { "para_blocks": [ { "bbox": [ 108, 74, 349, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 108, 72, 351, 87 ], "spans": [ { "bbox": [ 108, 72, 351, 87 ], "type": "text", "content": "should give you access to the complete manual.", "score": 1.0 } ] } ] }, { "bbox": [ 108, 111, 205, 125 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 111, 205, 127 ], "spans": [ { "bbox": [ 108, 111, 205, 127 ], "type": "text", "content": "2. man page 说明", "score": 1.0 } ] } ] }, { "bbox": [ 108, 135, 282, 148 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 135, 283, 148 ], "spans": [ { "bbox": [ 110, 135, 283, 148 ], "type": "text", "content": "前面的范例中，第一行名字后的数字：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 151, 250, 272 ], "type": "list", "angle": 0, "index": 12, "blocks": [ { "bbox": [ 108, 151, 188, 163 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 150, 188, 164 ], "spans": [ { "bbox": [ 110, 150, 188, 164 ], "type": "text", "content": "\"1\"表示用户命令", "score": 1.0 } ] } ] }, { "bbox": [ 108, 166, 188, 178 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 165, 188, 179 ], "spans": [ { "bbox": [ 110, 165, 188, 179 ], "type": "text", "content": "\"2\"表示系统调用", "score": 1.0 } ] } ] }, { "bbox": [ 108, 182, 209, 194 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 182, 210, 195 ], "spans": [ { "bbox": [ 110, 182, 210, 195 ], "type": "text", "content": "\"3\"表示C语言库函数", "score": 1.0 } ] } ] }, { "bbox": [ 108, 197, 219, 209 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 110, 197, 220, 211 ], "spans": [ { "bbox": [ 110, 197, 220, 211 ], "type": "text", "content": "\"4\"表示设备或特殊文件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 213, 219, 225 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 110, 213, 219, 226 ], "spans": [ { "bbox": [ 110, 213, 219, 226 ], "type": "text", "content": "\"5\"表示文件格式和规则", "score": 1.0 } ] } ] }, { "bbox": [ 108, 229, 198, 241 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 110, 229, 198, 242 ], "spans": [ { "bbox": [ 110, 229, 198, 242 ], "type": "text", "content": "\"6\"表示游戏及其他", "score": 1.0 } ] } ] }, { "bbox": [ 108, 244, 230, 256 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 244, 230, 257 ], "spans": [ { "bbox": [ 110, 244, 230, 257 ], "type": "text", "content": "\"7\"表示宏、包及其他杂项", "score": 1.0 } ] } ] }, { "bbox": [ 108, 260, 250, 272 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 260, 251, 273 ], "spans": [ { "bbox": [ 110, 260, 251, 273 ], "type": "text", "content": "\"8\"表示系统管理员相关的命令", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 290, 503, 333 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 110, 291, 499, 303 ], "spans": [ { "bbox": [ 110, 291, 499, 303 ], "type": "text", "content": "可见，man不仅可以查询命令，还可以查询系统调用、C语言库函数、配置文件的格式、", "score": 1.0 } ] }, { "bbox": [ 89, 307, 505, 319 ], "spans": [ { "bbox": [ 89, 307, 505, 319 ], "type": "text", "content": "系统管理员可用的管理命令等。值得注意的是man是按照手册的章节号的顺序进行搜索的，", "score": 1.0 } ] }, { "bbox": [ 88, 322, 118, 336 ], "spans": [ { "bbox": [ 88, 322, 118, 336 ], "type": "text", "content": "比如：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 339, 160, 350 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 113, 337, 162, 353 ], "spans": [ { "bbox": [ 113, 337, 162, 353 ], "type": "text", "content": "man sleep", "score": 1.0 } ] } ] }, { "bbox": [ 108, 354, 484, 366 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 108, 351, 487, 370 ], "spans": [ { "bbox": [ 108, 351, 487, 370 ], "type": "text", "content": "只会显示 sleep 命令的手册，如果想查看库函数 sleep，就要输入使用 man 3 sleep。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 370, 403, 382 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 109, 366, 405, 386 ], "spans": [ { "bbox": [ 109, 366, 405, 386 ], "type": "text", "content": "若想知道 sleep 系统调用需要哪些头文件，则要输入 man 2 sleep", "score": 1.0 } ] } ] }, { "bbox": [ 108, 400, 264, 413 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 399, 265, 415 ], "spans": [ { "bbox": [ 109, 399, 265, 415 ], "type": "text", "content": "通常，man page 大致分几个部分：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 416, 321, 428 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 108, 417, 321, 429 ], "spans": [ { "bbox": [ 108, 417, 140, 429 ], "type": "text", "content": "NAME", "score": 1.0 }, { "bbox": [ 195, 417, 321, 428 ], "type": "text", "content": "简短的命令、数据名称说明", "score": 1.0 } ] } ] }, { "bbox": [ 108, 432, 283, 444 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 108, 431, 283, 446 ], "spans": [ { "bbox": [ 108, 431, 154, 446 ], "type": "text", "content": "SYNOPSIS", "score": 1.0 }, { "bbox": [ 188, 431, 283, 444 ], "type": "text", "content": "简短的命令语法简介", "score": 1.0 } ] } ] }, { "bbox": [ 108, 447, 367, 460 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 110, 447, 368, 460 ], "spans": [ { "bbox": [ 110, 447, 368, 460 ], "type": "text", "content": "DESCRIPTION 较为完整的说明，这部分最好仔细看看、", "score": 1.0 } ] } ] }, { "bbox": [ 108, 462, 411, 475 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 108, 462, 412, 477 ], "spans": [ { "bbox": [ 108, 463, 152, 477 ], "type": "text", "content": "OPTIONS", "score": 1.0 }, { "bbox": [ 185, 462, 412, 476 ], "type": "text", "content": "针对 SYNOPSIS部分中，列举说明所有可用的参数", "score": 1.0 } ] } ] }, { "bbox": [ 87, 478, 501, 506 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 110, 479, 501, 491 ], "spans": [ { "bbox": [ 110, 479, 167, 491 ], "type": "text", "content": "COMMANDS", "score": 1.0 }, { "bbox": [ 186, 479, 501, 490 ], "type": "text", "content": "当这个程序（软件）在执行的时候，可以在此程序（软件）中发出的", "score": 1.0 } ] }, { "bbox": [ 87, 491, 114, 509 ], "spans": [ { "bbox": [ 87, 491, 114, 509 ], "type": "text", "content": "命令", "score": 1.0 } ] } ] }, { "bbox": [ 108, 509, 426, 522 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 108, 509, 427, 523 ], "spans": [ { "bbox": [ 108, 509, 135, 523 ], "type": "text", "content": "FILES", "score": 1.0 }, { "bbox": [ 183, 509, 427, 522 ], "type": "text", "content": "这个程序或数据所使用、参考或连接的某些参考说明", "score": 1.0 } ] } ] }, { "bbox": [ 108, 525, 370, 537 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 108, 524, 371, 539 ], "spans": [ { "bbox": [ 108, 525, 152, 539 ], "type": "text", "content": "SEE ALSO", "score": 1.0 }, { "bbox": [ 188, 524, 371, 538 ], "type": "text", "content": "与这个命令或数据相关的其他参考说明、", "score": 1.0 } ] } ] }, { "bbox": [ 108, 540, 282, 553 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 109, 540, 283, 554 ], "spans": [ { "bbox": [ 109, 541, 152, 554 ], "type": "text", "content": "EXAMPLE", "score": 1.0 }, { "bbox": [ 188, 540, 283, 553 ], "type": "text", "content": "一些可以参考的范例", "score": 1.0 } ] } ] }, { "bbox": [ 108, 556, 282, 568 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 108, 555, 283, 570 ], "spans": [ { "bbox": [ 108, 556, 137, 570 ], "type": "text", "content": "BUGS", "score": 1.0 }, { "bbox": [ 196, 555, 283, 570 ], "type": "text", "content": "是否有相关的错误", "score": 1.0 } ] } ] }, { "bbox": [ 108, 595, 286, 608 ], "type": "title", "angle": 0, "index": 27, "lines": [ { "bbox": [ 107, 593, 287, 608 ], "spans": [ { "bbox": [ 107, 593, 287, 608 ], "type": "text", "content": "3. man page 中可以使用的常用按键", "score": 1.0 } ] } ] }, { "bbox": [ 108, 618, 212, 630 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 109, 618, 214, 632 ], "spans": [ { "bbox": [ 109, 618, 214, 632 ], "type": "text", "content": "在man中的按键使用：", "score": 1.0 } ] } ] }, { "bbox": [ 108, 634, 246, 646 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 109, 632, 248, 648 ], "spans": [ { "bbox": [ 109, 632, 145, 648 ], "type": "text", "content": "空格键", "score": 1.0 }, { "bbox": [ 193, 633, 248, 647 ], "type": "text", "content": "向下翻一页", "score": 1.0 } ] } ] }, { "bbox": [ 108, 650, 243, 662 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 107, 649, 245, 665 ], "spans": [ { "bbox": [ 107, 649, 167, 665 ], "type": "text", "content": "[Page Down]", "score": 1.0 }, { "bbox": [ 190, 649, 245, 664 ], "type": "text", "content": "向下翻一页", "score": 1.0 } ] } ] }, { "bbox": [ 108, 666, 241, 678 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 108, 665, 242, 682 ], "spans": [ { "bbox": [ 108, 665, 154, 682 ], "type": "text", "content": "[Page Up]", "score": 1.0 }, { "bbox": [ 188, 665, 242, 678 ], "type": "text", "content": "向上翻一页", "score": 1.0 } ] } ] }, { "bbox": [ 108, 682, 232, 693 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 108, 680, 233, 697 ], "spans": [ { "bbox": [ 108, 680, 145, 697 ], "type": "text", "content": "[Home]", "score": 1.0 }, { "bbox": [ 188, 680, 233, 694 ], "type": "text", "content": "到第一页", "score": 1.0 } ] } ] }, { "bbox": [ 108, 697, 238, 709 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 107, 695, 239, 713 ], "spans": [ { "bbox": [ 107, 695, 136, 713 ], "type": "text", "content": "[End]", "score": 1.0 }, { "bbox": [ 184, 696, 239, 709 ], "type": "text", "content": "到最后一页", "score": 1.0 } ] } ] }, { "bbox": [ 108, 712, 458, 724 ], "type": "text", "angle": 0, "index": 34, "lines": [ { "bbox": [ 107, 710, 459, 728 ], "spans": [ { "bbox": [ 107, 710, 140, 728 ], "type": "text", "content": "/word", "score": 1.0 }, { "bbox": [ 182, 711, 459, 726 ], "type": "text", "content": "向下搜索 word 字符串，如果要搜索 date 的话，就输入/date", "score": 1.0 } ] } ] }, { "bbox": [ 108, 728, 285, 740 ], "type": "text", "angle": 0, "index": 35, "lines": [ { "bbox": [ 108, 724, 286, 743 ], "spans": [ { "bbox": [ 108, 724, 141, 743 ], "type": "text", "content": "?word", "score": 1.0 }, { "bbox": [ 184, 727, 286, 741 ], "type": "text", "content": "向上搜索word字符串", "score": 1.0 } ] } ] }, { "bbox": [ 108, 743, 502, 756 ], "type": "text", "angle": 0, "index": 36, "lines": [ { "bbox": [ 108, 742, 504, 759 ], "spans": [ { "bbox": [ 108, 742, 128, 759 ], "type": "text", "content": "n,N", "score": 1.0 }, { "bbox": [ 183, 743, 504, 756 ], "type": "text", "content": "使用/或?来搜索字符串时，可以用n来继续下一个搜索（不论是/还是?），", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 47 }, { "para_blocks": [ { "bbox": [ 171, 72, 315, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 173, 72, 316, 86 ], "spans": [ { "bbox": [ 173, 72, 316, 86 ], "type": "text", "content": "可以使用N 来进行“反向”搜索。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 88, 504, 117 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 89, 506, 101 ], "spans": [ { "bbox": [ 110, 89, 506, 101 ], "type": "text", "content": "举例来说，我以/date 搜索 date 字符串，那么可以用 n继续往下查询，用 N 往上查询。", "score": 1.0 } ] }, { "bbox": [ 88, 104, 440, 116 ], "spans": [ { "bbox": [ 88, 104, 440, 116 ], "type": "text", "content": "若以?date 向上查询date字符串，可以用n继续 “向上”查询，用N反向查询", "score": 1.0 } ] } ] }, { "bbox": [ 108, 120, 262, 132 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 117, 262, 135 ], "spans": [ { "bbox": [ 108, 121, 118, 135 ], "type": "text", "content": "q", "score": 1.0 }, { "bbox": [ 162, 117, 262, 135 ], "type": "text", "content": "结束并退出 man page", "score": 1.0 } ] } ] }, { "bbox": [ 107, 142, 282, 155 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 108, 142, 282, 157 ], "spans": [ { "bbox": [ 108, 142, 282, 157 ], "type": "text", "content": "4. 互联网上的在线 Linux man 手册", "score": 1.0 } ] } ] }, { "bbox": [ 107, 166, 444, 179 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 166, 444, 180 ], "spans": [ { "bbox": [ 110, 166, 444, 180 ], "type": "text", "content": "即使不在 Linux 下，也可以通过某些网站在线查询某个 Linux 的命令，如：", "score": 1.0 } ] } ] }, { "bbox": [ 121, 182, 269, 195 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 123, 180, 268, 196 ], "spans": [ { "bbox": [ 123, 180, 268, 196 ], "type": "text", "content": "http://www.linuxmanpages.com/", "score": 1.0 } ] } ] }, { "bbox": [ 107, 197, 465, 210 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 108, 195, 466, 212 ], "spans": [ { "bbox": [ 108, 195, 466, 212 ], "type": "text", "content": "在这里有非常全的 Linux 的 man 信息，你可以分 1－8 来查看相应的 manual 。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 221, 247, 233 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 220, 247, 235 ], "spans": [ { "bbox": [ 114, 220, 247, 235 ], "type": "text", "content": "4.2.3 vi 和 vim 编辑器", "score": 1.0 } ] } ] }, { "bbox": [ 108, 252, 196, 264 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 108, 250, 196, 266 ], "spans": [ { "bbox": [ 108, 250, 196, 266 ], "type": "text", "content": "1. vi 和 vim 简介", "score": 1.0 } ] } ] }, { "bbox": [ 86, 275, 506, 335 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 275, 505, 288 ], "spans": [ { "bbox": [ 109, 275, 505, 288 ], "type": "text", "content": "在计算机系统中，编辑文本文件是用户经常要进行的操作。所谓文本文件指的是由", "score": 1.0 } ] }, { "bbox": [ 88, 292, 505, 303 ], "spans": [ { "bbox": [ 88, 292, 505, 303 ], "type": "text", "content": "ASCII码字符构成的文件。vi 编辑器是 Unix/Linux 系统提供的文本编辑器，用于创建和修", "score": 1.0 } ] }, { "bbox": [ 89, 307, 501, 319 ], "spans": [ { "bbox": [ 89, 307, 501, 319 ], "type": "text", "content": "改文本文件。vi 编辑器与其他字处理软件不同，它不包含任何格式方面的信息，如粗体、", "score": 1.0 } ] }, { "bbox": [ 89, 322, 180, 335 ], "spans": [ { "bbox": [ 89, 322, 180, 335 ], "type": "text", "content": "居中或者下划线等。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 338, 508, 396 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 110, 339, 509, 349 ], "spans": [ { "bbox": [ 110, 339, 509, 349 ], "type": "text", "content": "vi编辑器是一个全屏幕编辑器，用户可以在整个文档范围内自由移动光标进行编辑操作。", "score": 1.0 } ] }, { "bbox": [ 88, 354, 505, 365 ], "spans": [ { "bbox": [ 88, 354, 505, 365 ], "type": "text", "content": "vi编辑器中有100多个命令可供用户使用，提供了丰富的编辑功能，当然对于学习使用者来", "score": 1.0 } ] }, { "bbox": [ 89, 370, 505, 380 ], "spans": [ { "bbox": [ 89, 370, 505, 380 ], "type": "text", "content": "说也是个挑战。但是不必灰心，因为只有少数一些命令是必须使用，或者使用频繁的，所以", "score": 1.0 } ] }, { "bbox": [ 89, 385, 411, 397 ], "spans": [ { "bbox": [ 89, 385, 411, 397 ], "type": "text", "content": "只要熟练掌握这些常用命令就可以完成大部分文本文件的编辑任务了。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 400, 506, 444 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 110, 401, 505, 413 ], "spans": [ { "bbox": [ 110, 401, 505, 413 ], "type": "text", "content": "vim 可以当做 vi 的升级版，vi 的命令几乎都可以在 vim 上使用。Vim 会依据文件扩展", "score": 1.0 } ] }, { "bbox": [ 89, 416, 506, 428 ], "spans": [ { "bbox": [ 89, 416, 506, 428 ], "type": "text", "content": "名或文件的开头信息来判断文件内容，而自动执行该程序的语法判断，再以颜色来显示程序", "score": 1.0 } ] }, { "bbox": [ 89, 433, 326, 444 ], "spans": [ { "bbox": [ 89, 433, 326, 444 ], "type": "text", "content": "代码和一般信息。因此 vim用于程序编辑更加方便。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 446, 506, 476 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 110, 447, 506, 460 ], "spans": [ { "bbox": [ 110, 447, 506, 460 ], "type": "text", "content": "在系统提示符（$、#）下，输入：vi <文件名>，vi可以自动载入所要编辑的文件或创", "score": 1.0 } ] }, { "bbox": [ 89, 463, 248, 476 ], "spans": [ { "bbox": [ 89, 463, 248, 476 ], "type": "text", "content": "建一个新文件（若该文件不存在）。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 486, 215, 498 ], "type": "title", "angle": 0, "index": 14, "lines": [ { "bbox": [ 108, 486, 215, 500 ], "spans": [ { "bbox": [ 108, 486, 215, 500 ], "type": "text", "content": "2. vi 的三种工作模式", "score": 1.0 } ] } ] }, { "bbox": [ 107, 509, 389, 522 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 109, 509, 388, 522 ], "spans": [ { "bbox": [ 109, 509, 388, 522 ], "type": "text", "content": "vi编辑器有三种工作模式：一般模式、编辑模式和命令模式：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 524, 505, 569 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 525, 506, 537 ], "spans": [ { "bbox": [ 114, 525, 506, 537 ], "type": "text", "content": "（1）一般模式。以 vi 打开一个文件就直接进入一般模式了(这是默认的模式)。在这个", "score": 1.0 } ] }, { "bbox": [ 89, 541, 505, 553 ], "spans": [ { "bbox": [ 89, 541, 505, 553 ], "type": "text", "content": "模式中， 你可以使用『上下左右』按键来移动光标，你可以使用『删除字符』戒『删除整", "score": 1.0 } ] }, { "bbox": [ 89, 557, 426, 568 ], "spans": [ { "bbox": [ 89, 557, 426, 568 ], "type": "text", "content": "行』来处理文件内容， 也可以使用『复制、贴贴』来处理你的文件数据。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 571, 473, 584 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 110, 571, 474, 584 ], "spans": [ { "bbox": [ 110, 571, 474, 584 ], "type": "text", "content": "即在一般模式中可以进行删除、复制、粘贴等动作，但却无法编辑文件的内容。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 587, 504, 647 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 115, 587, 503, 600 ], "spans": [ { "bbox": [ 115, 587, 503, 600 ], "type": "text", "content": "（2）编辑模式。在一般模式下，按下『i, I, o, O, a, A, r, R』等任何一个字母后就会进入", "score": 1.0 } ] }, { "bbox": [ 89, 603, 504, 615 ], "spans": [ { "bbox": [ 89, 603, 504, 615 ], "type": "text", "content": "编辑模式。通常，在按下这些字母后，在画面的左下方会出现『 INSERT 或 REPLACE 』的", "score": 1.0 } ] }, { "bbox": [ 89, 618, 504, 631 ], "spans": [ { "bbox": [ 89, 618, 504, 631 ], "type": "text", "content": "字样，此时才可以进行编辑。而要回到一般模式，则必须按下『 ESC 』按键，即可退出编", "score": 1.0 } ] }, { "bbox": [ 89, 634, 200, 646 ], "spans": [ { "bbox": [ 89, 634, 200, 646 ], "type": "text", "content": "辑模式，返回一般模式。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 649, 483, 661 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 110, 650, 483, 662 ], "spans": [ { "bbox": [ 110, 650, 483, 662 ], "type": "text", "content": "而读取、保存、大量字符替换、离开 vi、显示行号等操作也是在该模式下完成的。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 673, 171, 685 ], "type": "title", "angle": 0, "index": 20, "lines": [ { "bbox": [ 108, 672, 172, 687 ], "spans": [ { "bbox": [ 108, 672, 172, 687 ], "type": "text", "content": "3. 使用范例", "score": 1.0 } ] } ] }, { "bbox": [ 108, 696, 166, 708 ], "type": "title", "angle": 0, "index": 21, "lines": [ { "bbox": [ 129, 695, 167, 710 ], "spans": [ { "bbox": [ 129, 695, 167, 710 ], "type": "text", "content": "范例1：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 712, 506, 756 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 115, 712, 499, 724 ], "spans": [ { "bbox": [ 115, 712, 499, 724 ], "type": "text", "content": "（1）在Linux命令行界面下输入命令：vi ccc.c 后便进入vi的一般模式。如图5-1所示，", "score": 1.0 } ] }, { "bbox": [ 88, 729, 505, 740 ], "spans": [ { "bbox": [ 88, 729, 505, 740 ], "type": "text", "content": "vi的界面分为上下两部分，上半部分显示的是文件的实际内容，而下半部，即最下面的一行", "score": 1.0 } ] }, { "bbox": [ 89, 744, 506, 756 ], "spans": [ { "bbox": [ 89, 744, 506, 756 ], "type": "text", "content": "则显示一些状态信息。如果 ccc.c是一个原来不存在的文件，状态行中会显示『“ccc.c” [New", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 48 }, { "para_blocks": [ { "bbox": [ 86, 72, 465, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 88, 73, 465, 85 ], "spans": [ { "bbox": [ 88, 73, 465, 85 ], "type": "text", "content": "File] 』表示它是一个新文件，否则，会显示出被编辑文件的行数、字符数等信息。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 88, 505, 130 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 89, 505, 101 ], "spans": [ { "bbox": [ 114, 89, 505, 101 ], "type": "text", "content": "（2）按 “i”进入编辑模式，此时，状态行中会出现『 INSERT』的字样，便可以开始编", "score": 1.0 } ] }, { "bbox": [ 88, 104, 505, 116 ], "spans": [ { "bbox": [ 88, 104, 505, 116 ], "type": "text", "content": "辑文字了。此时，你输入的除了“ESC”以外的所有信息都被视为文件的内容，比如你可以输", "score": 1.0 } ] }, { "bbox": [ 88, 119, 107, 133 ], "spans": [ { "bbox": [ 88, 119, 107, 133 ], "type": "text", "content": "入：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 107, 136, 237, 195 ], "blocks": [ { "bbox": [ 107, 136, 237, 195 ], "lines": [ { "bbox": [ 107, 136, 237, 195 ], "spans": [ { "bbox": [ 107, 136, 237, 195 ], "type": "text", "content": "include \nmain(){ printf(\"Hello,World!\\n\"); \n}" } ] } ], "index": 3, "angle": 0, "type": "code_body" } ], "index": 3, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 112, 197, 428, 226 ], "type": "list", "angle": 0, "index": 6, "blocks": [ { "bbox": [ 112, 197, 428, 210 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 114, 197, 428, 211 ], "spans": [ { "bbox": [ 114, 197, 428, 211 ], "type": "text", "content": "（3）按“ESC”回到一般模式，此时，状态行中的『 INSERT』不见了。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 212, 379, 226 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 213, 379, 226 ], "spans": [ { "bbox": [ 114, 213, 379, 226 ], "type": "text", "content": "（4）在一般模式中输入“：wq”保存文件的内容并离开vi。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 243, 161, 256 ], "type": "title", "angle": 0, "index": 7, "lines": [ { "bbox": [ 129, 243, 163, 259 ], "spans": [ { "bbox": [ 129, 243, 163, 259 ], "type": "text", "content": "范例 2", "score": 1.0 } ] } ] }, { "bbox": [ 113, 259, 375, 288 ], "type": "list", "angle": 0, "index": 10, "blocks": [ { "bbox": [ 113, 259, 348, 272 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 259, 348, 275 ], "spans": [ { "bbox": [ 114, 259, 348, 275 ], "type": "text", "content": "（1）在 Linux 命令行界面下输入命令： vi file1.txt", "score": 1.0 } ] } ] }, { "bbox": [ 113, 275, 375, 288 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 115, 275, 376, 288 ], "spans": [ { "bbox": [ 115, 275, 376, 288 ], "type": "text", "content": "（2）按 “i”进入编辑模式，输入下列字符，并保存文件。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "type": "code", "bbox": [ 107, 291, 305, 350 ], "blocks": [ { "bbox": [ 107, 291, 305, 350 ], "lines": [ { "bbox": [ 107, 291, 305, 350 ], "spans": [ { "bbox": [ 107, 291, 305, 350 ], "type": "text", "content": "You raise me up, so I can stand on mountains; \nYou raise me up, to walk on stormy seas; \nI am strong, when I am on your shoulders; \nYou raise me up: To more than I can be." } ] } ], "index": 11, "angle": 0, "type": "code_body" } ], "index": 11, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 108, 369, 161, 380 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 129, 368, 163, 383 ], "spans": [ { "bbox": [ 129, 368, 163, 383 ], "type": "text", "content": "范例 3", "score": 1.0 } ] } ] }, { "bbox": [ 108, 384, 362, 396 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 384, 363, 398 ], "spans": [ { "bbox": [ 109, 384, 363, 398 ], "type": "text", "content": "通过vi编辑器编辑一个 systemcall.c文件，其内容如下：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 401, 303, 599 ], "blocks": [ { "bbox": [ 108, 401, 303, 599 ], "lines": [ { "bbox": [ 108, 401, 303, 599 ], "spans": [ { "bbox": [ 108, 401, 303, 599 ], "type": "text", "content": "include \n#include \nint main(){ int fd=0，i; charbuf[10]; fd=open(\"file1.txt\",O_RDONLY); if(fd==-1)printf(\"Cannot open file!\\n\"); while((i=read(fd,buf,sizeof(buf)-1)>0){ buf[i]='\\0'; printf(\"%s\",buf); } \n}" } ] } ], "index": 14, "angle": 0, "type": "code_body" } ], "index": 14, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 113, 602, 379, 631 ], "type": "list", "angle": 0, "index": 17, "blocks": [ { "bbox": [ 113, 602, 246, 614 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 602, 246, 616 ], "spans": [ { "bbox": [ 114, 602, 246, 616 ], "type": "text", "content": "（3）按“ESC”回到一般模式。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 618, 379, 631 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 618, 379, 632 ], "spans": [ { "bbox": [ 114, 618, 379, 632 ], "type": "text", "content": "（4）在一般模式中输入“：wq”保存文件的内容并离开vi。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 641, 235, 655 ], "type": "title", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 642, 235, 655 ], "spans": [ { "bbox": [ 109, 642, 235, 655 ], "type": "text", "content": "4. 一般模式下的常用按键", "score": 1.0 } ] } ] }, { "bbox": [ 113, 665, 180, 677 ], "type": "title", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 665, 180, 679 ], "spans": [ { "bbox": [ 114, 665, 180, 679 ], "type": "text", "content": "（1）光标移动", "score": 1.0 } ] } ] }, { "bbox": [ 107, 680, 479, 709 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 109, 682, 479, 692 ], "spans": [ { "bbox": [ 109, 682, 479, 692 ], "type": "text", "content": "vi可以直接用键盘上的光标键来上下左右移动，但正规的 vi是用小写英文字母 。", "score": 1.0 } ] }, { "bbox": [ 108, 697, 342, 709 ], "spans": [ { "bbox": [ 108, 697, 342, 709 ], "type": "text", "content": "h、j、k、l，分别控制光标左、下、上、右移一格。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 711, 282, 724 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 109, 712, 283, 726 ], "spans": [ { "bbox": [ 109, 712, 283, 726 ], "type": "text", "content": "按 Ctrl+B：屏幕往后移动一页。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 727, 282, 740 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 109, 726, 283, 741 ], "spans": [ { "bbox": [ 109, 726, 283, 741 ], "type": "text", "content": "按Ctrl+F：屏幕往前移动一页。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 743, 250, 755 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 110, 743, 251, 756 ], "spans": [ { "bbox": [ 110, 743, 251, 756 ], "type": "text", "content": "按Ctrl+U：屏幕往后移动半页。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 49 }, { "para_blocks": [ { "bbox": [ 108, 73, 251, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 73, 252, 87 ], "spans": [ { "bbox": [ 109, 73, 252, 87 ], "type": "text", "content": "按 Ctrl+D：屏幕往前移动半页。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 88, 295, 102 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 89, 295, 102 ], "spans": [ { "bbox": [ 110, 89, 295, 102 ], "type": "text", "content": "按 0 (数字零)：移动文章的开头。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 104, 266, 117 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 103, 267, 118 ], "spans": [ { "bbox": [ 109, 103, 267, 118 ], "type": "text", "content": "按 G：移动到文章的最后。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 119, 298, 132 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 119, 299, 133 ], "spans": [ { "bbox": [ 109, 119, 299, 133 ], "type": "text", "content": "按 w：光标跳到下个单词的开头。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 135, 262, 148 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 136, 263, 148 ], "spans": [ { "bbox": [ 110, 136, 263, 148 ], "type": "text", "content": "按 e：光标跳到下个单词的字尾。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 151, 262, 163 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 150, 264, 164 ], "spans": [ { "bbox": [ 110, 150, 264, 164 ], "type": "text", "content": "按 b：光标回到上个单词的开头。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 166, 286, 179 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 110, 166, 286, 179 ], "spans": [ { "bbox": [ 110, 166, 286, 179 ], "type": "text", "content": "按 $：移到光标所在行的行尾。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 182, 283, 194 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 182, 284, 195 ], "spans": [ { "bbox": [ 109, 182, 284, 195 ], "type": "text", "content": "按 ^：移到该行第一个非空白的字符。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 197, 276, 211 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 110, 198, 276, 211 ], "spans": [ { "bbox": [ 110, 198, 276, 211 ], "type": "text", "content": "按 0：移到该行的开头位置。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 213, 349, 226 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 212, 349, 227 ], "spans": [ { "bbox": [ 109, 212, 349, 227 ], "type": "text", "content": "按 #：移到该行的第#个位置，例：51、121。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 113, 228, 159, 241 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 227, 160, 243 ], "spans": [ { "bbox": [ 114, 227, 160, 243 ], "type": "text", "content": "（2）删除", "score": 1.0 } ] } ] }, { "bbox": [ 107, 244, 364, 258 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 243, 364, 258 ], "spans": [ { "bbox": [ 108, 243, 364, 258 ], "type": "text", "content": "x：每按一次删除光标所在位置的后面一个字符。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 107, 260, 383, 273 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 260, 385, 275 ], "spans": [ { "bbox": [ 109, 260, 385, 275 ], "type": "text", "content": "#x：例如，6x 表删除光标所在位置的后面 6 个字符。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 107, 275, 381, 288 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 108, 275, 382, 289 ], "spans": [ { "bbox": [ 108, 275, 382, 289 ], "type": "text", "content": "X：大字的 X，每按一次删除光标所在位置的前面一个字符。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 290, 363, 304 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 108, 290, 364, 305 ], "spans": [ { "bbox": [ 108, 290, 364, 305 ], "type": "text", "content": "#X：例如，20X 表删除光标所在位置的前面 20 个字符。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 306, 255, 320 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 109, 306, 255, 321 ], "spans": [ { "bbox": [ 109, 306, 255, 321 ], "type": "text", "content": "dd：删除光标所在行。[超常用]", "score": 1.0 } ] } ] }, { "bbox": [ 107, 322, 425, 336 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 108, 322, 427, 337 ], "spans": [ { "bbox": [ 108, 322, 427, 337 ], "type": "text", "content": "#dd：例如，6dd 表删除从光标所在的该行往下数 6 行之文字。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 338, 181, 350 ], "type": "title", "angle": 0, "index": 18, "lines": [ { "bbox": [ 108, 337, 182, 351 ], "spans": [ { "bbox": [ 108, 337, 182, 351 ], "type": "text", "content": "(3)复制 与粘贴", "score": 1.0 } ] } ] }, { "bbox": [ 107, 354, 337, 366 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 108, 354, 339, 366 ], "spans": [ { "bbox": [ 108, 354, 339, 366 ], "type": "text", "content": "yw：将光标所在处到字尾的字符复制到缓冲区中。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 370, 253, 382 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 108, 369, 254, 383 ], "spans": [ { "bbox": [ 108, 369, 254, 383 ], "type": "text", "content": "yy：复制光标所在行。[超常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 384, 423, 398 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 108, 384, 424, 399 ], "spans": [ { "bbox": [ 108, 384, 424, 399 ], "type": "text", "content": "#yy：如：6yy 表示拷贝从光标所在的该行往下数 6 行之文字。[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 400, 295, 413 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 108, 400, 296, 413 ], "spans": [ { "bbox": [ 108, 400, 296, 413 ], "type": "text", "content": "p：将已复制的内容粘贴在光标后的位置", "score": 1.0 } ] } ] }, { "bbox": [ 108, 415, 295, 428 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 109, 416, 295, 428 ], "spans": [ { "bbox": [ 109, 416, 295, 428 ], "type": "text", "content": "P：将已复制的内容粘贴在光标前的位置", "score": 1.0 } ] } ] }, { "bbox": [ 108, 431, 143, 444 ], "type": "title", "angle": 0, "index": 24, "lines": [ { "bbox": [ 107, 430, 146, 446 ], "spans": [ { "bbox": [ 107, 430, 146, 446 ], "type": "text", "content": "(4)替换", "score": 1.0 } ] } ] }, { "bbox": [ 108, 447, 273, 460 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 108, 446, 274, 461 ], "spans": [ { "bbox": [ 108, 446, 274, 461 ], "type": "text", "content": "r： 取代光标所在处的字符：[常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 463, 245, 475 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 109, 462, 246, 476 ], "spans": [ { "bbox": [ 109, 462, 246, 476 ], "type": "text", "content": "R：取代字符直到按 Esc为止。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 478, 176, 491 ], "type": "title", "angle": 0, "index": 27, "lines": [ { "bbox": [ 108, 478, 177, 491 ], "spans": [ { "bbox": [ 108, 478, 177, 491 ], "type": "text", "content": "(5)撤销和重做", "score": 1.0 } ] } ] }, { "bbox": [ 108, 493, 446, 507 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 108, 493, 448, 508 ], "spans": [ { "bbox": [ 108, 493, 448, 508 ], "type": "text", "content": "u：假如您误操作一个指令，可以马上按 u，可撤销前一个操作。[超常用]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 509, 268, 522 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 109, 510, 270, 521 ], "spans": [ { "bbox": [ 109, 510, 270, 521 ], "type": "text", "content": "U：撤销当前行上最近的所有操作。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 525, 222, 537 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 109, 524, 223, 538 ], "spans": [ { "bbox": [ 109, 524, 223, 538 ], "type": "text", "content": "ctrl+r：重做上一个操作。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 540, 280, 553 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 108, 540, 282, 553 ], "spans": [ { "bbox": [ 108, 540, 282, 553 ], "type": "text", "content": ".： 点号可以重复执行上一次的指令。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 556, 143, 569 ], "type": "title", "angle": 0, "index": 32, "lines": [ { "bbox": [ 107, 555, 146, 571 ], "spans": [ { "bbox": [ 107, 555, 146, 571 ], "type": "text", "content": "(6)更改", "score": 1.0 } ] } ] }, { "bbox": [ 108, 571, 279, 584 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 109, 572, 280, 584 ], "spans": [ { "bbox": [ 109, 572, 280, 584 ], "type": "text", "content": "cw：更改光标所在处的字到字尾$处。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 587, 268, 600 ], "type": "text", "angle": 0, "index": 34, "lines": [ { "bbox": [ 109, 586, 269, 602 ], "spans": [ { "bbox": [ 109, 586, 269, 602 ], "type": "text", "content": "c#w：例如，c3w 代表更改 3 个字。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 602, 202, 615 ], "type": "title", "angle": 0, "index": 35, "lines": [ { "bbox": [ 114, 602, 203, 616 ], "spans": [ { "bbox": [ 114, 602, 203, 616 ], "type": "text", "content": "(7)切换到编辑模式", "score": 1.0 } ] } ] }, { "bbox": [ 108, 618, 399, 740 ], "type": "list", "angle": 0, "index": 44, "blocks": [ { "bbox": [ 108, 618, 286, 631 ], "type": "text", "angle": 0, "index": 36, "lines": [ { "bbox": [ 109, 618, 286, 631 ], "spans": [ { "bbox": [ 109, 618, 286, 631 ], "type": "text", "content": "i ：进入插入模式，在当前光标前插入", "score": 1.0 } ] } ] }, { "bbox": [ 108, 634, 276, 646 ], "type": "text", "angle": 0, "index": 37, "lines": [ { "bbox": [ 109, 634, 277, 647 ], "spans": [ { "bbox": [ 109, 634, 277, 647 ], "type": "text", "content": "I ：进入插入模式，在当前行首插入", "score": 1.0 } ] } ] }, { "bbox": [ 108, 650, 283, 661 ], "type": "text", "angle": 0, "index": 38, "lines": [ { "bbox": [ 108, 650, 284, 662 ], "spans": [ { "bbox": [ 108, 650, 284, 662 ], "type": "text", "content": "a：进入插入模式，在当前光标后插入", "score": 1.0 } ] } ] }, { "bbox": [ 108, 666, 280, 677 ], "type": "text", "angle": 0, "index": 39, "lines": [ { "bbox": [ 108, 666, 280, 677 ], "spans": [ { "bbox": [ 108, 666, 280, 677 ], "type": "text", "content": "A ：进入插入模式，在当前行尾插入", "score": 1.0 } ] } ] }, { "bbox": [ 108, 681, 305, 693 ], "type": "text", "angle": 0, "index": 40, "lines": [ { "bbox": [ 109, 681, 306, 694 ], "spans": [ { "bbox": [ 109, 681, 306, 694 ], "type": "text", "content": "o：进入插入模式，在当前行之下新开一行", "score": 1.0 } ] } ] }, { "bbox": [ 108, 696, 306, 708 ], "type": "text", "angle": 0, "index": 41, "lines": [ { "bbox": [ 109, 697, 307, 709 ], "spans": [ { "bbox": [ 109, 697, 307, 709 ], "type": "text", "content": "O：进入插入模式，在当前行之上新开一行", "score": 1.0 } ] } ] }, { "bbox": [ 108, 712, 261, 724 ], "type": "text", "angle": 0, "index": 42, "lines": [ { "bbox": [ 108, 712, 262, 724 ], "spans": [ { "bbox": [ 108, 712, 262, 724 ], "type": "text", "content": "r：进入替换模式，替换当前字符", "score": 1.0 } ] } ] }, { "bbox": [ 108, 727, 399, 740 ], "type": "text", "angle": 0, "index": 43, "lines": [ { "bbox": [ 109, 727, 401, 741 ], "spans": [ { "bbox": [ 109, 727, 401, 741 ], "type": "text", "content": "R：进入替换模式，替换当前字符及其后的字符，直至按 ESC键", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 751, 235, 763 ], "type": "title", "angle": 0, "index": 45, "lines": [ { "bbox": [ 108, 751, 235, 765 ], "spans": [ { "bbox": [ 108, 751, 235, 765 ], "type": "text", "content": "5. 命令模式下的常用命令", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 50 }, { "para_blocks": [ { "bbox": [ 107, 72, 490, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 73, 490, 86 ], "spans": [ { "bbox": [ 109, 73, 490, 86 ], "type": "text", "content": "在一般模式下，按“:”便可切换到命令模式，然后可以使用下述命令模式下的命令：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 88, 441, 101 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 107, 88, 443, 103 ], "spans": [ { "bbox": [ 107, 88, 443, 103 ], "type": "text", "content": "q 命令：在没有任何修改操作发生的情况下，该命令可以退出 vi 编辑器。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 104, 305, 116 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 104, 307, 117 ], "spans": [ { "bbox": [ 109, 104, 307, 117 ], "type": "text", "content": "q!命令：不保存文件，强制退出 vi编辑器。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 119, 199, 132 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 108, 119, 201, 132 ], "spans": [ { "bbox": [ 108, 119, 201, 132 ], "type": "text", "content": "w命令：保存文件。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 135, 298, 148 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 108, 135, 298, 148 ], "spans": [ { "bbox": [ 108, 135, 298, 148 ], "type": "text", "content": "wq命令：保存文件，然后退出vi编辑器", "score": 1.0 } ] } ] }, { "bbox": [ 107, 151, 357, 163 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 150, 358, 164 ], "spans": [ { "bbox": [ 109, 150, 358, 164 ], "type": "text", "content": "w[文件名] 命令：将编辑后的文件另存到指定文件中。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 165, 489, 179 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 166, 490, 180 ], "spans": [ { "bbox": [ 109, 166, 490, 180 ], "type": "text", "content": "r[文件名] 命令：将指定文件的内容读入，并添加到当前文件光标所在的位置后面。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 190, 259, 202 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 189, 260, 204 ], "spans": [ { "bbox": [ 114, 189, 260, 204 ], "type": "text", "content": "4.2.4 Linux 环境下 C 编程", "score": 1.0 } ] } ] }, { "bbox": [ 108, 221, 186, 233 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 220, 188, 235 ], "spans": [ { "bbox": [ 109, 220, 188, 235 ], "type": "text", "content": "1. GCC 编译器", "score": 1.0 } ] } ] }, { "bbox": [ 113, 244, 176, 258 ], "type": "title", "angle": 0, "index": 10, "lines": [ { "bbox": [ 114, 243, 176, 260 ], "spans": [ { "bbox": [ 114, 243, 176, 260 ], "type": "text", "content": "（1）gcc 概述", "score": 1.0 } ] } ] }, { "bbox": [ 86, 259, 505, 288 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 108, 259, 506, 273 ], "spans": [ { "bbox": [ 108, 259, 506, 273 ], "type": "text", "content": "GCC 是 linux 下最常用的编译器，也能运行在 unix、solaris、windows 等下，支持多种语", "score": 1.0 } ] }, { "bbox": [ 89, 275, 327, 288 ], "spans": [ { "bbox": [ 89, 275, 169, 288 ], "type": "text", "content": "言的编译，如C、", "score": 1.0 }, { "bbox": [ 169, 276, 188, 287 ], "type": "inline_equation", "content": "{ \\mathsf { C } } { + } { + }", "score": 0.86 }, { "bbox": [ 189, 275, 327, 288 ], "type": "text", "content": "、Object C 等语言编写的程序。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 290, 508, 350 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 291, 511, 303 ], "spans": [ { "bbox": [ 108, 291, 264, 303 ], "type": "text", "content": "gcc对文件的处理需要经过预处理", "score": 1.0 }, { "bbox": [ 264, 292, 272, 302 ], "type": "inline_equation", "content": "- >", "score": 0.6 }, { "bbox": [ 273, 291, 294, 303 ], "type": "text", "content": "编译-", "score": 1.0 }, { "bbox": [ 294, 292, 302, 302 ], "type": "inline_equation", "content": "- >", "score": 0.56 }, { "bbox": [ 302, 291, 321, 303 ], "type": "text", "content": "汇编", "score": 1.0 }, { "bbox": [ 322, 292, 331, 302 ], "type": "inline_equation", "content": "^ { - > }", "score": 0.53 }, { "bbox": [ 332, 291, 511, 303 ], "type": "text", "content": "链接的步骤，从而产生一个可执行文件。", "score": 1.0 } ] }, { "bbox": [ 89, 307, 504, 319 ], "spans": [ { "bbox": [ 89, 307, 504, 319 ], "type": "text", "content": "预处理阶段主要是在库中寻找头文件，包含到待编译的文件中；编译阶段检查程序的语法；", "score": 1.0 } ] }, { "bbox": [ 89, 323, 504, 334 ], "spans": [ { "bbox": [ 89, 323, 504, 334 ], "type": "text", "content": "汇编阶段将源代码翻译成机器语言；链接阶段将所有的目标代码连接成一个可执行程序。各", "score": 1.0 } ] }, { "bbox": [ 89, 338, 262, 349 ], "spans": [ { "bbox": [ 89, 338, 262, 349 ], "type": "text", "content": "阶段对应不同的文件类型，具体如下：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 354, 223, 366 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 108, 352, 223, 370 ], "spans": [ { "bbox": [ 108, 352, 135, 370 ], "type": "text", "content": "file.c", "score": 1.0 }, { "bbox": [ 160, 353, 223, 367 ], "type": "text", "content": "c 程序源文件", "score": 1.0 } ] } ] }, { "bbox": [ 107, 369, 257, 381 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 108, 368, 257, 384 ], "spans": [ { "bbox": [ 108, 368, 132, 384 ], "type": "text", "content": "file.i", "score": 1.0 }, { "bbox": [ 164, 369, 257, 382 ], "type": "text", "content": "c程序预处理后文件", "score": 1.0 } ] } ] }, { "bbox": [ 107, 384, 383, 397 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 108, 384, 384, 399 ], "spans": [ { "bbox": [ 108, 384, 154, 399 ], "type": "text", "content": "file.cxx", "score": 1.0 }, { "bbox": [ 155, 386, 170, 396 ], "type": "inline_equation", "content": "{ \\mathsf { C } } { \\mathsf { + + } }", "score": 0.87 }, { "bbox": [ 171, 384, 384, 399 ], "type": "text", "content": "程序源文件，也可以是 file.cc / file.cpp / file.c++", "score": 1.0 } ] } ] }, { "bbox": [ 107, 400, 262, 412 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 108, 400, 262, 414 ], "spans": [ { "bbox": [ 108, 400, 134, 414 ], "type": "text", "content": "file.ii", "score": 1.0 }, { "bbox": [ 161, 401, 178, 412 ], "type": "inline_equation", "content": "{ \\mathsf { C } } { \\mathsf { + + } }", "score": 0.88 }, { "bbox": [ 178, 401, 262, 412 ], "type": "text", "content": "程序预处理后文件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 416, 218, 428 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 108, 414, 219, 431 ], "spans": [ { "bbox": [ 108, 414, 135, 431 ], "type": "text", "content": "file.h", "score": 1.0 }, { "bbox": [ 162, 417, 187, 428 ], "type": "inline_equation", "content": "{ \\mathsf { c } } / { \\mathsf { c } } { + } { + }", "score": 0.87 }, { "bbox": [ 188, 415, 219, 429 ], "type": "text", "content": "头文件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 431, 225, 444 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 108, 430, 226, 446 ], "spans": [ { "bbox": [ 108, 430, 133, 446 ], "type": "text", "content": "file.s", "score": 1.0 }, { "bbox": [ 160, 431, 226, 444 ], "type": "text", "content": "汇编程序文件", "score": 1.0 } ] } ] }, { "bbox": [ 108, 447, 227, 460 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 108, 446, 227, 462 ], "spans": [ { "bbox": [ 108, 446, 135, 462 ], "type": "text", "content": "file.o", "score": 1.0 }, { "bbox": [ 163, 446, 227, 461 ], "type": "text", "content": "目标代码文件", "score": 1.0 } ] } ] }, { "bbox": [ 113, 462, 204, 475 ], "type": "title", "angle": 0, "index": 20, "lines": [ { "bbox": [ 114, 461, 205, 477 ], "spans": [ { "bbox": [ 114, 461, 205, 477 ], "type": "text", "content": "（2）GCC 使用格式：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 478, 218, 491 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 108, 477, 220, 493 ], "spans": [ { "bbox": [ 108, 477, 220, 493 ], "type": "text", "content": "gcc [参数选项] [文件名]", "score": 1.0 } ] } ] }, { "bbox": [ 108, 493, 262, 506 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 110, 494, 263, 506 ], "spans": [ { "bbox": [ 110, 494, 263, 506 ], "type": "text", "content": "其中文件名是要编译的文件名称。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 509, 277, 522 ], "type": "title", "angle": 0, "index": 23, "lines": [ { "bbox": [ 114, 508, 279, 523 ], "spans": [ { "bbox": [ 114, 508, 279, 523 ], "type": "text", "content": "（3）GCC遵循的部分后缀越大规则：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 524, 505, 552 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 110, 524, 506, 539 ], "spans": [ { "bbox": [ 110, 524, 506, 539 ], "type": "text", "content": "当调用gcc时，gcc根据待编译文件的扩展名（后缀）自动识别文件的类别，并调用对应", "score": 1.0 } ] }, { "bbox": [ 110, 540, 342, 553 ], "spans": [ { "bbox": [ 110, 540, 342, 553 ], "type": "text", "content": "的编译器。Gcc遵循的部分后缀约定规则如表所示：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 106, 554, 487, 733 ], "blocks": [ { "bbox": [ 106, 554, 487, 733 ], "lines": [ { "bbox": [ 106, 554, 487, 733 ], "spans": [ { "bbox": [ 106, 554, 487, 733 ], "type": "table", "html": "
后缀约定规则
.cC语言源代码文件
.a由目标文件构成的档案库文件
.C .cc .cxxC++源代码文件
.h程序包含的头文件
.i已经预处理过的C源代码文件
.ii已经预处理过的C++源代码文件
.mObjective-C源代码文件
.o编译后的目标文件
.s汇编语言源代码文件
.S经过预编译的汇编语言源代码文件
", "image_path": "4d7da42029b734d47a6d2ae6b049a39e16785ea00b3a621db5bacb8c39747492.jpg" } ] } ], "index": 25, "angle": 0, "type": "table_body" } ], "index": 25 }, { "bbox": [ 113, 749, 214, 761 ], "type": "title", "angle": 0, "index": 26, "lines": [ { "bbox": [ 114, 747, 215, 763 ], "spans": [ { "bbox": [ 114, 747, 215, 763 ], "type": "text", "content": "（4）GCC的参数说明：", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 51 }, { "para_blocks": [ { "bbox": [ 107, 73, 271, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 73, 272, 85 ], "spans": [ { "bbox": [ 109, 73, 272, 85 ], "type": "text", "content": "GCC 参数很多，最常用的参数如下：", "score": 1.0 } ] } ] }, { "bbox": [ 128, 88, 505, 195 ], "type": "list", 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"index": 15, "blocks": [ { "bbox": [ 135, 197, 270, 210 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 136, 197, 270, 211 ], "spans": [ { "bbox": [ 136, 200, 151, 211 ], "type": "text", "content": "-w", "score": 1.0 }, { "bbox": [ 205, 197, 270, 211 ], "type": "text", "content": "取消所有警告", "score": 1.0 } ] } ] }, { "bbox": [ 135, 213, 293, 226 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 136, 212, 293, 227 ], "spans": [ { "bbox": [ 136, 213, 154, 227 ], "type": "text", "content": "-W", "score": 1.0 }, { "bbox": [ 207, 212, 293, 227 ], "type": "text", "content": "给出更详细的警告", "score": 1.0 } ] } ] }, { "bbox": [ 135, 228, 464, 242 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 135, 227, 465, 246 ], "spans": [ { "bbox": [ 135, 227, 180, 246 ], "type": "text", "content": "-O [num]", "score": 1.0 }, { "bbox": [ 201, 227, 465, 243 ], "type": "text", "content": "优化，可以指定 0-3 作为优化级别，级别 0 表示没有优化", "score": 1.0 } ] } ] }, { "bbox": [ 129, 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504, 321 ], "spans": [ { "bbox": [ 135, 307, 163, 321 ], "type": "text", "content": "-L dir", "score": 1.0 }, { "bbox": [ 195, 307, 504, 320 ], "type": "text", "content": "将 dir 目录加到搜索-lname 选项指定的函数库文件的目录列表中去，", "score": 1.0 } ] }, { "bbox": [ 130, 322, 445, 335 ], "spans": [ { "bbox": [ 130, 322, 445, 335 ], "type": "text", "content": "并优先于gcc缺省的搜索目录，有多个-L 选项时，按照出现顺序搜索", "score": 1.0 } ] } ] }, { "bbox": [ 129, 338, 509, 382 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 137, 337, 511, 351 ], "spans": [ { "bbox": [ 137, 338, 170, 351 ], "type": "text", "content": "-lname", "score": 1.0 }, { "bbox": [ 204, 337, 511, 350 ], "type": "text", "content": "在链接时使用函数库libname.a，链接程序在-Ldir 指定的目录和/lib、", "score": 1.0 } ] }, { "bbox": [ 129, 354, 489, 366 ], "spans": [ { "bbox": [ 129, 354, 489, 366 ], "type": "text", "content": "/usr/lib目录下寻找该库文件，在没有使用-static选项时，如果发现共享函数库", "score": 1.0 } ] }, { "bbox": [ 129, 370, 337, 381 ], "spans": [ { "bbox": [ 129, 370, 337, 381 ], "type": "text", "content": "libname.so，则使用 libname.so 进行动态链接", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 135, 384, 431, 396 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 136, 384, 432, 400 ], "spans": [ { "bbox": [ 136, 384, 161, 400 ], "type": "text", "content": "-fPIC", "score": 1.0 }, { "bbox": [ 199, 384, 432, 397 ], "type": "text", "content": "产生位置无关的目标代码，可用于构造共享函数库", "score": 1.0 } ] } ] }, { "bbox": [ 135, 401, 302, 412 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 136, 400, 301, 415 ], "spans": [ { "bbox": [ 136, 400, 167, 415 ], "type": "text", "content": "-static", "score": 1.0 }, { "bbox": [ 195, 400, 301, 414 ], "type": "text", "content": "禁止与共享函数库链接", "score": 1.0 } ] } ] }, { "bbox": [ 135, 416, 344, 428 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 136, 415, 345, 430 ], "spans": [ { "bbox": [ 136, 415, 173, 430 ], "type": "text", "content": "-shared", "score": 1.0 }, { "bbox": [ 202, 416, 345, 428 ], "type": "text", "content": "尽量与共享函数库链接（默认）", "score": 1.0 } ] } ] }, { "bbox": [ 113, 446, 188, 459 ], "type": "title", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 447, 189, 460 ], "spans": [ { "bbox": [ 114, 447, 189, 460 ], "type": "text", "content": "（5）简单范例1", "score": 1.0 } ] } ] }, { "bbox": [ 117, 462, 424, 490 ], "type": "list", "angle": 0, "index": 22, "blocks": [ { "bbox": [ 117, 462, 424, 475 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 119, 461, 426, 477 ], "spans": [ { "bbox": [ 119, 461, 426, 477 ], "type": "text", "content": "1）按“vi 编辑器”的简单范例 1，先通过 vi 编辑器编辑好文件 ccc.c。", "score": 1.0 } ] } ] }, { "bbox": [ 118, 478, 379, 490 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 120, 478, 379, 491 ], "spans": [ { "bbox": [ 120, 478, 379, 491 ], "type": "text", "content": "2）使用Linux命令行界面，在命令提示符后，输入命令：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 120, 496, 169, 505 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 121, 495, 170, 507 ], "spans": [ { "bbox": [ 121, 495, 170, 507 ], "type": "text", "content": "gcc ccc.c", "score": 1.0 } ] } ] }, { "bbox": [ 125, 509, 498, 521 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 127, 508, 500, 523 ], "spans": [ { "bbox": [ 127, 508, 500, 523 ], "type": "text", "content": "功能：对源程序 ccc.c进行编译链接，产生对应的可执行文件，文件名缺省为：a.out。", "score": 1.0 } ] } ] }, { "bbox": [ 121, 524, 381, 537 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 123, 525, 381, 538 ], "spans": [ { "bbox": [ 123, 525, 381, 538 ], "type": "text", "content": "也可以通过选项-o在编译命令中指定可执行文件名，如：", "score": 1.0 } ] } ] }, { "bbox": [ 121, 543, 196, 553 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 121, 542, 196, 555 ], "spans": [ { "bbox": [ 121, 542, 196, 555 ], "type": "text", "content": "gcc -o ccc ccc.c", "score": 1.0 } ] } ] }, { "bbox": [ 113, 555, 320, 568 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 114, 555, 320, 570 ], "spans": [ { "bbox": [ 114, 555, 320, 570 ], "type": "text", "content": "将产生可执行文件 ccc，而不是默认的 a.out。", "score": 1.0 } ] } ] }, { "bbox": [ 92, 571, 505, 599 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 119, 570, 506, 585 ], "spans": [ { "bbox": [ 119, 570, 506, 585 ], "type": "text", "content": "3）在命令提示符后，输入命令：./a.out 或 ./ccc 运行当前目录下可执行文件 a.out", "score": 1.0 } ] }, { "bbox": [ 93, 586, 138, 601 ], "spans": [ { "bbox": [ 93, 586, 138, 601 ], "type": "text", "content": "（或ccc）。", "score": 1.0 } ] } ] }, { "bbox": [ 109, 602, 262, 615 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 112, 603, 263, 615 ], "spans": [ { "bbox": [ 112, 603, 263, 615 ], "type": "text", "content": "上述范例的运行结果如下图所示。", "score": 1.0 } ] } ] }, { "type": "image", "bbox": [ 88, 621, 517, 742 ], "blocks": [ { "bbox": [ 88, 621, 517, 742 ], "lines": [ { "bbox": [ 88, 621, 517, 742 ], "spans": [ { "bbox": [ 88, 621, 517, 742 ], "type": "image", "image_path": "8ed87e5f78e622d01fd77b4113f203bbd7af2478750a827f77d71e61f9b2c529.jpg" } ] } ], "index": 30, "angle": 0, "type": "image_body" } ], "index": 30 }, { "bbox": [ 88, 743, 189, 755 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 89, 744, 190, 756 ], "spans": [ { "bbox": [ 89, 744, 190, 756 ], "type": "text", "content": "证你的理解是否正确。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 52 }, { "para_blocks": [ { "bbox": [ 86, 72, 505, 116 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 120, 74, 505, 84 ], "spans": [ { "bbox": [ 120, 74, 505, 84 ], "type": "text", "content": "3）思考上述程序中文件打开操作和读文件操作到底是谁具体完成的，并用 man查阅", "score": 1.0 } ] }, { "bbox": [ 88, 89, 502, 101 ], "spans": [ { "bbox": [ 88, 89, 502, 101 ], "type": "text", "content": "open，read，printf，了解它们的具体功能、函数参数和返回值等信息，并注意它们属于系", "score": 1.0 } ] }, { "bbox": [ 88, 104, 338, 116 ], "spans": [ { "bbox": [ 88, 104, 338, 116 ], "type": "text", "content": "统调用，还是库函数，以加速对系统调用概念的理解。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 120, 189, 132 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 119, 189, 133 ], "spans": [ { "bbox": [ 114, 119, 189, 133 ], "type": "text", "content": "（7）简单范例 3", "score": 1.0 } ] } ] }, { "bbox": [ 108, 135, 189, 148 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 135, 190, 148 ], "spans": [ { "bbox": [ 109, 135, 190, 148 ], "type": "text", "content": "编译多个源文件。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 151, 379, 163 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 113, 148, 381, 167 ], "spans": [ { "bbox": [ 113, 148, 381, 167 ], "type": "text", "content": "1） 使用 vi/vim 编辑器编写两个文件：message.c，main.c：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 144, 167, 217, 194 ], "blocks": [ { "bbox": [ 144, 167, 217, 194 ], "lines": [ { "bbox": [ 144, 167, 217, 194 ], "spans": [ { "bbox": [ 144, 167, 217, 194 ], "type": "text", "content": "vi message.c \nvi main.c" } ] } ], "index": 5, "angle": 0, "type": "code_body" } ], "index": 5, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 113, 197, 196, 210 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 114, 197, 198, 211 ], "spans": [ { "bbox": [ 114, 197, 198, 211 ], "type": "text", "content": "2）使用 gcc 编译：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 113, 212, 504, 242 ], "blocks": [ { "bbox": [ 113, 212, 504, 242 ], "lines": [ { "bbox": [ 113, 212, 504, 242 ], "spans": [ { "bbox": [ 113, 212, 504, 242 ], "type": "text", "content": "gcc -c message.c //输出message.o文件，是一个已编译的目标代码文件gcc -c main.c //输出main.o文件" } ] } ], "index": 7, "angle": 0, "type": "code_body" } ], "index": 7, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 113, 244, 505, 258 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 243, 506, 259 ], "spans": [ { "bbox": [ 114, 245, 263, 259 ], "type": "text", "content": "gcc -o all main.o message.o", "score": 1.0 }, { "bbox": [ 272, 243, 506, 258 ], "type": "text", "content": "//执行连接阶段的工作，然后生成可执行文件 all", "score": 1.0 } ] } ] }, { "bbox": [ 113, 260, 210, 272 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 260, 211, 273 ], "spans": [ { "bbox": [ 114, 260, 211, 273 ], "type": "text", "content": "3）执行可执行文件：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 130, 276, 153, 288 ], "blocks": [ { "bbox": [ 130, 276, 153, 288 ], "lines": [ { "bbox": [ 130, 276, 153, 288 ], "spans": [ { "bbox": [ 130, 276, 153, 288 ], "type": "text", "content": "./all" } ] } ], "index": 10, "angle": 0, "type": "code_body" } ], "index": 10, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 86, 290, 504, 319 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 109, 290, 505, 305 ], "spans": [ { "bbox": [ 109, 290, 505, 305 ], "type": "text", "content": "注意：：gcc 对如何将多个源文件编译成一个可执行文件有内置的规则，所以前面的多", "score": 1.0 } ] }, { "bbox": [ 89, 307, 241, 319 ], "spans": [ { "bbox": [ 89, 307, 241, 319 ], "type": "text", "content": "个单独步骤可以简化为一个命令：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 102, 322, 253, 336 ], "blocks": [ { "bbox": [ 102, 322, 253, 336 ], "lines": [ { "bbox": [ 102, 322, 253, 336 ], "spans": [ { "bbox": [ 102, 322, 253, 336 ], "type": "text", "content": "gcc -o all message.c main.c" } ] } ], "index": 12, "angle": 0, "type": "code_body" } ], "index": 12, "sub_type": "code", "guess_lang": "batch" }, { "bbox": [ 107, 346, 193, 359 ], "type": "title", "angle": 0, "index": 13, "lines": [ { "bbox": [ 107, 345, 194, 360 ], "spans": [ { "bbox": [ 107, 345, 194, 360 ], "type": "text", "content": "2. gdb 调试工具", "score": 1.0 } ] } ] }, { "bbox": [ 86, 369, 504, 396 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 369, 506, 382 ], "spans": [ { "bbox": [ 109, 369, 314, 382 ], "type": "text", "content": "gdb 是一个 GNU 调试工具，可以调试 C 和", "score": 1.0 }, { "bbox": [ 315, 369, 340, 381 ], "type": "inline_equation", "content": "{ \\mathsf { C } } { \\mathsf { + + } }", "score": 0.87 }, { "bbox": [ 341, 369, 506, 382 ], "type": "text", "content": "程序，其主要功能有：1）监视程序", "score": 1.0 } ] }, { "bbox": [ 89, 384, 308, 396 ], "spans": [ { "bbox": [ 89, 384, 308, 396 ], "type": "text", "content": "中变量的值；2）设置断点；3）单步执行程序。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 400, 504, 428 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 110, 401, 505, 413 ], "spans": [ { "bbox": [ 110, 401, 505, 413 ], "type": "text", "content": "为了能够使用gdb 调试程序，必须在编译时包含调试信息，即使用gcc编译时需要加", "score": 1.0 } ] }, { "bbox": [ 89, 416, 290, 429 ], "spans": [ { "bbox": [ 89, 416, 290, 429 ], "type": "text", "content": "上“-g”选修，如 gcc –g –o test test.c。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 431, 326, 444 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 108, 431, 327, 444 ], "spans": [ { "bbox": [ 108, 431, 327, 444 ], "type": "text", "content": "gdb 命令很多，下面列出一些常用的调试命令：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 447, 213, 460 ], "type": "title", "angle": 0, "index": 17, "lines": [ { "bbox": [ 114, 445, 215, 462 ], "spans": [ { "bbox": [ 114, 445, 215, 462 ], "type": "text", "content": "（1）gdb 启动及退出：", "score": 1.0 } ] } ] }, { "bbox": [ 119, 462, 277, 476 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 120, 461, 278, 477 ], "spans": [ { "bbox": [ 120, 461, 278, 477 ], "type": "text", "content": "1）启动gdb命令：gdb exefilename", "score": 1.0 } ] } ] }, { "bbox": [ 86, 477, 504, 506 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 476, 506, 491 ], "spans": [ { "bbox": [ 114, 476, 506, 491 ], "type": "text", "content": "其中 exefilename 是可执行文件名，如果没有指定运行程序，也可进入 gdb 后再用", "score": 1.0 } ] }, { "bbox": [ 88, 493, 177, 507 ], "spans": [ { "bbox": [ 88, 493, 177, 507 ], "type": "text", "content": "file命令装入文件。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 509, 492, 522 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 113, 508, 494, 523 ], "spans": [ { "bbox": [ 113, 508, 494, 523 ], "type": "text", "content": "gdb 启动成功后，提示符为：（gdb），随后可以输入gdb 命令对程序进行调试。", "score": 1.0 } ] } ] }, { "bbox": [ 116, 525, 259, 538 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 117, 523, 260, 540 ], "spans": [ { "bbox": [ 117, 523, 260, 540 ], "type": "text", "content": "2）退出 gdb 命令：(gdb)quit", "score": 1.0 } ] } ] }, { "bbox": [ 113, 540, 205, 553 ], "type": "title", "angle": 0, "index": 22, "lines": [ { "bbox": [ 114, 539, 205, 554 ], "spans": [ { "bbox": [ 114, 539, 205, 554 ], "type": "text", "content": "（2）断点管理命令：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 555, 181, 568 ], "type": "title", "angle": 0, "index": 23, "lines": [ { "bbox": [ 114, 555, 182, 569 ], "spans": [ { "bbox": [ 114, 555, 182, 569 ], "type": "text", "content": "1）设置断点：", "score": 1.0 } ] } ] }, { "bbox": [ 104, 571, 504, 599 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 127, 571, 505, 584 ], "spans": [ { "bbox": [ 127, 571, 505, 584 ], "type": "text", "content": "break命令（可简写为b）可以用来在调试的程序中设置断点，该命令有如下四种", "score": 1.0 } ] }, { "bbox": [ 103, 585, 135, 602 ], "spans": [ { "bbox": [ 103, 585, 135, 602 ], "type": "text", "content": "形式：", "score": 1.0 } ] } ] }, { "bbox": [ 104, 602, 381, 615 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 104, 602, 382, 617 ], "spans": [ { "bbox": [ 104, 602, 382, 617 ], "type": "text", "content": "(gdb)break line-number 使程序在执行给定行之前停止。", "score": 1.0 } ] } ] }, { "bbox": [ 104, 618, 414, 631 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 105, 618, 416, 633 ], "spans": [ { "bbox": [ 105, 618, 416, 633 ], "type": "text", "content": "(gdb)break function-name 使程序在进入指定的函数之前停止。", "score": 1.0 } ] } ] }, { "bbox": [ 104, 634, 504, 661 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 105, 633, 506, 648 ], "spans": [ { "bbox": [ 105, 633, 506, 648 ], "type": "text", "content": "(gdb)break line-or-function if condition 如果 condition（条件）是真，程序到达", "score": 1.0 } ] }, { "bbox": [ 105, 649, 207, 662 ], "spans": [ { "bbox": [ 105, 649, 207, 662 ], "type": "text", "content": "指定行或函数时停止。", "score": 1.0 } ] } ] }, { "bbox": [ 104, 665, 387, 678 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 105, 664, 388, 679 ], "spans": [ { "bbox": [ 105, 664, 388, 679 ], "type": "text", "content": "(gdb) break routine-name 在指定例程的入口处设置断点", "score": 1.0 } ] } ] }, { "bbox": [ 104, 681, 504, 708 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 107, 682, 505, 692 ], "spans": [ { "bbox": [ 107, 682, 505, 692 ], "type": "text", "content": "如果该程序是由很多原文件构成的，你可以在各个原文件中设置断点，而不是在当前的", "score": 1.0 } ] }, { "bbox": [ 107, 697, 258, 708 ], "spans": [ { "bbox": [ 107, 697, 258, 708 ], "type": "text", "content": "原文件中设置断点，其方法如下：", "score": 1.0 } ] } ] }, { "bbox": [ 104, 713, 287, 725 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 105, 711, 290, 728 ], "spans": [ { "bbox": [ 105, 711, 290, 728 ], "type": "text", "content": "(gdb) break filename:line-number", "score": 1.0 } ] } ] }, { "bbox": [ 104, 728, 299, 740 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 105, 726, 302, 744 ], "spans": [ { "bbox": [ 105, 726, 302, 744 ], "type": "text", "content": "(gdb) break filename:function-name", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 53 }, { "para_blocks": [ { "bbox": [ 113, 72, 223, 85 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 116, 74, 223, 85 ], "spans": [ { "bbox": [ 116, 74, 223, 85 ], "type": "text", "content": "2）从断点处继续执行：", "score": 1.0 } ] } ] }, { "bbox": [ 110, 89, 198, 102 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 110, 88, 198, 105 ], "spans": [ { "bbox": [ 110, 88, 198, 105 ], "type": "text", "content": "(gdb) countinue", "score": 1.0 } ] } ] }, { "bbox": [ 113, 119, 261, 132 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 114, 119, 261, 133 ], "spans": [ { "bbox": [ 114, 119, 261, 133 ], "type": "text", "content": "3）显示当前 gdb 的断点信息：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 135, 202, 149 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 113, 134, 203, 151 ], "spans": [ { "bbox": [ 113, 134, 203, 151 ], "type": "text", "content": "(gdb) info break", "score": 1.0 } ] } ] }, { "bbox": [ 113, 165, 233, 179 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 166, 233, 179 ], "spans": [ { "bbox": [ 114, 166, 233, 179 ], "type": "text", "content": "4）删除指定的某个断点：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 182, 251, 195 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 114, 181, 252, 198 ], "spans": [ { "bbox": [ 114, 181, 252, 198 ], "type": "text", "content": "(gdb) delete breakpoint 1", "score": 1.0 } ] } ] }, { "bbox": [ 113, 197, 456, 210 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 198, 458, 211 ], "spans": [ { "bbox": [ 114, 198, 458, 211 ], "type": "text", "content": "该命令将会删除编号为 1 的断点，如果不带编号参数，将删除所有的断点：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 213, 241, 227 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 113, 211, 243, 228 ], "spans": [ { "bbox": [ 113, 211, 243, 228 ], "type": "text", "content": "(gdb) delete breakpoint", "score": 1.0 } ] } ] }, { "bbox": [ 113, 243, 218, 257 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 245, 218, 257 ], "spans": [ { "bbox": [ 114, 245, 218, 257 ], "type": "text", "content": "5）禁止使用某个断点", "score": 1.0 } ] } ] }, { "bbox": [ 113, 260, 255, 274 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 113, 259, 257, 275 ], "spans": [ { "bbox": [ 113, 259, 257, 275 ], "type": "text", "content": "(gdb) disable breakpoint 1", "score": 1.0 } ] } ] }, { "bbox": [ 113, 275, 210, 287 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 275, 212, 289 ], "spans": [ { "bbox": [ 114, 275, 212, 289 ], "type": "text", "content": "该命令将禁止断点 1", "score": 1.0 } ] } ] }, { "bbox": [ 113, 290, 218, 304 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 290, 218, 305 ], "spans": [ { "bbox": [ 114, 290, 218, 305 ], "type": "text", "content": "6）允许使用某个断点", "score": 1.0 } ] } ] }, { "bbox": [ 113, 306, 253, 321 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 113, 306, 255, 322 ], "spans": [ { "bbox": [ 113, 306, 255, 322 ], "type": "text", "content": "(gdb) enable breakpoint 1", "score": 1.0 } ] } ] }, { "bbox": [ 113, 322, 211, 334 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 114, 322, 212, 336 ], "spans": [ { "bbox": [ 114, 322, 212, 336 ], "type": "text", "content": "该命令将允许断点 1", "score": 1.0 } ] } ] }, { "bbox": [ 113, 337, 313, 350 ], "type": "title", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 338, 313, 351 ], "spans": [ { "bbox": [ 114, 338, 313, 351 ], "type": "text", "content": "7）清除原文件中某一代码行上的所有断点", "score": 1.0 } ] } ] }, { "bbox": [ 113, 354, 218, 367 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 352, 218, 370 ], "spans": [ { "bbox": [ 114, 352, 218, 370 ], "type": "text", "content": "(gdb)clean number", "score": 1.0 } ] } ] }, { "bbox": [ 113, 369, 318, 381 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 114, 369, 319, 383 ], "spans": [ { "bbox": [ 114, 369, 319, 383 ], "type": "text", "content": "注：number 为原文件的某个代码行的行号", "score": 1.0 } ] } ] }, { "bbox": [ 113, 400, 205, 412 ], "type": "title", "angle": 0, "index": 18, "lines": [ { "bbox": [ 114, 400, 205, 414 ], "spans": [ { "bbox": [ 114, 400, 205, 414 ], "type": "text", "content": "（3）显示信息命令：", "score": 1.0 } ] } ] }, { "bbox": [ 121, 416, 196, 428 ], "type": "title", "angle": 0, "index": 19, "lines": [ { "bbox": [ 121, 413, 198, 431 ], "spans": [ { "bbox": [ 121, 413, 198, 431 ], "type": "text", "content": "1）print 命令：", "score": 1.0 } ] } ] }, { "bbox": [ 121, 431, 308, 444 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 122, 431, 309, 445 ], "spans": [ { "bbox": [ 122, 431, 309, 445 ], "type": "text", "content": "利用 print 命令可以检查各个变量的值。", "score": 1.0 } ] } ] }, { "bbox": [ 121, 447, 336, 460 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 121, 445, 336, 464 ], "spans": [ { "bbox": [ 121, 445, 194, 464 ], "type": "text", "content": "(gdb) print p", "score": 1.0 }, { "bbox": [ 220, 446, 336, 461 ], "type": "text", "content": "//(p 为变量名或表达式)", "score": 1.0 } ] } ] }, { "bbox": [ 121, 462, 333, 476 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 122, 461, 334, 476 ], "spans": [ { "bbox": [ 122, 461, 334, 476 ], "type": "text", "content": "(gdb) print 开始表达式@连续内存空间大小", "score": 1.0 } ] } ] }, { "bbox": [ 133, 477, 477, 491 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 135, 478, 478, 491 ], "spans": [ { "bbox": [ 135, 478, 478, 491 ], "type": "text", "content": "打印内存中某一连续内存空间的值，主要用于打印数组类型的表达式的值。", "score": 1.0 } ] } ] }, { "bbox": [ 124, 493, 294, 507 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 124, 493, 295, 507 ], "spans": [ { "bbox": [ 124, 493, 295, 507 ], "type": "text", "content": "(gdb) print 程序中的某一函数调用", "score": 1.0 } ] } ] }, { "bbox": [ 134, 509, 299, 523 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 134, 507, 301, 525 ], "spans": [ { "bbox": [ 134, 507, 301, 525 ], "type": "text", "content": "如：(gdb) print find_entry(1,0)", "score": 1.0 } ] } ] }, { "bbox": [ 129, 539, 342, 553 ], "type": "title", "angle": 0, "index": 26, "lines": [ { "bbox": [ 130, 539, 344, 555 ], "spans": [ { "bbox": [ 130, 539, 344, 555 ], "type": "text", "content": "2）whatis 命令：可以显示某个变量的类型", "score": 1.0 } ] } ] }, { "bbox": [ 129, 555, 289, 569 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 130, 553, 290, 573 ], "spans": [ { "bbox": [ 130, 553, 214, 573 ], "type": "text", "content": "(gdb) whatis p", "score": 1.0 }, { "bbox": [ 225, 555, 290, 571 ], "type": "text", "content": "//(p 为变量)", "score": 1.0 } ] } ] }, { "bbox": [ 129, 571, 195, 585 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 129, 571, 198, 585 ], "spans": [ { "bbox": [ 129, 571, 157, 585 ], "type": "text", "content": "type", "score": 1.0 }, { "bbox": [ 157, 573, 168, 583 ], "type": "inline_equation", "content": "=", "score": 0.78 }, { "bbox": [ 169, 571, 198, 585 ], "type": "text", "content": "int *", "score": 1.0 } ] } ] }, { "bbox": [ 129, 602, 323, 616 ], "type": "title", "angle": 0, "index": 29, "lines": [ { "bbox": [ 129, 601, 323, 618 ], "spans": [ { "bbox": [ 129, 601, 323, 618 ], "type": "text", "content": "3）display 命令：设置要显示的表达式", "score": 1.0 } ] } ] }, { "bbox": [ 129, 618, 464, 632 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 129, 618, 465, 634 ], "spans": [ { "bbox": [ 129, 618, 236, 634 ], "type": "text", "content": "(gdb)display 表达式", "score": 1.0 }, { "bbox": [ 259, 618, 465, 633 ], "type": "text", "content": "//当程序运行到断点时，显示该表达式的值。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 634, 362, 647 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 130, 633, 364, 648 ], "spans": [ { "bbox": [ 130, 633, 364, 648 ], "type": "text", "content": "(gdb)info display：显示所有要显示表达式的值。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 649, 357, 663 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 129, 648, 358, 664 ], "spans": [ { "bbox": [ 129, 648, 358, 664 ], "type": "text", "content": "(gdb)undisplay 表达式：结束已设置的表达式。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 665, 317, 678 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 130, 665, 317, 679 ], "spans": [ { "bbox": [ 130, 665, 317, 679 ], "type": "text", "content": "4）awatch 命令：设置要监视的表达式", "score": 1.0 } ] } ] }, { "bbox": [ 119, 680, 226, 694 ], "type": "text", "angle": 0, "index": 34, "lines": [ { "bbox": [ 119, 679, 226, 696 ], "spans": [ { "bbox": [ 119, 679, 226, 696 ], "type": "text", "content": "(gdb)awatch 表达式", "score": 1.0 } ] } ] }, { "bbox": [ 119, 696, 399, 709 ], "type": "text", "angle": 0, "index": 35, "lines": [ { "bbox": [ 121, 697, 399, 709 ], "spans": [ { "bbox": [ 121, 697, 399, 709 ], "type": "text", "content": "当表达式的值变化或被读取时，程序暂停，显示表达式的值。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 727, 226, 740 ], "type": "title", "angle": 0, "index": 36, "lines": [ { "bbox": [ 115, 727, 226, 741 ], "spans": [ { "bbox": [ 115, 727, 226, 741 ], "type": "text", "content": "（4）程序运行控制命令：", "score": 1.0 } ] } ] }, { "bbox": [ 121, 743, 211, 755 ], "type": "text", "angle": 0, "index": 37, "lines": [ { "bbox": [ 121, 742, 213, 756 ], "spans": [ { "bbox": [ 121, 742, 213, 756 ], "type": "text", "content": "1）run：运行程序", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 54 }, { "para_blocks": [ { "bbox": [ 120, 72, 290, 132 ], "type": "list", "angle": 0, "index": 5, "blocks": [ { "bbox": [ 120, 72, 261, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 123, 74, 261, 85 ], "spans": [ { "bbox": [ 123, 74, 261, 85 ], "type": "text", "content": "2）kill：结束程序的调试运行", "score": 1.0 } ] } ] }, { "bbox": [ 120, 89, 238, 101 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 121, 88, 238, 101 ], "spans": [ { "bbox": [ 121, 88, 238, 101 ], "type": "text", 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"bbox": [ 122, 165, 255, 179 ], "type": "text", "content": "1）file命令：加载调试文件", "score": 1.0 } ] }, { "bbox": [ 135, 181, 190, 195 ], "spans": [ { "bbox": [ 135, 181, 190, 195 ], "type": "text", "content": "file 文件名", "score": 1.0 } ] } ] }, { "bbox": [ 120, 197, 254, 226 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 123, 198, 254, 211 ], "spans": [ { "bbox": [ 123, 198, 254, 211 ], "type": "text", "content": "2）list 命令：列出文件内容", "score": 1.0 } ] }, { "bbox": [ 135, 211, 189, 227 ], "spans": [ { "bbox": [ 135, 211, 189, 227 ], "type": "text", "content": "list [参数]", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 113, 228, 162, 240 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 114, 228, 164, 242 ], "spans": [ { "bbox": [ 114, 228, 164, 242 ], "type": "text", "content": "参数说明：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 243, 387, 257 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 115, 244, 387, 258 ], "spans": [ { "bbox": [ 115, 244, 387, 258 ], "type": "text", "content": "参数为空：从上次显示的最后一行或附近开始，显示 10 行", "score": 1.0 } ] } ] }, { "bbox": [ 113, 259, 291, 272 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 116, 260, 292, 274 ], "spans": [ { "bbox": [ 116, 260, 292, 274 ], "type": "text", "content": "<行号>：从当前文件的该行开始显示", "score": 1.0 } ] } ] }, { "bbox": [ 113, 275, 354, 334 ], "type": "list", "angle": 0, "index": 17, "blocks": [ { "bbox": [ 113, 275, 354, 288 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 116, 275, 354, 289 ], "spans": [ { "bbox": [ 116, 275, 197, 289 ], "type": "text", "content": "<文件名> <行号", "score": 1.0 }, { "bbox": [ 198, 276, 207, 287 ], "type": "inline_equation", "content": ">", "score": 0.7 }, { "bbox": [ 207, 275, 354, 289 ], "type": "text", "content": "：从指定文件的指定行开始显示", "score": 1.0 } ] } ] }, { "bbox": [ 113, 290, 249, 303 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 116, 291, 249, 303 ], "spans": [ { "bbox": [ 116, 291, 155, 303 ], "type": "text", "content": "<函数名", "score": 1.0 }, { "bbox": [ 155, 292, 164, 302 ], "type": "inline_equation", "content": ">", "score": 0.76 }, { "bbox": [ 165, 291, 249, 303 ], "type": "text", "content": "：显示指定的函数", "score": 1.0 } ] } ] }, { "bbox": [ 113, 306, 323, 319 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 116, 306, 323, 320 ], "spans": [ { "bbox": [ 116, 306, 207, 320 ], "type": "text", "content": "<文件名> <函数名", "score": 1.0 }, { "bbox": [ 207, 308, 217, 318 ], "type": "inline_equation", "content": ">", "score": 0.67 }, { "bbox": [ 217, 306, 323, 320 ], "type": "text", "content": "：指定文件的指定函数", "score": 1.0 } ] } ] }, { "bbox": [ 113, 322, 327, 334 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 116, 322, 327, 336 ], "spans": [ { "bbox": [ 116, 322, 146, 336 ], "type": "text", "content": "<行号", "score": 1.0 }, { "bbox": [ 147, 322, 172, 334 ], "type": "inline_equation", "content": "1 > <", "score": 0.8 }, { "bbox": [ 172, 322, 193, 336 ], "type": "text", "content": "<行号", "score": 1.0 }, { "bbox": [ 194, 322, 211, 334 ], "type": "inline_equation", "content": "^ { 2 > }", "score": 0.86 }, { "bbox": [ 211, 322, 327, 336 ], "type": "text", "content": "：从行号 1 显示到行号 2", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 113, 353, 205, 366 ], "type": "title", "angle": 0, "index": 18, "lines": [ { "bbox": [ 114, 353, 205, 367 ], "spans": [ { "bbox": [ 114, 353, 205, 367 ], "type": "text", "content": "（6）堆栈相关命令：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 369, 358, 381 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 368, 360, 384 ], "spans": [ { "bbox": [ 114, 368, 360, 384 ], "type": "text", "content": "1）backtrace 命令：可简写为 bt，显示栈中内容。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 384, 341, 396 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 114, 382, 342, 399 ], "spans": [ { "bbox": [ 114, 382, 165, 399 ], "type": "text", "content": "命令：bt:", "score": 1.0 }, { "bbox": [ 189, 385, 342, 396 ], "type": "text", "content": "显示当前函数调用栈的所有信息。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 400, 428, 412 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 400, 429, 414 ], "spans": [ { "bbox": [ 114, 400, 161, 414 ], "type": "text", "content": "命令：bt", "score": 1.0 }, { "bbox": [ 161, 401, 201, 412 ], "type": "inline_equation", "content": "< \\mathsf { n } > : \\mathsf { n }", "score": 0.68 }, { "bbox": [ 201, 400, 429, 414 ], "type": "text", "content": "是一个正整数，表示只打印栈顶上 n 层的栈信息。", "score": 1.0 } ] } ] }, { "bbox": [ 191, 416, 428, 428 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 192, 416, 430, 428 ], "spans": [ { "bbox": [ 192, 416, 430, 428 ], "type": "text", "content": "n是一个负整数，表示只打印栈底下n 层的栈信息。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 431, 359, 444 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 113, 430, 361, 445 ], "spans": [ { "bbox": [ 113, 430, 361, 445 ], "type": "text", "content": "2）frame命令：可简写为f，显示当前栈层的信息：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 449, 505, 480 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 110, 451, 505, 462 ], "spans": [ { "bbox": [ 110, 451, 505, 462 ], "type": "text", "content": "显示的内容有：栈的层编号，当前的函数名，函数参数值，函数所在文件及行号，函数", "score": 1.0 } ] }, { "bbox": [ 88, 468, 158, 481 ], "spans": [ { "bbox": [ 88, 468, 158, 481 ], "type": "text", "content": "执行到的语句。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 483, 246, 496 ], "type": "title", "angle": 0, "index": 25, "lines": [ { "bbox": [ 114, 481, 248, 498 ], "spans": [ { "bbox": [ 114, 481, 248, 498 ], "type": "text", "content": "info frame（或 info f）：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 502, 505, 550 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 111, 502, 505, 513 ], "spans": [ { "bbox": [ 111, 502, 505, 513 ], "type": "text", "content": "显示出更为详细的当前栈层的信息，只不过大多数都是运行时的内内地址。比如：函数", "score": 1.0 } ] }, { "bbox": [ 88, 519, 505, 532 ], "spans": [ { "bbox": [ 88, 519, 505, 532 ], "type": "text", "content": "地址，调用函数的地址，被调用函数的地址，目前的函数是由什么样的程序语言写成的、函", "score": 1.0 } ] }, { "bbox": [ 89, 538, 274, 550 ], "spans": [ { "bbox": [ 89, 538, 274, 550 ], "type": "text", "content": "数参数地址及值、局部变量的地址等等。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 572, 277, 588 ], "type": "title", "angle": 0, "index": 27, "lines": [ { "bbox": [ 114, 571, 279, 590 ], "spans": [ { "bbox": [ 114, 571, 279, 590 ], "type": "text", "content": "4.3 Linux 管道通信机制", "score": 1.0 } ] } ] }, { "bbox": [ 86, 614, 505, 663 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 110, 615, 505, 627 ], "spans": [ { "bbox": [ 110, 615, 505, 627 ], "type": "text", "content": "管道是所有UNIX 及linux都提供的一种进程间通信机制，它是进程之间的一个单向数", "score": 1.0 } ] }, { "bbox": [ 89, 634, 505, 645 ], "spans": [ { "bbox": [ 89, 634, 505, 645 ], "type": "text", "content": "据流，一个进程可向管道写入数据，另一个进程则可以从管道中读取数据，从而达到进程通", "score": 1.0 } ] }, { "bbox": [ 88, 650, 139, 664 ], "spans": [ { "bbox": [ 88, 650, 139, 664 ], "type": "text", "content": "信的目的。", "score": 1.0 } ] } ] }, { "bbox": [ 110, 673, 188, 686 ], "type": "title", "angle": 0, "index": 29, "lines": [ { "bbox": [ 111, 673, 188, 686 ], "spans": [ { "bbox": [ 111, 673, 188, 686 ], "type": "text", "content": "4.3.1 无名管道", "score": 1.0 } ] } ] }, { "bbox": [ 86, 696, 175, 709 ], "type": "title", "angle": 0, "index": 30, "lines": [ { "bbox": [ 86, 696, 174, 710 ], "spans": [ { "bbox": [ 86, 696, 174, 710 ], "type": "text", "content": "1. 无名管道概念", "score": 1.0 } ] } ] }, { "bbox": [ 108, 712, 353, 725 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 109, 712, 354, 726 ], "spans": [ { "bbox": [ 109, 712, 354, 726 ], "type": "text", "content": "无名管道通过pipe()系统调用创建，它具有如下特点：", "score": 1.0 } ] } ] }, { "bbox": [ 92, 728, 505, 756 ], "type": "list", "angle": 0, "index": 34, "blocks": [ { "bbox": [ 92, 728, 456, 740 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 94, 729, 458, 740 ], "spans": [ { "bbox": [ 94, 729, 458, 740 ], "type": "text", "content": "（1）它只能用于具有亲缘关系的进程（如父子进程或者兄弟进程）之间的通信。", "score": 1.0 } ] } ] }, { "bbox": [ 92, 743, 505, 756 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 94, 744, 506, 756 ], "spans": [ { "bbox": [ 94, 744, 506, 756 ], "type": "text", "content": "（2）管道是半双工的，具有固定的读端和写端。虽然 pipe()系统调用返回了两个文件描述", "score": 1.0 } ] } ] } ], "sub_type": "text" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 55 }, { "para_blocks": [ { "bbox": [ 112, 72, 505, 101 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 114, 72, 505, 85 ], "spans": [ { "bbox": [ 114, 72, 505, 85 ], "type": "text", "content": "符，但每个进程在使用一个文件描述符之前仍需先将另一个文件描述符关闭。如果需", "score": 1.0 } ] }, { "bbox": [ 114, 89, 381, 101 ], "spans": [ { "bbox": [ 114, 89, 381, 101 ], "type": "text", "content": "要双向的数据流，则必须通过两次 pipe()建立起两个管道。", "score": 1.0 } ] } ] }, { "bbox": [ 91, 104, 505, 132 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 95, 105, 505, 116 ], "spans": [ { "bbox": [ 95, 105, 505, 116 ], "type": "text", "content": "（3）管道可以看成是一种特殊的文件，对管道的读写与文件的读写一样使用普通的 read、", "score": 1.0 } ] }, { "bbox": [ 115, 121, 493, 132 ], "spans": [ { "bbox": [ 115, 121, 493, 132 ], "type": "text", "content": "write等函数，但它不是普通的文件，也不属于任何文件系统，而只存在于内存中。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 135, 175, 148 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 86, 134, 176, 150 ], "spans": [ { "bbox": [ 86, 134, 176, 150 ], "type": "text", "content": "2. pipe 系统调用", "score": 1.0 } ] } ] }, { "bbox": [ 92, 151, 160, 163 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 93, 150, 159, 164 ], "spans": [ { "bbox": [ 93, 150, 159, 164 ], "type": "text", "content": "（1）函数原型", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 123, 167, 222, 195 ], "blocks": [ { "bbox": [ 123, 167, 222, 195 ], "lines": [ { "bbox": [ 123, 167, 222, 195 ], "spans": [ { "bbox": [ 123, 167, 222, 195 ], "type": "text", "content": "include int pipe(int fileds[2]);" } ] } ], "index": 5, "angle": 0, "type": "code_body" } ], "index": 5, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 92, 197, 138, 210 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 93, 196, 139, 211 ], "spans": [ { "bbox": [ 93, 196, 139, 211 ], "type": "text", "content": "（2）参数", "score": 1.0 } ] } ] }, { "bbox": [ 86, 216, 502, 247 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 217, 502, 229 ], "spans": [ { "bbox": [ 109, 217, 502, 229 ], "type": "text", "content": "Filedes[2]参数：是一个输出参数，它返回两个文件描述符，其中filedes[0]指向管", "score": 1.0 } ] }, { "bbox": [ 89, 235, 273, 247 ], "spans": [ { "bbox": [ 89, 235, 273, 247 ], "type": "text", "content": "道的读端，filedes[1]指向管道的写端。", "score": 1.0 } ] } ] }, { "bbox": [ 92, 249, 138, 261 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 93, 248, 139, 263 ], "spans": [ { "bbox": [ 93, 248, 139, 263 ], "type": "text", "content": "（3）功能", "score": 1.0 } ] } ] }, { "bbox": [ 86, 268, 505, 299 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 108, 268, 506, 281 ], "spans": [ { "bbox": [ 108, 268, 506, 281 ], "type": "text", "content": "pipe在内存缓冲区中创建一个管道，并将读写该管道的一对文件描述符保存在filedes", "score": 1.0 } ] }, { "bbox": [ 88, 285, 414, 298 ], "spans": [ { "bbox": [ 88, 285, 414, 298 ], "type": "text", "content": "所指的数组中，其中filedes[0]用于读管道，filedes[1]用于写管道。", "score": 1.0 } ] } ] }, { "bbox": [ 92, 301, 149, 313 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 93, 301, 149, 314 ], "spans": [ { "bbox": [ 93, 301, 149, 314 ], "type": "text", "content": "（4）返回值", "score": 1.0 } ] } ] }, { "bbox": [ 87, 316, 327, 329 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 89, 316, 327, 329 ], "spans": [ { "bbox": [ 89, 316, 327, 329 ], "type": "text", "content": "成功返回0；失败返回-1，并在error中存入错误码。", "score": 1.0 } ] } ] }, { "bbox": [ 92, 332, 160, 344 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 93, 331, 160, 346 ], "spans": [ { "bbox": [ 93, 331, 160, 346 ], "type": "text", "content": "（5）错误代码", "score": 1.0 } ] } ] }, { "bbox": [ 87, 347, 258, 359 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 88, 348, 257, 359 ], "spans": [ { "bbox": [ 88, 348, 257, 359 ], "type": "text", "content": "EMFILE：进程使用的文件描述符过多", "score": 1.0 } ] } ] }, { "bbox": [ 123, 363, 246, 375 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 126, 363, 245, 376 ], "spans": [ { "bbox": [ 126, 363, 245, 376 ], "type": "text", "content": "ENFILE ：系统文件表已满", "score": 1.0 } ] } ] }, { "bbox": [ 123, 379, 246, 391 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 124, 378, 248, 392 ], "spans": [ { "bbox": [ 124, 378, 248, 392 ], "type": "text", "content": "EFAULT ：非法参数 filedes", "score": 1.0 } ] } ] }, { "bbox": [ 86, 394, 217, 407 ], "type": "title", "angle": 0, "index": 16, "lines": [ { "bbox": [ 86, 394, 217, 407 ], "spans": [ { "bbox": [ 86, 394, 217, 407 ], "type": "text", "content": "3. 无名管道的阻塞型读写", "score": 1.0 } ] } ] }, { "bbox": [ 86, 412, 504, 444 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 110, 412, 504, 426 ], "spans": [ { "bbox": [ 110, 412, 504, 426 ], "type": "text", "content": "管道缓冲区有4096B的长度限制，因此，采用阻塞型读写方式时，当管道已经写满时，", "score": 1.0 } ] }, { "bbox": [ 89, 432, 500, 444 ], "spans": [ { "bbox": [ 89, 432, 500, 444 ], "type": "text", "content": "写进程必须等待，直到读进程取走信息为止。同样，读空的管道时，也可能会引起进程阻塞。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 449, 481, 462 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 110, 449, 481, 462 ], "spans": [ { "bbox": [ 110, 449, 481, 462 ], "type": "text", "content": "当管道大小（管道缓冲区中待读的字节数）为 p，而用户进程请求读n个字节时：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 466, 168, 480 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 88, 468, 168, 480 ], "spans": [ { "bbox": [ 88, 468, 168, 480 ], "type": "text", "content": "若不存在写进程：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 481, 408, 526 ], "type": "list", "angle": 0, "index": 23, "blocks": [ { "bbox": [ 86, 481, 176, 494 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 88, 481, 177, 497 ], "spans": [ { "bbox": [ 88, 481, 101, 494 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.85 }, { "bbox": [ 104, 482, 122, 495 ], "type": "inline_equation", "content": "\\scriptstyle { \\mathsf { p } } = 0", "score": 0.71 }, { "bbox": [ 122, 481, 177, 497 ], "type": "text", "content": "，则返回 0；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 497, 397, 510 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 88, 497, 398, 512 ], "spans": [ { "bbox": [ 88, 497, 101, 510 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.84 }, { "bbox": [ 101, 497, 398, 512 ], "type": "text", "content": "0 } 4 0 9 6", "score": 0.82 }, { "bbox": [ 167, 714, 361, 730 ], "type": "text", "content": "则写入 n 个字节（必要时等待）并返回 n；", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 92, 731, 267, 743 ], "type": "text", "angle": 0, "index": 39, "lines": [ { "bbox": [ 92, 729, 268, 745 ], "spans": [ { "bbox": [ 92, 730, 119, 745 ], "type": "text", "content": "u≥n", "score": 1.0 }, { "bbox": [ 157, 729, 268, 745 ], "type": "text", "content": "写入n个字节，返回n。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 746, 154, 759 ], "type": "title", "angle": 0, "index": 40, "lines": [ { "bbox": [ 88, 745, 154, 761 ], "spans": [ { "bbox": [ 88, 745, 154, 761 ], "type": "text", "content": "4. 有名管道", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 56 }, { "para_blocks": [ { "bbox": [ 86, 75, 507, 214 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 110, 76, 504, 89 ], "spans": [ { "bbox": [ 110, 76, 504, 89 ], "type": "text", "content": "管道应用的一个重大限制是它没有名字，因此，只能用于具有亲缘关系的进程间通信，", "score": 1.0 } ] }, { "bbox": [ 89, 95, 505, 107 ], "spans": [ { "bbox": [ 89, 95, 505, 107 ], "type": "text", "content": "在有名管道（named pipe或FIFO）提出后，该限制得到了克服。FIFO不同于管道之处在于", "score": 1.0 } ] }, { "bbox": [ 89, 113, 497, 124 ], "spans": [ { "bbox": [ 89, 113, 497, 124 ], "type": "text", "content": "它提供一个路径名与之关联，以 FIFO的文件形式存在于文件系统中。这样，即使与 FIFO", "score": 1.0 } ] }, { "bbox": [ 89, 130, 505, 143 ], "spans": [ { "bbox": [ 89, 130, 505, 143 ], "type": "text", "content": "的创建进程不存在亲缘关系的进程，只要可以访问该路径，就能够彼此通过FIFO相互通信", "score": 1.0 } ] }, { "bbox": [ 94, 148, 506, 161 ], "spans": [ { "bbox": [ 94, 148, 506, 161 ], "type": "text", "content": "（能够访问该路径的进程以及 FIFO的创建进程之间），因此，通过 FIFO不相关的进程也能", "score": 1.0 } ] }, { "bbox": [ 89, 166, 506, 179 ], "spans": [ { "bbox": [ 89, 166, 506, 179 ], "type": "text", "content": "交换数据。值得注意的是，FIFO严格遵循先进先出（first in first out），对管道及 FIFO", "score": 1.0 } ] }, { "bbox": [ 89, 185, 505, 196 ], "spans": [ { "bbox": [ 89, 185, 505, 196 ], "type": "text", "content": "的读总是从开始处返回数据，对它们的写则把数据添加到末尾。它们不支持诸如 lseek()等", "score": 1.0 } ] }, { "bbox": [ 89, 201, 158, 215 ], "spans": [ { "bbox": [ 89, 201, 158, 215 ], "type": "text", "content": "文件定位操作。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 216, 233, 229 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 216, 233, 230 ], "spans": [ { "bbox": [ 109, 216, 233, 230 ], "type": "text", "content": "有名管道通过mkfifo 创建：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 232, 322, 277 ], "blocks": [ { "bbox": [ 108, 232, 322, 277 ], "lines": [ { "bbox": [ 108, 232, 322, 277 ], "spans": [ { "bbox": [ 108, 232, 322, 277 ], "type": "text", "content": "include \n#include \nint mkfifo(const char \\*pathname,mode_t mode)" } ] } ], "index": 3, "angle": 0, "type": "code_body" } ], "index": 3, "sub_type": "code", "guess_lang": "cpp" }, { "bbox": [ 86, 282, 504, 366 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 111, 283, 505, 295 ], "spans": [ { "bbox": [ 111, 283, 505, 295 ], "type": "text", "content": "该函数的第一个参数是一个普通的路径名，也就是创建后 FIFO的名字。第二个参数与", "score": 1.0 } ] }, { "bbox": [ 89, 301, 495, 312 ], "spans": [ { "bbox": [ 89, 301, 495, 312 ], "type": "text", "content": "打开普通文件的open()函数中的mode 参数相同。 有名管道创建成功，mkfifo()返回 0；", "score": 1.0 } ] }, { "bbox": [ 90, 319, 494, 330 ], "spans": [ { "bbox": [ 90, 319, 494, 330 ], "type": "text", "content": "否则返回-1。如果mkfifo的第一个参数是一个已经存在的路径名时，错误代码中会返回", "score": 1.0 } ] }, { "bbox": [ 89, 337, 499, 349 ], "spans": [ { "bbox": [ 89, 337, 499, 349 ], "type": "text", "content": "EEXIST错误，所以一般典型的调用代码首先会检查是否返回该错误，如果确实返回该错误，", "score": 1.0 } ] }, { "bbox": [ 89, 354, 278, 367 ], "spans": [ { "bbox": [ 89, 354, 278, 367 ], "type": "text", "content": "那么只要调用打开FIFO的函数就可以了。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 372, 504, 402 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 371, 505, 385 ], "spans": [ { "bbox": [ 110, 371, 505, 385 ], "type": "text", "content": "与普通文件类似，有名管道在使用之前必须先进行open操作，具体类似于文件的打开", "score": 1.0 } ] }, { "bbox": [ 88, 389, 117, 405 ], "spans": [ { "bbox": [ 88, 389, 117, 405 ], "type": "text", "content": "方式：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 405, 289, 465 ], "blocks": [ { "bbox": [ 108, 405, 289, 465 ], "lines": [ { "bbox": [ 108, 405, 289, 465 ], "spans": [ { "bbox": [ 108, 405, 289, 465 ], "type": "text", "content": "include \n#include \n#include \nint open(const char \\*pathname,int flags);" } ] } ], "index": 6, "angle": 0, "type": "code_body" } ], "index": 6, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 86, 470, 505, 591 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 471, 506, 483 ], "spans": [ { "bbox": [ 109, 471, 506, 483 ], "type": "text", "content": "对有名管道的open操作必须遵循下列规则：（1）如果当前打开操作是为读而打开 FIFO", "score": 1.0 } ] }, { "bbox": [ 88, 489, 502, 501 ], "spans": [ { "bbox": [ 88, 489, 502, 501 ], "type": "text", "content": "时，若已经有相应进程为写而打开该FIFO，则当前打开操作将成功返回；否则，可能阻塞", "score": 1.0 } ] }, { "bbox": [ 89, 507, 505, 519 ], "spans": [ { "bbox": [ 89, 507, 505, 519 ], "type": "text", "content": "直到有相应进程为写而打开该 FIFO（当前打开操作设置了阻塞标志）；或者，成功返回（当", "score": 1.0 } ] }, { "bbox": [ 89, 525, 505, 538 ], "spans": [ { "bbox": [ 89, 525, 505, 538 ], "type": "text", "content": "前打开操作没有设置阻塞标志）。（2）如果当前打开操作是为写而打开FIFO时，如果已经", "score": 1.0 } ] }, { "bbox": [ 89, 544, 502, 555 ], "spans": [ { "bbox": [ 89, 544, 502, 555 ], "type": "text", "content": "有相应进程为读而打开该FIFO，则当前打开操作将成功返回；否则，可能阻塞直到有相应", "score": 1.0 } ] }, { "bbox": [ 88, 560, 502, 573 ], "spans": [ { "bbox": [ 88, 560, 502, 573 ], "type": "text", "content": "进程为读而打开该FIFO（当前打开操作设置了阻塞标志）；或者，返回ENXIO 错误（当前", "score": 1.0 } ] }, { "bbox": [ 89, 580, 231, 591 ], "spans": [ { "bbox": [ 89, 580, 231, 591 ], "type": "text", "content": "打开操作没有设置阻塞标志）。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 596, 505, 627 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 110, 597, 506, 610 ], "spans": [ { "bbox": [ 110, 597, 506, 610 ], "type": "text", "content": "一旦打开操作成功，便可通过返回的文件描述符，利用 read、write系统调用对管道进", "score": 1.0 } ] }, { "bbox": [ 89, 615, 368, 627 ], "spans": [ { "bbox": [ 89, 615, 368, 627 ], "type": "text", "content": "行读写操作，读写完成应使用 close系统调用关闭有名管道。", "score": 1.0 } ] } ] }, { "bbox": [ 114, 649, 305, 665 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 648, 307, 666 ], "spans": [ { "bbox": [ 114, 648, 307, 666 ], "type": "text", "content": "4.4 Linux 消息队列通信机制", "score": 1.0 } ] } ] }, { "bbox": [ 86, 691, 505, 759 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 692, 505, 704 ], "spans": [ { "bbox": [ 109, 692, 505, 704 ], "type": "text", "content": "Linux系统中，若干个进程可以共享一个消息队列，系统允许其中的一个或多个进程向", "score": 1.0 } ] }, { "bbox": [ 89, 709, 505, 722 ], "spans": [ { "bbox": [ 89, 709, 505, 722 ], "type": "text", "content": "消息队列写入消息，同时也允许一个或多个进程从消息队列中读取消息，从而完成进程之间", "score": 1.0 } ] }, { "bbox": [ 89, 728, 505, 740 ], "spans": [ { "bbox": [ 89, 728, 505, 740 ], "type": "text", "content": "的信息交换，这种通信机制被称作消息队列通信机制。消息队列通信机制是客户/服务器模", "score": 1.0 } ] }, { "bbox": [ 89, 745, 504, 757 ], "spans": [ { "bbox": [ 89, 745, 504, 757 ], "type": "text", "content": "型中常用的进程通信方式：客户向服务器发送请求信息，服务器读取消息并执行相应的请求。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 57 }, { "para_blocks": [ { "bbox": [ 86, 76, 241, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 89, 77, 242, 89 ], "spans": [ { "bbox": [ 89, 77, 242, 89 ], "type": "text", "content": "消息可以是命令，也可以是数据。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 94, 166, 107 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 94, 166, 107 ], "spans": [ { "bbox": [ 109, 94, 166, 107 ], "type": "text", "content": "1.数据结构", "score": 1.0 } ] } ] }, { "bbox": [ 92, 112, 241, 125 ], "type": "title", "angle": 0, "index": 3, "lines": [ { "bbox": [ 94, 110, 242, 127 ], "spans": [ { "bbox": [ 94, 110, 242, 127 ], "type": "text", "content": "（1）消息缓冲区 struct msgbuf", "score": 1.0 } ] } ] }, { "bbox": [ 86, 130, 505, 179 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 131, 506, 142 ], "spans": [ { "bbox": [ 110, 131, 506, 142 ], "type": "text", "content": "消息缓冲区是用来存放消息内容的结构体，而且这个结构体的第一个成员必须是一个大", "score": 1.0 } ] }, { "bbox": [ 89, 148, 500, 160 ], "spans": [ { "bbox": [ 89, 148, 500, 160 ], "type": "text", "content": "于0 的长整数，表示对应消息的类型；不过，系统对结构体中其余成员的类型不做任何限制。", "score": 1.0 } ] }, { "bbox": [ 88, 166, 323, 179 ], "spans": [ { "bbox": [ 88, 166, 323, 179 ], "type": "text", "content": "include/linux/msg.h 中给出的消息缓冲格式如下：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 184, 432, 250 ], "blocks": [ { "bbox": [ 108, 184, 432, 250 ], "lines": [ { "bbox": [ 108, 184, 432, 250 ], "spans": [ { "bbox": [ 108, 184, 432, 250 ], "type": "text", "content": "struct msgbuf{ /*消息定义的参照格式*/\n long mtype; /*消息类型（大于0的长整数）\n char mtext[1]; /*消息正文*/\n};" } ] } ], "index": 5, "angle": 0, "type": "code_body" } ], "index": 5, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 86, 255, 505, 305 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 257, 505, 268 ], "spans": [ { "bbox": [ 110, 257, 505, 268 ], "type": "text", "content": "应用程序员可以重新定义消息缓冲区结构体，其中，成员(mtext)不仅能定义为长度为", "score": 1.0 } ] }, { "bbox": [ 88, 274, 505, 287 ], "spans": [ { "bbox": [ 88, 274, 505, 287 ], "type": "text", "content": "1 的字符数组，也可以定义成长度大于 1的字符数组，或定义成其他的数据类型，Linux也", "score": 1.0 } ] }, { "bbox": [ 89, 293, 334, 304 ], "spans": [ { "bbox": [ 89, 293, 334, 304 ], "type": "text", "content": "允许消息正文的长度为 0，即结构体中没有mtext域。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 310, 505, 341 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 111, 311, 505, 322 ], "spans": [ { "bbox": [ 111, 311, 505, 322 ], "type": "text", "content": "虽然，Linux没限定 mtext的类型，但却限定了消息的长度，一个消息的最大长度由宏", "score": 1.0 } ] }, { "bbox": [ 88, 328, 377, 340 ], "spans": [ { "bbox": [ 88, 328, 377, 340 ], "type": "text", "content": "MSGMAX决定，根据版本的不同，其取值可能为8192或其他值。", "score": 1.0 } ] } ] }, { "bbox": [ 92, 346, 214, 359 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 93, 343, 216, 362 ], "spans": [ { "bbox": [ 93, 343, 216, 362 ], "type": "text", "content": "（2）消息结构 struct msg", "score": 1.0 } ] } ] }, { "bbox": [ 87, 364, 505, 395 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 364, 506, 376 ], "spans": [ { "bbox": [ 109, 364, 506, 376 ], "type": "text", "content": "消息队列中的每个消息节点中不仅包含了消息内容，还包含了一些其他信息，消息节点", "score": 1.0 } ] }, { "bbox": [ 89, 382, 418, 396 ], "spans": [ { "bbox": [ 89, 382, 418, 396 ], "type": "text", "content": "由消息结构来描述。include/linux/msg.h 中给出的消息结构格式如下：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 400, 474, 520 ], "blocks": [ { "bbox": [ 108, 400, 474, 520 ], "lines": [ { "bbox": [ 108, 400, 474, 520 ], "spans": [ { "bbox": [ 108, 400, 474, 520 ], "type": "text", "content": "struct msg {\n struct msg *msg_next; /*消息队列链接指针，指向队列中的下一条消息 */\n long msg_type; /*消息类型，同 struct msgbuf 中的 mtype*/\n char *msgSpot; /*消息正文的地址，指向 msgbuf 的消息正文 */\n time_t msg_stime; /*消息发送的时间 */\n short msg-ts; /*消息正文的大小 */\n};" } ] } ], "index": 10, "angle": 0, "type": "code_body" } ], "index": 10, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 92, 526, 281, 539 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 93, 523, 282, 541 ], "spans": [ { "bbox": [ 93, 523, 282, 541 ], "type": "text", "content": "（3）IPC 对象访问权限 struct ipc_perm", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 544, 468, 717 ], "blocks": [ { "bbox": [ 108, 544, 468, 717 ], "lines": [ { "bbox": [ 108, 544, 468, 717 ], "spans": [ { "bbox": [ 108, 544, 468, 717 ], "type": "text", "content": "struct ipcperm{ \nkey_t key; /* IPC对象键值*/ \nushort uid; /* owner euid and egid */ \nushort gid; \nushort cuid; /* creator euid and egid */ \nushort cgid; \nushort mode; /* 访问权限 */ \nushort seq; /* slot usage sequence number，即IPC对象使用频率信息*/}; \n其中：" } ] } ], "index": 12, "angle": 0, "type": "code_body" } ], "index": 12, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 86, 724, 505, 755 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 110, 724, 505, 736 ], "spans": [ { "bbox": [ 110, 724, 505, 736 ], "type": "text", "content": "Key 是IPC对象（例如消息队列，共享存储器等）的键值，每个 IPC对象都关联着一个", "score": 1.0 } ] }, { "bbox": [ 89, 742, 505, 754 ], "spans": [ { "bbox": [ 89, 742, 505, 754 ], "type": "text", "content": "唯一的长整型的键值，不同的进程通过相同的键值可访问到同一个IPC对象。用户进程在创", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 58 }, { "para_blocks": [ { "bbox": [ 86, 75, 507, 198 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 89, 77, 504, 88 ], "spans": [ { "bbox": [ 89, 77, 504, 88 ], "type": "text", "content": "建IPC对象时可以指定 key为某个大于0的整数，此时，需要用户自己保证该 key值不与系", "score": 1.0 } ] }, { "bbox": [ 88, 94, 501, 107 ], "spans": [ { "bbox": [ 88, 94, 501, 107 ], "type": "text", "content": "统中存在的其他IPC键值相冲突。更常用的方式是通过函数调用 ftok（pathname，proj_jd）", "score": 1.0 } ] }, { "bbox": [ 89, 113, 504, 125 ], "spans": [ { "bbox": [ 89, 113, 504, 125 ], "type": "text", "content": "请求系统为用户进程生成一个键值，其中的pathname 是一个实际存在的文件的路径名，而", "score": 1.0 } ] }, { "bbox": [ 89, 131, 502, 143 ], "spans": [ { "bbox": [ 89, 131, 502, 143 ], "type": "text", "content": "且用户进程具有对该文件的访问权限，proj_jd是一个整数，但 ftok只会用到其低 8位的", "score": 1.0 } ] }, { "bbox": [ 89, 148, 500, 161 ], "spans": [ { "bbox": [ 89, 148, 500, 161 ], "type": "text", "content": "值（该值不能为0），只要路径名访问到的是同一个文件，而且 proj_jd的低8 位的值相同，", "score": 1.0 } ] }, { "bbox": [ 89, 166, 505, 179 ], "spans": [ { "bbox": [ 89, 166, 505, 179 ], "type": "text", "content": "则ftok()调用便将产生相同的键值；如果使用不同的文件路径名和 proj_jd，虽然系统不能", "score": 1.0 } ] }, { "bbox": [ 89, 185, 252, 196 ], "spans": [ { "bbox": [ 89, 185, 252, 196 ], "type": "text", "content": "保证、但通常生成的键值是不同的。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 201, 506, 234 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 203, 505, 215 ], "spans": [ { "bbox": [ 109, 203, 505, 215 ], "type": "text", "content": "Mode 中给出了该IPC对象的访问权限，由9 个二进制位表示所有者、同组用户、其他", "score": 1.0 } ] }, { "bbox": [ 89, 221, 304, 232 ], "spans": [ { "bbox": [ 89, 221, 304, 232 ], "type": "text", "content": "组用户的访问权限。它可以是下列权限的组合：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 192, 237, 333, 359 ], "blocks": [ { "bbox": [ 192, 237, 333, 359 ], "lines": [ { "bbox": [ 192, 237, 333, 359 ], "spans": [ { "bbox": [ 192, 237, 333, 359 ], "type": "table", "html": "
访问权限八进制整数
拥有者可读0400
拥有者可写0200
同组用户可读0040
同组用户可写0020
其他用户可读0004
其他用户可写0002
", "image_path": "627d7f2a996a73ea8988306bc1d29e9dd739dabc725aab29c2287e9412d65e10.jpg" } ] } ], "index": 3, "angle": 0, "type": "table_body" } ], "index": 3 }, { "bbox": [ 86, 364, 501, 395 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 364, 499, 377 ], "spans": [ { "bbox": [ 110, 364, 499, 377 ], "type": "text", "content": "由于系统规定任何 IPC结构都不存在可执行权限，因此一个IPC对象的权限最大值为", "score": 1.0 } ] }, { "bbox": [ 88, 381, 168, 395 ], "spans": [ { "bbox": [ 88, 381, 168, 395 ], "type": "text", "content": "0666（八进制）。", "score": 1.0 } ] } ] }, { "bbox": [ 92, 400, 273, 413 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 93, 397, 273, 415 ], "spans": [ { "bbox": [ 93, 397, 273, 415 ], "type": "text", "content": "（4）消息队列结构体 struct msqid_ds", "score": 1.0 } ] } ] }, { "bbox": [ 86, 417, 506, 449 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 417, 506, 431 ], "spans": [ { "bbox": [ 110, 417, 506, 431 ], "type": "text", "content": "系统中每个消息队列由一个 struct msqid_ds 类型的变量来描述，struct msqid_ds 的", "score": 1.0 } ] }, { "bbox": [ 88, 435, 137, 449 ], "spans": [ { "bbox": [ 88, 435, 137, 449 ], "type": "text", "content": "格式如下：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 454, 432, 700 ], "blocks": [ { "bbox": [ 108, 454, 432, 700 ], "lines": [ { "bbox": [ 108, 454, 432, 700 ], "spans": [ { "bbox": [ 108, 454, 432, 700 ], "type": "text", "content": "struct msqid_ds {\n struct ipcperm msg_perm; /* 消息队列访问权限*/\n struct msg *msg_first; /* 队列上第一条消息，即链表头*/\n struct msg *msg_last; /* 队列中的最后一条消息，即链表尾*/\n time_t msg_stime; /* 发送给队列的最后一条消息的时间 */\n time_t msg_rtime; /* 从消息队列接收到最后一条消息的时间 */\n time_t msg_ctime; /* 最后修改队列的时间*/\n}\n... \nushort msg_cbytes; /*队列上所有消息总的字节数 */\nushort msg_qnum; /*当前队列上消息的个数 */\nushort msg_qbytes; /* 队列允许的最大的字节数 */\nushort msg_lspid; /* 发送最后一条消息的进程的 pid */\nushort msg_lrpid; /* 接收最后一条消息的进程的 pid */\n};" } ] } ], "index": 7, "angle": 0, "type": "code_body" } ], "index": 7, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 107, 705, 504, 719 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 705, 505, 719 ], "spans": [ { "bbox": [ 109, 705, 505, 719 ], "type": "text", "content": "Linux还通过宏MSGMNB限定了一个消息队列的最大长度（队列中所有消息总的字节数）。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 724, 239, 737 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 110, 724, 238, 736 ], "spans": [ { "bbox": [ 110, 724, 238, 736 ], "type": "text", "content": "2.消息队列相关的系统调用", "score": 1.0 } ] } ] }, { "bbox": [ 107, 741, 428, 755 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 741, 429, 755 ], "spans": [ { "bbox": [ 109, 741, 429, 755 ], "type": "text", "content": "Linux提供了一组消息队列相关的系统调用来方便用户进行消息通信。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 59 }, { "para_blocks": [ { "bbox": [ 92, 75, 193, 89 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 93, 75, 193, 91 ], "spans": [ { "bbox": [ 93, 75, 193, 91 ], "type": "text", "content": "（1）msgget 系统调用", "score": 1.0 } ] } ] }, { "bbox": [ 108, 94, 167, 106 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 94, 168, 107 ], "spans": [ { "bbox": [ 109, 94, 121, 106 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.83 }, { "bbox": [ 122, 94, 168, 107 ], "type": "text", "content": "函数原型：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 112, 289, 179 ], "blocks": [ { "bbox": [ 108, 112, 289, 179 ], "lines": [ { "bbox": [ 108, 112, 289, 179 ], "spans": [ { "bbox": [ 108, 112, 289, 179 ], "type": "text", "content": "include \n#include \n#include \nint msgget(key_t key, int msgflg);" } ] } ], "index": 3, "angle": 0, "type": "code_body" } ], "index": 3, 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"spans": [ { "bbox": [ 108, 238, 506, 250 ], "type": "text", "content": "msgflg 对消息队列的访问权限和控制命令的组合。其中访问权限见“IPC 对象访问权", "score": 1.0 } ] }, { "bbox": [ 88, 256, 506, 269 ], "spans": [ { "bbox": [ 88, 256, 506, 269 ], "type": "text", "content": "限 struct ipc_perm”部分的说明。而控制命令 IPC_CREAT 表示，如果 key 对应的消息队列", "score": 1.0 } ] }, { "bbox": [ 89, 275, 504, 286 ], "spans": [ { "bbox": [ 89, 275, 504, 286 ], "type": "text", "content": "不存在，则创建它；而 IPC_EXCL必须与IPC_CREATT一起使用，它表示：如果 key对应的消", "score": 1.0 } ] }, { "bbox": [ 89, 292, 327, 305 ], "spans": [ { "bbox": [ 89, 292, 327, 305 ], "type": "text", "content": "息队列不存在，则创建一个新的队列，否则返回-1。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 310, 506, 395 ], "type": "list", "angle": 0, "index": 9, "blocks": [ { "bbox": [ 86, 310, 500, 359 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 309, 499, 323 ], "spans": [ { "bbox": [ 109, 310, 121, 322 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.86 }, { "bbox": [ 122, 309, 499, 323 ], "type": "text", "content": "功能： 如果IPC_CREAT 单独使用，semget()为一个新创建的消息队列返回标识数，", "score": 1.0 } ] }, { "bbox": [ 89, 329, 498, 340 ], "spans": [ { "bbox": [ 89, 329, 498, 340 ], "type": "text", "content": "或者返回具有相同键值的已存在消息队列标识数。如果 IPC_EXCL与 IPC_CREAT 一起使用，", "score": 1.0 } ] }, { "bbox": [ 88, 346, 421, 359 ], "spans": [ { "bbox": [ 88, 346, 421, 359 ], "type": "text", "content": "要么创建一个新的队列并返回它的标识数，如果队列已存在，则返回-1。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 364, 506, 395 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 364, 506, 377 ], "spans": [ { "bbox": [ 109, 364, 121, 376 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.81 }, { "bbox": [ 122, 364, 506, 377 ], "type": "text", "content": "返回值：成功，返回消息队列的标识数；出错，返回-1，同时将错误代码存放在 error", "score": 1.0 } ] }, { "bbox": [ 89, 383, 425, 394 ], "spans": [ { "bbox": [ 89, 383, 425, 394 ], "type": "text", "content": "中。对于新创建的消息队列，其msqid_ds结构成员变量的初值设置如下：", "score": 1.0 } ] } ] } ], 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"错误代码：EACCES：指定的消息队列已存在，但调用进程没有权限访问它", "score": 1.0 } ] } ] }, { "bbox": [ 86, 544, 505, 573 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 544, 506, 557 ], "spans": [ { "bbox": [ 109, 544, 506, 557 ], "type": "text", "content": "EEXIST：key 指定的消息队列已存在，而 msgflg 中同时指定 IPC_CREAT 和 IPC_EXCL 标", "score": 1.0 } ] }, { "bbox": [ 86, 560, 103, 576 ], "spans": [ { "bbox": [ 86, 560, 103, 576 ], "type": "text", "content": "志", "score": 1.0 } ] } ] }, { "bbox": [ 107, 579, 460, 592 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 108, 579, 460, 593 ], "spans": [ { "bbox": [ 108, 579, 460, 593 ], "type": "text", "content": "ENOENT：key 指定的消息队列不存在同时 msgflg 中没有指定 IPC_CREAT 标志", "score": 1.0 } ] } ] }, { "bbox": [ 107, 597, 301, 610 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 597, 300, 611 ], "spans": [ { "bbox": [ 109, 597, 300, 611 ], "type": "text", "content": "ENOMEM：需要建立消息队列，但内存不足", "score": 1.0 } ] } ] }, { "bbox": [ 107, 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"content": "include \n#include \n#include \nint mgsnd(int msqid, struct msgbuf \\*msgp,size_t msgsz,int msgflg);" } ] } ], "index": 23, "angle": 0, "type": "code_body" } ], "index": 23, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 108, 741, 146, 754 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 109, 740, 149, 756 ], "spans": [ { "bbox": [ 109, 741, 121, 754 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.84 }, { "bbox": [ 122, 740, 149, 756 ], "type": "text", "content": "参数:", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 60 }, { "para_blocks": [ { "bbox": [ 107, 76, 238, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 108, 76, 238, 89 ], "spans": [ { "bbox": [ 108, 76, 238, 89 ], "type": "text", "content": "msqid 消息队列的标识数", "score": 1.0 } ] } ] }, { "bbox": [ 107, 94, 332, 107 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 95, 332, 109 ], "spans": [ { "bbox": [ 108, 95, 134, 109 ], "type": "text", "content": "msgp", "score": 1.0 }, { "bbox": [ 151, 95, 332, 107 ], "type": "text", "content": "存放欲发送消息内容的消息缓冲区指针", "score": 1.0 } ] } ] }, { "bbox": [ 107, 112, 322, 126 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 112, 321, 126 ], "spans": [ { "bbox": [ 108, 115, 139, 126 ], "type": "text", "content": "msgsz", "score": 1.0 }, { "bbox": [ 151, 112, 321, 126 ], "type": "text", "content": "消息正文(而非整个消息结构)的长度", "score": 1.0 } ] } ] }, { "bbox": [ 107, 130, 408, 142 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 107, 130, 408, 145 ], "spans": [ { "bbox": [ 107, 130, 149, 145 ], "type": "text", "content": "msgflg：", "score": 1.0 }, { "bbox": [ 172, 131, 180, 142 ], "type": "text", "content": "0", "score": 1.0 }, { "bbox": [ 252, 130, 408, 144 ], "type": "text", "content": "—消息队列满时，msgsnd 将会阻塞", "score": 1.0 } ] } ] }, { "bbox": [ 171, 148, 413, 161 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 173, 148, 413, 161 ], "spans": [ { "bbox": [ 173, 148, 413, 161 ], "type": "text", "content": "IPC_NOWAIT ——消息队列满时，msgsnd 立即返回-1", "score": 1.0 } ] } ] }, { "bbox": [ 86, 166, 505, 196 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 172, 166, 505, 179 ], "spans": [ { "bbox": [ 172, 166, 505, 179 ], "type": "text", "content": "MSG_NOERROR——消息正文长度超过 msgsz字节时，不报错，而是直接截", "score": 1.0 } ] }, { "bbox": [ 89, 184, 342, 196 ], "spans": [ { "bbox": [ 89, 184, 342, 196 ], "type": "text", "content": "去其中多余的部分，并只将前面的 msgsz字节发送出去", "score": 1.0 } ] } ] }, { "bbox": [ 86, 201, 505, 269 ], "type": "list", "angle": 0, "index": 10, "blocks": [ { "bbox": [ 86, 201, 505, 232 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 200, 505, 216 ], "spans": [ { "bbox": [ 109, 201, 121, 214 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.86 }, { "bbox": [ 122, 200, 157, 216 ], "type": "text", "content": "功能：", "score": 1.0 }, { "bbox": [ 166, 202, 505, 216 ], "type": "text", "content": "在标识数为 msqid 的消息队列中添加一个消息，即向标识数为 msqid 的消", "score": 1.0 } ] }, { "bbox": [ 89, 220, 190, 232 ], "spans": [ { "bbox": [ 89, 220, 190, 232 ], "type": "text", "content": "息队列发送一个消息。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 238, 471, 251 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 238, 471, 251 ], "spans": [ { "bbox": [ 109, 238, 121, 250 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.84 }, { "bbox": [ 122, 238, 471, 251 ], "type": "text", "content": "返回值： 消息发送成功，返回0；否则返回-1，同时error中存有错误代码", "score": 1.0 } ] } ] }, { "bbox": [ 107, 255, 449, 269 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 255, 451, 270 ], "spans": [ { "bbox": [ 109, 256, 121, 268 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.86 }, { "bbox": [ 121, 255, 451, 270 ], "type": "text", "content": "错误代码：EAGAIN ——参数 msgflg 设为 IPC_NOWAIT，而消息队列已满", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 274, 263, 286 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 109, 275, 264, 287 ], "spans": [ { "bbox": [ 109, 275, 264, 287 ], "type": "text", "content": "EACCESS——无权限写入消息队列", "score": 1.0 } ] } ] }, { "bbox": [ 107, 291, 311, 305 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 108, 290, 311, 306 ], "spans": [ { "bbox": [ 108, 290, 311, 306 ], "type": "text", "content": "EFAULT ——参数 msgp 指向的地址无法访问", "score": 1.0 } ] } ] }, { "bbox": [ 107, 310, 337, 322 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 108, 309, 337, 323 ], "spans": [ { "bbox": [ 108, 310, 140, 322 ], "type": "text", "content": "EIDRM", "score": 1.0 }, { "bbox": [ 164, 309, 337, 323 ], "type": "text", "content": "标识符为 msqid的消息队列已被删除", "score": 1.0 } ] } ] }, { "bbox": [ 107, 327, 368, 340 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 328, 368, 341 ], "spans": [ { "bbox": [ 109, 328, 140, 341 ], "type": "text", "content": "EINTR", "score": 1.0 }, { "bbox": [ 148, 334, 160, 337 ], "type": "text", "content": "——", "score": 1.0 }, { "bbox": [ 166, 328, 368, 341 ], "type": "text", "content": "队列已满而处于阻塞的情况下，被信号唤醒", "score": 1.0 } ] } ] }, { "bbox": [ 87, 345, 505, 375 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 108, 345, 505, 359 ], "spans": [ { "bbox": [ 108, 345, 505, 359 ], "type": "text", "content": "EINVAL ——无效的参数msqid、或消息类型 type小于等于 0、或 msgsz为负数或超过", "score": 1.0 } ] }, { "bbox": [ 89, 364, 178, 376 ], "spans": [ { "bbox": [ 89, 364, 178, 376 ], "type": "text", "content": "系统限制值 MSGMAX", "score": 1.0 } ] } ] }, { "bbox": [ 107, 381, 374, 395 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 109, 381, 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"text", "content": "1. 共享内存的系统调用", "score": 1.0 } ] } ] }, { "bbox": [ 86, 200, 508, 267 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 200, 505, 212 ], "spans": [ { "bbox": [ 110, 200, 505, 212 ], "type": "text", "content": "任何Linux进程创建时，都有很大的虚拟地址空间，这块虚拟地址空间只有一部分放着", "score": 1.0 } ] }, { "bbox": [ 89, 218, 499, 229 ], "spans": [ { "bbox": [ 89, 218, 499, 229 ], "type": "text", "content": "代码、数据、堆和堆栈，剩余的那些部分在初始化时是空闲的。一块共享内存一旦被连接", "score": 1.0 } ] }, { "bbox": [ 94, 236, 505, 248 ], "spans": [ { "bbox": [ 94, 236, 505, 248 ], "type": "text", "content": "（attach），即会被映射入空闲的虚拟地址空间。随后，进程即可像对待普通的内存区域那", "score": 1.0 } ] }, { "bbox": [ 89, 254, 389, 265 ], "spans": [ { "bbox": [ 89, 254, 389, 265 ], "type": "text", "content": "样读、写共享内存。共享内存一共有四个系统调用，它们分别是：", "score": 1.0 } ] } ] }, { "bbox": [ 111, 270, 471, 341 ], "type": "list", "angle": 0, "index": 8, "blocks": [ { "bbox": [ 111, 270, 275, 282 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 132, 270, 276, 283 ], "spans": [ { "bbox": [ 132, 270, 276, 283 ], "type": "text", "content": "shmget（）创建一块共享内存。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 289, 456, 301 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 132, 290, 456, 302 ], "spans": [ { "bbox": [ 132, 290, 456, 302 ], "type": "text", "content": "shmat（）将一块已存在共享内存映射（map）到一个进程的地址空间。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 309, 461, 322 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 131, 309, 462, 323 ], "spans": [ { "bbox": [ 131, 309, 462, 323 ], "type": "text", "content": "shmdt（）取消一个进程的地址空间中一块共享内存块的映射（unmap）。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 328, 471, 341 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 132, 329, 472, 341 ], "spans": [ { "bbox": [ 132, 329, 472, 341 ], "type": "text", "content": "shmctl（）是管理共享内存的函数，用于执行对共享内存的各种控制命令。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 110, 348, 281, 361 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 110, 346, 282, 364 ], "spans": [ { "bbox": [ 110, 346, 282, 364 ], "type": "text", "content": "（1） shmget ()：分配一块共享内存", "score": 1.0 } ] } ] }, { "bbox": [ 111, 367, 181, 380 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 133, 367, 182, 381 ], "spans": [ { "bbox": [ 133, 367, 182, 381 ], "type": "text", "content": "函数声明：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 130, 387, 296, 439 ], "blocks": [ { "bbox": [ 130, 387, 296, 439 ], "lines": [ { "bbox": [ 130, 387, 296, 439 ], "spans": [ { "bbox": [ 130, 387, 296, 439 ], "type": "text", "content": "include \n#include \nint shmget(key_t,int size,int shmflg);" } ] } ], "index": 11, "angle": 0, "type": "code_body" } ], "index": 11, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 111, 445, 180, 458 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 132, 444, 182, 460 ], "spans": [ { "bbox": [ 132, 444, 182, 460 ], "type": "text", "content": "输入参数：", "score": 1.0 } ] } ] }, { "bbox": [ 130, 465, 361, 478 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 132, 465, 342, 478 ], "spans": [ { "bbox": [ 132, 465, 342, 478 ], "type": "text", "content": "key:标识共享内存的键值，在调用前应赋初值", "score": 1.0 } ] } ] }, { "bbox": [ 130, 484, 361, 497 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 132, 485, 361, 497 ], "spans": [ { "bbox": [ 132, 485, 361, 497 ], "type": "text", "content": "Size:所需的共享内存的最小尺寸（以字节为单位）", "score": 1.0 } ] } ] }, { "bbox": [ 131, 503, 293, 517 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 133, 503, 293, 517 ], "spans": [ { "bbox": [ 133, 503, 293, 517 ], "type": "text", "content": "shmflg:将分配的共享内存属性标志", "score": 1.0 } ] } ] }, { "bbox": [ 111, 523, 170, 535 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 132, 523, 171, 538 ], "spans": [ { "bbox": [ 132, 523, 171, 538 ], "type": "text", "content": "返回值：", "score": 1.0 } ] } ] }, { "bbox": [ 130, 542, 480, 555 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 133, 543, 481, 556 ], "spans": [ { "bbox": [ 133, 543, 481, 556 ], "type": "text", "content": "若成功，则返回共享内存的标识符；否则返回-1，错误原因存在于errno中。", "score": 1.0 } ] } ] }, { "bbox": [ 130, 562, 419, 575 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 131, 560, 421, 577 ], "spans": [ { "bbox": [ 131, 560, 421, 577 ], "type": "text", "content": "errno=EINVAL：参数 size 小于 SHMMIN 或者大于 SHMMAX。", "score": 1.0 } ] } ] }, { "bbox": [ 130, 581, 377, 594 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 133, 582, 377, 595 ], "spans": [ { "bbox": [ 133, 582, 377, 595 ], "type": "text", "content": "EEXIST：欲建立 key所指的共享内存，但已经存在。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 601, 340, 613 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 133, 602, 341, 614 ], "spans": [ { "bbox": [ 133, 602, 341, 614 ], "type": "text", "content": "EIDRM：参数 key所指的共享内存已经删除。", "score": 1.0 } ] } ] }, { "bbox": [ 130, 621, 448, 634 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 132, 620, 449, 635 ], "spans": [ { "bbox": [ 132, 620, 449, 635 ], "type": "text", "content": "ENOSPC：已经超过系统允许建立的共享内存的最大值（SHMALL）。", "score": 1.0 } ] } ] }, { "bbox": [ 130, 640, 498, 654 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 132, 640, 499, 655 ], "spans": [ { "bbox": [ 132, 640, 499, 655 ], "type": "text", "content": "ENOENT：参数 key 所指的共享内存不存在，参数 shmflg 也未设 IPC_CREAT 位。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 660, 238, 672 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 132, 660, 239, 673 ], "spans": [ { "bbox": [ 132, 660, 239, 673 ], "type": "text", "content": "EACCESS：没有权限。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 679, 259, 692 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 133, 679, 260, 692 ], "spans": [ { "bbox": [ 133, 679, 260, 692 ], "type": "text", "content": "ENOMEM：核心内存不足。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 698, 159, 711 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 116, 698, 162, 713 ], "spans": [ { "bbox": [ 116, 703, 119, 707 ], "type": "text", "content": "", "score": 0.0 }, { "bbox": [ 132, 698, 162, 713 ], "type": "text", "content": "说明：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 719, 506, 751 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 110, 719, 506, 733 ], "spans": [ { "bbox": [ 110, 719, 506, 733 ], "type": "text", "content": "参数key的取值可以是一块已经存在的共享内存的键值、0、或IPC_PRIVATE。如果key", "score": 1.0 } ] }, { "bbox": [ 89, 737, 504, 751 ], "spans": [ { "bbox": [ 89, 737, 504, 751 ], "type": "text", "content": "的取值为IPC_PRIVATE，则函数shmget()将创建一块新的共享内存；如果 key 的取值为 0，", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 63 }, { "para_blocks": [ { "bbox": [ 86, 76, 507, 126 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 89, 77, 505, 88 ], "spans": [ { "bbox": [ 89, 77, 505, 88 ], "type": "text", "content": "而参数shmflg中设置了IPC_CREATE这标志，则同样将创建一块新的共享内存。在 IPC的通", "score": 1.0 } ] }, { "bbox": [ 89, 95, 506, 106 ], "spans": [ { "bbox": [ 89, 95, 506, 106 ], "type": "text", "content": "信模式下，不管是使用消息队列或者是共享内存，甚至是信号量，每个 IPC的对象都有唯一", "score": 1.0 } ] }, { "bbox": [ 88, 111, 246, 125 ], "spans": [ { "bbox": [ 88, 111, 246, 125 ], "type": "text", "content": "的名字，它被称做“键”（key）。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 130, 458, 144 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 130, 458, 142 ], "spans": [ { "bbox": [ 109, 130, 458, 142 ], "type": "text", "content": "参数size是要建立的共享内存的长度。所有的内存分配都是以页为单位的。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 148, 506, 179 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 148, 505, 161 ], "spans": [ { "bbox": [ 110, 148, 505, 161 ], "type": "text", "content": "参数shmflg主要和一些标志有关。其中有效的标志包括 IPC_CREAT和 IPC_EXCL，它们", "score": 1.0 } ] }, { "bbox": [ 89, 166, 297, 179 ], "spans": [ { "bbox": [ 89, 166, 297, 179 ], "type": "text", "content": "的功能与 open(2)的 O_CREAT 和 O_EXCL 相当。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 184, 506, 232 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 184, 505, 196 ], "spans": [ { "bbox": [ 110, 184, 505, 196 ], "type": "text", "content": "在Linux内核中，每一个新创建的共享内存都由一个 shmid_ds的数据结构表示。如果", "score": 1.0 } ] }, { "bbox": [ 89, 201, 506, 216 ], "spans": [ { "bbox": [ 89, 201, 506, 216 ], "type": "text", "content": "函数 shmget( )成功创建了一块共享内存，则返回一个可以用于引用该共享内存的 shmid_ds", "score": 1.0 } ] }, { "bbox": [ 89, 221, 179, 232 ], "spans": [ { "bbox": [ 89, 221, 179, 232 ], "type": "text", "content": "数据结构的标识符。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 238, 506, 269 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 238, 506, 251 ], "spans": [ { "bbox": [ 110, 238, 506, 251 ], "type": "text", "content": "每一个IPC对象，系统共用一个 struct ipc_perm的数据结构来存放权限信息，以确定", "score": 1.0 } ] }, { "bbox": [ 89, 253, 275, 270 ], "spans": [ { "bbox": [ 89, 253, 275, 270 ], "type": "text", "content": "一个 ipc 操作是否可以访问该 IPC 对象。", "score": 1.0 } ] } ] }, { "bbox": [ 110, 272, 323, 285 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 270, 324, 288 ], "spans": [ { "bbox": [ 110, 270, 324, 288 ], "type": "text", "content": "（2） shmat()：连接（attach）一块共享内存", "score": 1.0 } ] } ] }, { "bbox": [ 111, 292, 181, 304 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 133, 292, 182, 305 ], "spans": [ { "bbox": [ 133, 292, 182, 305 ], "type": "text", "content": "函数声明：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 130, 312, 381, 364 ], "blocks": [ { "bbox": [ 130, 312, 381, 364 ], "lines": [ { "bbox": [ 130, 312, 381, 364 ], "spans": [ { "bbox": [ 130, 312, 381, 364 ], "type": "text", "content": "include \n#include \nvoid \\*shmat(int shmid, const void \\*shmaddr,int shmgflg);" } ] } ], "index": 8, "angle": 0, "type": "code_body" } ], "index": 8, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 111, 370, 180, 382 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 132, 370, 182, 384 ], "spans": [ { "bbox": [ 132, 370, 182, 384 ], "type": "text", "content": "输入参数：", "score": 1.0 } ] } ] }, { "bbox": [ 130, 389, 340, 402 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 133, 389, 341, 402 ], "spans": [ { "bbox": [ 133, 389, 341, 402 ], "type": "text", "content": "shmid:欲连接（attach）的共享内存的标识符。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 409, 292, 421 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 132, 409, 294, 422 ], "spans": [ { "bbox": [ 132, 409, 294, 422 ], "type": "text", "content": "shmaddr: 欲连接（attach）的地址。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 428, 223, 441 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 132, 428, 225, 442 ], "spans": [ { "bbox": [ 132, 428, 225, 442 ], "type": "text", "content": "shmflg:一个标识符。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 448, 170, 460 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 132, 448, 171, 461 ], "spans": [ { "bbox": [ 132, 448, 171, 461 ], "type": "text", "content": "返回值：", "score": 1.0 } ] } ] }, { "bbox": [ 130, 467, 446, 481 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 133, 466, 447, 481 ], "spans": [ { "bbox": [ 133, 466, 447, 481 ], "type": "text", "content": "若成功则返回已连接好的地址，否则返回-1，错误原因存在于errno。", "score": 1.0 } ] } ] }, { "bbox": [ 130, 486, 504, 519 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 132, 486, 506, 502 ], "spans": [ { "bbox": [ 132, 486, 506, 502 ], "type": "text", "content": "errno=EINVAL：参数 shmid 无效；参数 shmaddr 并非页对齐（page aligned），而参", "score": 1.0 } ] }, { "bbox": [ 133, 506, 346, 520 ], "spans": [ { "bbox": [ 133, 506, 346, 520 ], "type": "text", "content": "数 shmflg 中并未设置 SHM_RND 这个标志位。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 525, 362, 539 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 133, 526, 364, 539 ], "spans": [ { "bbox": [ 133, 526, 364, 539 ], "type": "text", "content": "ENOMEN：分配标识符或页表时，系统内存不足。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 544, 416, 558 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 133, 545, 417, 558 ], "spans": [ { "bbox": [ 133, 545, 417, 558 ], "type": "text", "content": "EACCESS：调用进程没有权限以指定的方式连接该共享内存。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 565, 159, 576 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 132, 565, 161, 578 ], "spans": [ { "bbox": [ 132, 565, 161, 578 ], "type": "text", "content": "说明：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 586, 505, 617 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 110, 587, 505, 597 ], "spans": [ { "bbox": [ 110, 587, 505, 597 ], "type": "text", "content": "函数shmat（）将以参数 shmid为标识符的共享内存连接（attach）到调用进程的数据", "score": 1.0 } ] }, { "bbox": [ 89, 604, 242, 616 ], "spans": [ { "bbox": [ 89, 604, 242, 616 ], "type": "text", "content": "段，连接的地址由shmaddr 指定。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 621, 472, 634 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 109, 621, 474, 635 ], "spans": [ { "bbox": [ 109, 621, 474, 635 ], "type": "text", "content": "参数 shmflg 除了可以设置 SHM_RND 标志位外，还可以设置 SHM_RDONLY 标志位。", "score": 1.0 } ] } ] }, { "bbox": [ 110, 638, 357, 651 ], "type": "title", "angle": 0, "index": 21, "lines": [ { "bbox": [ 110, 636, 358, 654 ], "spans": [ { "bbox": [ 110, 636, 358, 654 ], "type": "text", "content": "（3） shmdt()：断开（detach）一块共享内存的连接", "score": 1.0 } ] } ] }, { "bbox": [ 111, 657, 181, 670 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 133, 657, 182, 671 ], "spans": [ { "bbox": [ 133, 657, 182, 671 ], "type": "text", "content": "函数声明：", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 131, 677, 282, 729 ], "blocks": [ { "bbox": [ 131, 677, 282, 729 ], "lines": [ { "bbox": [ 131, 677, 282, 729 ], "spans": [ { "bbox": [ 131, 677, 282, 729 ], "type": "text", "content": "include #include int shmdt(const void \\*shmaddr);" } ] } ], "index": 23, "angle": 0, "type": "code_body" } ], "index": 23, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 111, 735, 180, 748 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 132, 735, 182, 749 ], "spans": [ { "bbox": [ 132, 735, 182, 749 ], "type": "text", "content": "输入参数：", "score": 1.0 } ] } ] }, { "bbox": [ 131, 755, 392, 768 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 133, 755, 393, 768 ], "spans": [ { "bbox": [ 133, 755, 393, 768 ], "type": "text", "content": "shmaddr：欲断开连接（detach）的共享内存的虚拟地址。", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 64 }, { "para_blocks": [ { "bbox": [ 111, 74, 170, 87 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 133, 74, 171, 89 ], "spans": [ { "bbox": [ 133, 74, 171, 89 ], "type": "text", "content": "返回值：", "score": 1.0 } ] } ] }, { "bbox": [ 107, 95, 441, 108 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 95, 442, 110 ], "spans": [ { "bbox": [ 109, 95, 442, 110 ], "type": "text", "content": "若成功则返回已连接好的地址，否则返回-1，错误原因存在于 errno 中。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 114, 452, 126 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 108, 113, 453, 127 ], "spans": [ { "bbox": [ 108, 113, 453, 127 ], "type": "text", "content": "errno=EINVAL：参数 shmaddr 无效或参数 shmaddr 地址并非共享内存地址。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 132, 137, 144 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 131, 138, 146 ], "spans": [ { "bbox": [ 109, 131, 138, 146 ], "type": "text", "content": "说明：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 149, 505, 198 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 136, 150, 504, 161 ], "spans": [ { "bbox": [ 136, 150, 504, 161 ], "type": "text", "content": "函数shmdt 从调用进程的数据段，断开地址在shmaddr的共享内存。要分离的共", "score": 1.0 } ] }, { "bbox": [ 89, 168, 506, 180 ], "spans": [ { "bbox": [ 89, 168, 506, 180 ], "type": "text", "content": "享内存必须是当前连接到调用进程地址空间的共享内存质疑，也就是说shmaddr 必须等于连", "score": 1.0 } ] }, { "bbox": [ 89, 186, 284, 197 ], "spans": [ { "bbox": [ 89, 186, 284, 197 ], "type": "text", "content": "接某个共享内存时调用 shmat时的返回值。", "score": 1.0 } ] } ] }, { "bbox": [ 110, 202, 318, 215 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 111, 200, 319, 217 ], "spans": [ { "bbox": [ 111, 200, 319, 217 ], "type": "text", "content": "（4） shmctl()：对一块共享内存的控制操作", "score": 1.0 } ] } ] }, { "bbox": [ 111, 220, 181, 232 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 133, 220, 182, 232 ], "spans": [ { "bbox": [ 133, 220, 182, 232 ], "type": "text", "content": "函数声明：", "score": 1.0 } ] } ] }, { "bbox": [ 130, 238, 221, 250 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 132, 236, 220, 252 ], "spans": [ { "bbox": [ 132, 236, 220, 252 ], "type": "text", "content": "#include", "score": 1.0 } ] } ] }, { "bbox": [ 131, 257, 225, 269 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 132, 257, 225, 271 ], "spans": [ { "bbox": [ 132, 257, 225, 271 ], "type": "text", "content": "#include", "score": 1.0 } ] } ] }, { "bbox": [ 130, 277, 362, 289 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 133, 276, 363, 290 ], "spans": [ { "bbox": [ 133, 276, 363, 290 ], "type": "text", "content": "int shmctl (int shmid, int cmd, struct shmid_ds *buff);", "score": 1.0 } ] } ] }, { "bbox": [ 111, 294, 180, 306 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 132, 293, 182, 307 ], "spans": [ { "bbox": [ 132, 293, 182, 307 ], "type": "text", "content": "输入参数：", "score": 1.0 } ] } ] }, { "bbox": [ 130, 309, 312, 322 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 133, 310, 313, 322 ], "spans": [ { "bbox": [ 133, 310, 313, 322 ], "type": "text", "content": "shmid：为欲处理的共享内存的标识符。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 325, 241, 337 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 133, 325, 242, 337 ], "spans": [ { "bbox": [ 133, 325, 242, 337 ], "type": "text", "content": "cmd：为欲进行的操作。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 341, 185, 353 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 132, 339, 187, 354 ], "spans": [ { "bbox": [ 132, 339, 187, 354 ], "type": "text", "content": "buf：缓存。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 356, 170, 368 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 133, 356, 171, 370 ], "spans": [ { "bbox": [ 133, 356, 171, 370 ], "type": "text", "content": "返回值：", "score": 1.0 } ] } ] }, { "bbox": [ 130, 371, 469, 384 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 133, 371, 470, 386 ], "spans": [ { "bbox": [ 133, 371, 470, 386 ], "type": "text", "content": "若成功则返回共享内存的标识符，否则返回-1，错误原因存在于 errno 中。", "score": 1.0 } ] } ] }, { "bbox": [ 131, 387, 440, 400 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 132, 386, 442, 401 ], "spans": [ { "bbox": [ 132, 386, 155, 401 ], "type": "text", "content": "errno", "score": 1.0 }, { "bbox": [ 155, 390, 164, 399 ], "type": "inline_equation", "content": "\\llcorner", "score": 0.8 }, { "bbox": [ 165, 386, 442, 401 ], "type": "text", "content": "EINVAL：参数 shmid 是个无效的标识符或 cmd 为无效命令。", "score": 1.0 } ] } ] }, { "bbox": [ 163, 402, 459, 431 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 165, 402, 460, 416 ], "spans": [ { "bbox": [ 165, 402, 460, 416 ], "type": "text", "content": "EFAULT：参数 cmd 为 IPC_SET 或 IPC_STAT，但是参数 buf 却", "score": 1.0 } ] }, { "bbox": [ 165, 418, 246, 431 ], "spans": [ { "bbox": [ 165, 418, 246, 431 ], "type": "text", "content": "指向无效的地址。", "score": 1.0 } ] } ] }, { "bbox": [ 163, 433, 383, 446 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 165, 433, 383, 447 ], "spans": [ { "bbox": [ 165, 433, 383, 447 ], "type": "text", "content": "EIDRM：参数shmid所指的共享内存已经删除。", "score": 1.0 } ] } ] }, { "bbox": [ 163, 449, 460, 493 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 165, 450, 459, 462 ], "spans": [ { "bbox": [ 165, 450, 459, 462 ], "type": "text", "content": "EPERM：参数 cmd 为 IPC_SET 或 IPC_RMID，但是调用进程并", "score": 1.0 } ] }, { "bbox": [ 165, 465, 461, 477 ], "spans": [ { "bbox": [ 165, 465, 461, 477 ], "type": "text", "content": "不是创建者，所有者或超级用户，并且调用进程没有授予这些组", "score": 1.0 } ] }, { "bbox": [ 165, 481, 225, 494 ], "spans": [ { "bbox": [ 165, 481, 225, 494 ], "type": "text", "content": "或域的权限。", "score": 1.0 } ] } ] }, { "bbox": [ 163, 496, 477, 509 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 164, 496, 479, 510 ], "spans": [ { "bbox": [ 164, 496, 479, 510 ], "type": "text", "content": "EACCESS：参数cmd 为 IPC_STAT，但是没有权限读写该共享内存。", "score": 1.0 } ] } ] }, { "bbox": [ 111, 512, 156, 524 ], "type": "title", "angle": 0, "index": 22, "lines": [ { "bbox": [ 116, 511, 158, 527 ], "spans": [ { "bbox": [ 116, 516, 120, 519 ], "type": "text", "content": "", "score": 0.0 }, { "bbox": [ 132, 511, 158, 527 ], "type": "text", "content": "说明", "score": 1.0 } ] } ] }, { "bbox": [ 86, 530, 505, 579 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 111, 531, 505, 543 ], "spans": [ { "bbox": [ 111, 531, 505, 543 ], "type": "text", "content": "该系统调用允许用户得到一块共享内存的相关信息，设置一块共享内存的所有者，组以", "score": 1.0 } ] }, { "bbox": [ 89, 549, 506, 560 ], "spans": [ { "bbox": [ 89, 549, 506, 560 ], "type": "text", "content": "及读写权限，或者销毁一块共享内存。以shmid为标识符的共享内存的相关信息将被放在一", "score": 1.0 } ] }, { "bbox": [ 89, 566, 248, 579 ], "spans": [ { "bbox": [ 89, 566, 248, 579 ], "type": 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"score": 1.0 } ] } ] }, { "bbox": [ 129, 340, 296, 353 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 146, 341, 298, 353 ], "spans": [ { "bbox": [ 146, 341, 298, 353 ], "type": "text", "content": "my_ls：用于显示目录中的内容。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 356, 275, 368 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 146, 356, 276, 368 ], "spans": [ { "bbox": [ 146, 356, 276, 368 ], "type": "text", "content": "my_cd：用于更改当前目录。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 371, 275, 385 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 146, 372, 276, 384 ], "spans": [ { "bbox": [ 146, 372, 276, 384 ], "type": "text", "content": "my_create：用于创建文件。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 387, 264, 399 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 146, 387, 265, 400 ], "spans": [ { "bbox": [ 146, 387, 265, 400 ], "type": "text", "content": "my_open：用于打开文件。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 402, 270, 415 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 146, 402, 271, 415 ], "spans": [ { "bbox": [ 146, 402, 271, 415 ], "type": "text", "content": "my_close：用于关闭文件。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 418, 259, 431 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 146, 418, 261, 431 ], "spans": [ { "bbox": [ 146, 418, 261, 431 ], "type": "text", "content": "my_write：用于写文件。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 433, 255, 446 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 146, 434, 255, 446 ], "spans": [ { "bbox": [ 146, 434, 255, 446 ], "type": "text", "content": "my_read：用于读文件。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 449, 255, 462 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 146, 449, 255, 462 ], "spans": [ { "bbox": [ 146, 449, 255, 462 ], "type": "text", "content": "my_rm：用于删除文件。", "score": 1.0 } ] } ] }, { "bbox": [ 129, 465, 301, 478 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 146, 465, 302, 478 ], "spans": [ { "bbox": [ 146, 465, 302, 478 ], "type": "text", "content": "my_exitsys：用于退出文件系统。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 488, 220, 501 ], "type": "title", "angle": 0, "index": 22, "lines": [ { "bbox": [ 108, 487, 220, 502 ], "spans": [ { "bbox": [ 108, 487, 220, 502 ], "type": "text", "content": "3．学时安排（12 学时）", "score": 1.0 } ] } ] }, { "bbox": [ 107, 519, 174, 532 ], "type": "title", "angle": 0, "index": 23, "lines": [ { "bbox": [ 107, 518, 176, 533 ], "spans": [ { "bbox": [ 107, 518, 176, 533 ], "type": "text", "content": "4． 开发平台", "score": 1.0 } ] } ] }, { "bbox": [ 107, 543, 289, 556 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 108, 541, 290, 558 ], "spans": [ { "bbox": [ 108, 541, 290, 558 ], "type": "text", "content": "Linux 环境，gcc，gdb，vim 或 gedit 等。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 565, 149, 578 ], "type": "title", "angle": 0, "index": 25, "lines": [ { "bbox": [ 108, 565, 149, 580 ], "spans": [ { "bbox": [ 108, 565, 149, 580 ], "type": "text", "content": "5．思考", "score": 1.0 } ] } ] }, { "bbox": [ 86, 589, 506, 665 ], "type": "list", "angle": 0, "index": 29, "blocks": [ { "bbox": [ 86, 589, 505, 617 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 111, 590, 505, 602 ], "spans": [ { "bbox": [ 111, 590, 505, 602 ], "type": "text", "content": "(1)我们的数据结构中的文件物理地址信息是使用 C 语言的指针类型、还是整型，为什", "score": 1.0 } ] }, { "bbox": [ 88, 603, 110, 620 ], "spans": [ { "bbox": [ 88, 603, 110, 620 ], "type": "text", "content": "么？", "score": 1.0 } ] } ] }, { "bbox": [ 108, 620, 387, 634 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 112, 620, 387, 634 ], "spans": [ { "bbox": [ 112, 620, 387, 634 ], "type": "text", "content": "(2)如果引入磁盘索引结点，上述实现过程需要作哪些修改？", "score": 1.0 } ] } ] }, { "bbox": [ 86, 636, 506, 665 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 111, 637, 505, 648 ], "spans": [ { "bbox": [ 111, 637, 505, 648 ], "type": "text", "content": "(3)如果设计的是一个单用户多任务文件系统，则系统需要进行哪些扩充（尤其要考虑", "score": 1.0 } ] }, { "bbox": [ 89, 653, 442, 664 ], "spans": [ { "bbox": [ 89, 653, 442, 664 ], "type": "text", "content": "读写指针问题）？如果设计的是一个多用户文件系统，则又要进行哪些扩充？", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 681, 175, 694 ], "type": "title", "angle": 0, "index": 30, "lines": [ { "bbox": [ 109, 682, 176, 694 ], "spans": [ { "bbox": [ 109, 682, 176, 694 ], "type": "text", "content": "5.2 预备知识", "score": 1.0 } ] } ] }, { "bbox": [ 113, 718, 247, 731 ], "type": "title", "angle": 0, "index": 31, "lines": [ { "bbox": [ 114, 718, 246, 733 ], "spans": [ { "bbox": [ 114, 718, 246, 733 ], "type": "text", "content": "5.2.1 FAT 文件系统介绍", "score": 1.0 } ] } ] }, { "bbox": [ 108, 750, 149, 762 ], "type": "title", "angle": 0, "index": 32, "lines": [ { "bbox": [ 108, 749, 149, 764 ], "spans": [ { "bbox": [ 108, 749, 149, 764 ], "type": "text", "content": "1．概述", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 66 }, { "para_blocks": [ { "bbox": [ 86, 76, 507, 214 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 108, 76, 504, 89 ], "spans": [ { "bbox": [ 108, 76, 504, 89 ], "type": "text", "content": "FAT文件系统是微软公司在其早期的操作系统MS-DOS及Windows9x中采用的文件系统，", "score": 1.0 } ] }, { "bbox": [ 89, 95, 505, 107 ], "spans": [ { "bbox": [ 89, 95, 505, 107 ], "type": "text", "content": "它被设计用来管理小容量的磁盘空间。FAT文件系统是以他的文件组织方式——文件分配表", "score": 1.0 } ] }, { "bbox": [ 93, 113, 505, 125 ], "spans": [ { "bbox": [ 93, 113, 505, 125 ], "type": "text", "content": "（file allocation table，FAT）命名的，文件分配表的每个表项中存放某文件的下一个盘", "score": 1.0 } ] }, { "bbox": [ 89, 132, 499, 142 ], "spans": [ { "bbox": [ 89, 132, 499, 142 ], "type": "text", "content": "块号，而该文件的起始盘块号则保存在它的文件控制块 FCB中。在文件分配表中，一般用", "score": 1.0 } ] }, { "bbox": [ 88, 148, 505, 161 ], "spans": [ { "bbox": [ 88, 148, 505, 161 ], "type": "text", "content": "FFFF来标识文件的结束；用 0000来标识某个逻辑块未被分配，即是空闲块。为了提高文件", "score": 1.0 } ] }, { "bbox": [ 89, 166, 506, 179 ], "spans": [ { "bbox": [ 89, 166, 506, 179 ], "type": "text", "content": "系统的可靠性，在逻辑磁盘上通常设置两张文件分配表，它们互为备份。此外，文件分配表", "score": 1.0 } ] }, { "bbox": [ 89, 185, 504, 196 ], "spans": [ { "bbox": [ 89, 185, 504, 196 ], "type": "text", "content": "必须存放在逻辑磁盘上的固定位置，而根目录区通常位于 FAT2之后，以便操作系统在启动", "score": 1.0 } ] }, { "bbox": [ 89, 203, 326, 215 ], "spans": [ { "bbox": [ 89, 203, 326, 215 ], "type": "text", "content": "时能够定位所需的文件，其磁盘布局如图3-1所示：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 110, 216, 431, 246 ], "blocks": [ { "bbox": [ 110, 216, 431, 246 ], "lines": [ { "bbox": [ 110, 216, 431, 246 ], "spans": [ { "bbox": [ 110, 216, 431, 246 ], "type": "table", "html": "
引导块FAT1FAT2根目录区数据区
", "image_path": "fa8c75bfbf6febaed460ddd9ce00151034952a82b7364ccd37d3153c0c5f8433.jpg" } ] } ], "index": 2, "angle": 0, "type": "table_body" } ], "index": 2 }, { "bbox": [ 176, 251, 317, 264 ], "angle": 0, "index": 3, "lines": [ { "bbox": [ 178, 252, 316, 264 ], "spans": [ { "bbox": [ 178, 252, 316, 264 ], "type": "text", "content": "图 5-1 FAT文件系统磁盘布局", "score": 1.0 } ] } ], "type": "text" }, { "bbox": [ 87, 269, 506, 319 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 110, 269, 505, 282 ], "spans": [ { "bbox": [ 110, 269, 505, 282 ], "type": "text", "content": "上述磁盘布局中，引导块中主要存放了用于描述分区的各种信息，包括逻辑块的大小、", "score": 1.0 } ] }, { "bbox": [ 89, 288, 505, 300 ], "spans": [ { "bbox": [ 89, 288, 505, 300 ], "type": "text", "content": "文件分配表的大小及位置、根目录的大小及位置等。除此之外，用于加载操作系统内核的引", "score": 1.0 } ] }, { "bbox": [ 90, 306, 211, 317 ], "spans": [ { "bbox": [ 90, 306, 211, 317 ], "type": "text", "content": "导程序也存储在引导块中。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 322, 508, 444 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 110, 324, 505, 335 ], "spans": [ { "bbox": [ 110, 324, 505, 335 ], "type": "text", "content": "FAT 文件系统家族又分为FAT12、FAT16、FAT32三种类型，这里的数字表示文件分配表", "score": 1.0 } ] }, { "bbox": [ 89, 342, 498, 354 ], "spans": [ { "bbox": [ 89, 342, 498, 354 ], "type": "text", "content": "中每个表项（即簇号）所占的位数，即FAT12中每个表项占 1.5个字节（12位），FAT16", "score": 1.0 } ] }, { "bbox": [ 89, 359, 502, 372 ], "spans": [ { "bbox": [ 89, 359, 502, 372 ], "type": "text", "content": "中每个表项占2个字节（16位），FAT32中每个表项占 4个字节（32 位）。由于 FAT文件", "score": 1.0 } ] }, { "bbox": [ 89, 377, 499, 389 ], "spans": [ { "bbox": [ 89, 377, 446, 389 ], "type": "text", "content": "系统是以簇为单位为文件分配磁盘空间的（一个簇是一组连续的扇区，通常包含", "score": 1.0 }, { "bbox": [ 447, 377, 457, 389 ], "type": "inline_equation", "content": "2 ^ { \\mathfrak { n } }", "score": 0.66 }, { "bbox": [ 458, 377, 499, 389 ], "type": "text", "content": "个扇区），", "score": 1.0 } ] }, { "bbox": [ 89, 396, 505, 407 ], "spans": [ { "bbox": [ 89, 396, 505, 407 ], "type": "text", "content": "因此，FAT32比FAT12 和FAT16支持更多的簇数、更小的簇大小和更大的磁盘容量，从而大", "score": 1.0 } ] }, { "bbox": [ 89, 414, 505, 426 ], "spans": [ { "bbox": [ 89, 414, 505, 426 ], "type": "text", "content": "大提高磁盘空间的利用率。通常，FAT12适用于小容量磁盘，如软盘；FAT16是 MS-DOS的文", "score": 1.0 } ] }, { "bbox": [ 89, 433, 418, 444 ], "spans": [ { "bbox": [ 89, 433, 418, 444 ], "type": "text", "content": "件系统；FAT32是 Windows9x 中的主要文件系统，开始支持大容量磁盘。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 453, 199, 466 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 454, 199, 466 ], "spans": [ { "bbox": [ 109, 454, 199, 466 ], "type": "text", "content": "2．文件控制块FCB", "score": 1.0 } ] } ] }, { "bbox": [ 86, 480, 505, 546 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 111, 481, 500, 492 ], "spans": [ { "bbox": [ 111, 481, 500, 492 ], "type": "text", "content": "为了正确、方便地操作文件，必须设置相应的数据结构用于存放文件的描述和控制信", "score": 1.0 } ] }, { "bbox": [ 89, 498, 505, 510 ], "spans": [ { "bbox": [ 89, 498, 505, 510 ], "type": "text", "content": "息，常用的数据结构有文件控制块（简称FCB）和索引节点（简称 i节点）。在 FAT文件系", "score": 1.0 } ] }, { "bbox": [ 89, 517, 505, 528 ], "spans": [ { "bbox": [ 89, 517, 505, 528 ], "type": "text", "content": "统中使用文件控制块。文件与文件控制块一一对应，而文件控制块的有序集合就称为文件目", "score": 1.0 } ] }, { "bbox": [ 89, 535, 295, 546 ], "spans": [ { "bbox": [ 89, 535, 295, 546 ], "type": "text", "content": "录，即一个文件控制块就是一个文件目录项。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 549, 509, 577 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 111, 550, 509, 560 ], "spans": [ { "bbox": [ 111, 550, 509, 560 ], "type": "text", "content": "虽然不同文件系统的文件控制块的内容和格式不完全相同，但通常都包括以下三类信息：", "score": 1.0 } ] }, { "bbox": [ 89, 565, 263, 577 ], "spans": [ { "bbox": [ 89, 565, 263, 577 ], "type": "text", "content": "基本信息、存取控制信息和使用信息。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 580, 506, 655 ], "type": "list", "angle": 0, "index": 12, "blocks": [ { "bbox": [ 86, 580, 506, 608 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 116, 581, 505, 592 ], "spans": [ { "bbox": [ 116, 581, 505, 592 ], "type": "text", "content": "（1）基本信息。包括文件名、用户名、文件类型、文件的物理地址、文件长度、文件", "score": 1.0 } ] }, { "bbox": [ 89, 596, 211, 608 ], "spans": [ { "bbox": [ 89, 596, 211, 608 ], "type": "text", "content": "的逻辑结构和物理结构等。", "score": 1.0 } ] } ] }, { "bbox": [ 112, 611, 467, 624 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 114, 611, 468, 624 ], "spans": [ { "bbox": [ 114, 611, 468, 624 ], "type": "text", "content": "（2）存取控制信息。一般分别给出文件主、伙伴用户、一般用户的存取权限。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 626, 506, 655 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 116, 628, 505, 639 ], "spans": [ { "bbox": [ 116, 628, 505, 639 ], "type": "text", "content": "（3）使用信息。包括文件的建立日期及时间、上次存取文件的日期及时间、当前的使", "score": 1.0 } ] }, { "bbox": [ 89, 643, 138, 655 ], "spans": [ { "bbox": [ 89, 643, 138, 655 ], "type": "text", "content": "用信息等。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 657, 506, 686 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 111, 659, 505, 670 ], "spans": [ { "bbox": [ 111, 659, 505, 670 ], "type": "text", "content": "以MS-DOS（使用 FAT16文件系统）为例，它的每个文件控制块包括32个字节，其字节", "score": 1.0 } ] }, { "bbox": [ 89, 674, 199, 687 ], "spans": [ { "bbox": [ 89, 674, 199, 687 ], "type": "text", "content": "分配情况如图3-2所示：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 112, 689, 401, 734 ], "blocks": [ { "bbox": [ 112, 689, 401, 734 ], "lines": [ { "bbox": [ 112, 689, 401, 734 ], "spans": [ { "bbox": [ 112, 689, 401, 734 ], "type": "table", "html": "
字节 8B 3B 1B 10B 2B 2B 2B 4B
文件名扩展名属性保留时间日期首块号大小
", "image_path": "6af0a7aec88b437dc381f3b39b135df7126b563e642ffa373b2993c72cae56bc.jpg" } ] } ], "index": 14, "angle": 0, "type": "table_body" } ], "index": 14 }, { "bbox": [ 165, 735, 301, 748 ], "angle": 0, "index": 15, "lines": [ { "bbox": [ 168, 736, 299, 748 ], "spans": [ { "bbox": [ 168, 736, 299, 748 ], "type": "text", "content": "图 5-2 MS-DOS 的文件控制块", "score": 1.0 } ] } ], "type": "text" }, { "bbox": [ 108, 751, 506, 765 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 110, 751, 505, 764 ], "spans": [ { "bbox": [ 110, 751, 505, 764 ], "type": "text", "content": "其中属性字段占一个字节，它的每一位用来表示该文件是否具有某种属性，如果某一位", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 67 }, { "para_blocks": [ { "bbox": [ 86, 72, 417, 85 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 89, 73, 417, 86 ], "spans": [ { "bbox": [ 89, 73, 417, 86 ], "type": "text", "content": "的值为 1，则表示该文件具有该属性。各位所表示的属性如表 3-1 所示：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 105, 101, 478, 137 ], "blocks": [ { "bbox": [ 224, 89, 334, 100 ], "lines": [ { "bbox": [ 226, 89, 334, 101 ], "spans": [ { "bbox": [ 226, 89, 334, 101 ], "type": "text", "content": "表5-1 文件属性对照表", "score": 1.0 } ] } ], "index": 2, "angle": 0, "type": "table_caption" }, { "bbox": [ 105, 101, 478, 137 ], "lines": [ { "bbox": [ 105, 101, 478, 137 ], "spans": [ { "bbox": [ 105, 101, 478, 137 ], "type": "table", "html": "
位76543210
属性保留保留存档子目录卷标系统文件隐藏只读
", "image_path": "7984fb35be11dd335935b4ebdd2f35eb4e11f76ebc6d13e2b6b3e25ca7e6eb5d.jpg" } ] } ], "index": 3, "angle": 0, "type": "table_body" } ], "index": 3 }, { "bbox": [ 108, 159, 169, 173 ], "type": "title", "angle": 0, "index": 4, "lines": [ { "bbox": [ 108, 159, 170, 173 ], "spans": [ { "bbox": [ 108, 159, 170, 173 ], "type": "text", "content": "3．根目录区", "score": 1.0 } ] } ] }, { "bbox": [ 86, 186, 504, 272 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 108, 187, 499, 199 ], "spans": [ { "bbox": [ 108, 187, 499, 199 ], "type": "text", "content": "FAT12、FAT16的根目录区是固定区域、固定大小的，位于第二个 FAT之后，如图 3-1", "score": 1.0 } ] }, { "bbox": [ 89, 205, 504, 216 ], "spans": [ { "bbox": [ 89, 205, 504, 216 ], "type": "text", "content": "所示，且占据若干连续扇区，其中 FAT12占14个扇区，一共 224个根目录项；而 FAT16占", "score": 1.0 } ] }, { "bbox": [ 88, 223, 505, 235 ], "spans": [ { "bbox": [ 88, 223, 505, 235 ], "type": "text", "content": "32个扇区，最多保存512个目录项，作为系统区的一部分。FAT32的根目录是作为文件处理", "score": 1.0 } ] }, { "bbox": [ 89, 241, 505, 253 ], "spans": [ { "bbox": [ 89, 241, 505, 253 ], "type": "text", "content": "的，采用与子目录文件相同的管理方式，其位置不是固定的，不过一般情况也是位于第二个", "score": 1.0 } ] }, { "bbox": [ 88, 259, 492, 271 ], "spans": [ { "bbox": [ 88, 259, 492, 271 ], "type": "text", "content": "FAT之后的，其大小可视需要增加，因此根目录下的文件数目不再受最多512 个的限制。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 280, 274, 294 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 114, 280, 275, 296 ], "spans": [ { "bbox": [ 114, 280, 275, 296 ], "type": "text", "content": "5.2.2 几个 C 语言库函数介绍", "score": 1.0 } ] } ] }, { "bbox": [ 86, 307, 505, 374 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 111, 308, 505, 320 ], "spans": [ { "bbox": [ 111, 308, 505, 320 ], "type": "text", "content": "由于我们的文件系统是建立在内存的虚拟磁盘上的，在退出文件系统的时候必须以一个", "score": 1.0 } ] }, { "bbox": [ 89, 326, 505, 338 ], "spans": [ { "bbox": [ 89, 326, 505, 338 ], "type": "text", "content": "文件的形式保存到磁盘上；而在启动文件系统的时候必须从磁盘上将该文件读入到内存的虚", "score": 1.0 } ] }, { "bbox": [ 89, 344, 499, 356 ], "spans": [ { "bbox": [ 89, 344, 499, 356 ], "type": "text", "content": "拟磁盘中。下面介绍几个可能会用到的C库函数，在使用这些库函数之前必须包含头文件", "score": 1.0 } ] }, { "bbox": [ 91, 360, 151, 375 ], "spans": [ { "bbox": [ 91, 360, 151, 375 ], "type": "text", "content": "“stdio.h”。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 384, 229, 397 ], "type": "title", "angle": 0, "index": 8, "lines": [ { "bbox": [ 108, 382, 229, 400 ], "spans": [ { "bbox": [ 108, 382, 229, 400 ], "type": "text", "content": "1．打开文件函数 fopen()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 411, 429, 460 ], "type": "list", "angle": 0, "index": 12, "blocks": [ { "bbox": [ 113, 411, 429, 424 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 410, 430, 425 ], "spans": [ { "bbox": [ 114, 410, 430, 425 ], "type": "text", "content": "（1）格式：FILE *fopen(const char *filename,const char *mode)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 428, 321, 442 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": 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"spans": [ { "bbox": [ 133, 638, 155, 650 ], "type": "inline_equation", "content": "\\mathrm { ^ { \\prime \\prime } a } + \\mathrm { ^ { \\prime \\prime } }", "score": 0.85 }, { "bbox": [ 156, 638, 482, 650 ], "type": "text", "content": "：功能与\"a\"相同；只是在文件末尾添加新的数据后，可以从头开始读。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 656, 502, 687 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 110, 656, 502, 670 ], "spans": [ { "bbox": [ 110, 656, 502, 670 ], "type": "text", "content": "另外，上述模式字符串中都可以加一个“b”字符，如 rb、wb、ab、rb+、wb+、ab+等", "score": 1.0 } ] }, { "bbox": [ 88, 674, 460, 687 ], "spans": [ { "bbox": [ 88, 674, 460, 687 ], "type": "text", "content": "组合，字符“b”表示 fopen() 函数打开的文件为二进制文件，而非纯文字文件。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 692, 293, 705 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 115, 692, 295, 705 ], "spans": [ { "bbox": [ 115, 692, 295, 705 ], "type": "text", "content": "（4）输出：一个指向 FILE类型的指针。", "score": 1.0 } ] } ] }, 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"type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 116, 619, 321, 632 ], "spans": [ { "bbox": [ 116, 619, 321, 632 ], "type": "text", "content": "（2）功能：用来判断是否已读取到文件末尾。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 114, 637, 205, 650 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 116, 637, 205, 650 ], "spans": [ { "bbox": [ 116, 637, 205, 650 ], "type": "text", "content": "（3）输入参数说明：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 655, 423, 685 ], "type": "list", "angle": 0, "index": 34, "blocks": [ { "bbox": [ 113, 655, 423, 667 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 114, 655, 424, 669 ], "spans": [ { "bbox": [ 114, 655, 424, 669 ], "type": "text", "content": "stream：使用fopen()打开的文件的指针，用于指示要判断的文件。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 673, 401, 685 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 115, 673, 402, 686 ], "spans": [ { "bbox": [ 115, 673, 402, 686 ], "type": "text", "content": "（4）输出：如果已读到文件尾则返回非零值，其他情况返回 0。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 695, 229, 708 ], "type": "title", "angle": 0, "index": 35, "lines": [ { "bbox": [ 108, 694, 229, 710 ], "spans": [ { "bbox": [ 108, 694, 229, 710 ], "type": "text", "content": "6．定位文件函数 fseek()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 723, 434, 753 ], "type": "list", "angle": 0, "index": 38, "blocks": [ { "bbox": [ 113, 723, 434, 735 ], "type": "text", "angle": 0, "index": 36, "lines": [ { "bbox": [ 114, 722, 436, 736 ], "spans": [ { "bbox": [ 114, 722, 436, 736 ], "type": "text", "content": "（1）格式：int fseek( FILE *stream, long offset, int origin )；", "score": 1.0 } ] } ] }, { "bbox": [ 113, 740, 336, 753 ], "type": "text", "angle": 0, "index": 37, "lines": [ { "bbox": [ 115, 740, 337, 753 ], "spans": [ { "bbox": [ 115, 740, 337, 753 ], "type": "text", "content": "（2）功能： 移动文件读写指针在文件中的位置。", "score": 1.0 } ] } ] } ], "sub_type": "text" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 69 }, { "para_blocks": [ { "bbox": [ 113, 76, 204, 88 ], "type": "title", "angle": 0, "index": 1, "lines": [ { "bbox": [ 114, 76, 205, 89 ], "spans": [ { "bbox": [ 114, 76, 205, 89 ], "type": "text", "content": "（3）输入参数说明：", "score": 1.0 } ] } ] }, { "bbox": [ 113, 94, 461, 106 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 94, 463, 107 ], "spans": [ { "bbox": [ 114, 94, 463, 107 ], "type": "text", "content": "stream：使用fopen()打开的文件的指针，用于指示要定位读写指针的文件；", "score": 1.0 } ] } ] }, { "bbox": [ 113, 112, 267, 124 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 115, 112, 268, 126 ], "spans": [ { "bbox": [ 115, 112, 268, 126 ], "type": "text", "content": "offset：位移量，以字节为单位；", "score": 1.0 } ] } ] }, { "bbox": [ 113, 130, 267, 142 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 114, 131, 268, 142 ], "spans": [ { "bbox": [ 114, 131, 268, 142 ], "type": "text", "content": "origin：初始位置，有三个常量：", "score": 1.0 } ] } ] }, { "bbox": [ 149, 148, 293, 160 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 152, 148, 294, 161 ], "spans": [ { "bbox": [ 152, 148, 294, 161 ], "type": "text", "content": "SEEK_CUR：读写指针当前位置；", "score": 1.0 } ] } ] }, { "bbox": [ 149, 166, 251, 178 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 151, 166, 252, 180 ], "spans": [ { "bbox": [ 151, 166, 252, 180 ], "type": "text", "content": "SEEK_SET：文件开头；", "score": 1.0 } ] } ] }, { "bbox": [ 149, 185, 251, 196 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 151, 184, 253, 197 ], "spans": [ { "bbox": [ 151, 184, 253, 197 ], "type": "text", "content": "SEEK_END：文件末尾。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 212, 427, 226 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 115, 211, 429, 227 ], "spans": [ { "bbox": [ 115, 211, 429, 227 ], "type": "text", "content": "当 origin 值为 SEEK_CUR 或 SEEK_END 时，参数 offset 可以为负值。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 242, 235, 254 ], "type": "title", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 243, 235, 255 ], "spans": [ { "bbox": [ 109, 243, 235, 255 ], "type": "text", "content": "5.3 实例系统的设计与实现", "score": 1.0 } ] } ] }, { "bbox": [ 86, 275, 505, 323 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 110, 275, 505, 287 ], "spans": [ { "bbox": [ 110, 275, 505, 287 ], "type": "text", "content": "本实例系统是仿照FAT16文件系统来设计实现的，但根目录没有采用FAT16的固定位置、", "score": 1.0 } ] }, { "bbox": [ 88, 293, 505, 306 ], "spans": [ { "bbox": [ 88, 293, 505, 306 ], "type": "text", "content": "固定大小的根目录区，而是以根目录文件的形式来实现的，这也是目前主流文件系统对根目", "score": 1.0 } ] }, { "bbox": [ 89, 311, 158, 324 ], "spans": [ { "bbox": [ 89, 311, 158, 324 ], "type": "text", "content": "录的处理方式。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 333, 224, 346 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 333, 225, 347 ], "spans": [ { "bbox": [ 114, 333, 225, 347 ], "type": "text", "content": "5.3.1 数据结构设计", "score": 1.0 } ] } ] }, { "bbox": [ 108, 364, 211, 377 ], "type": "title", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 364, 211, 378 ], "spans": [ { "bbox": [ 109, 364, 211, 378 ], "type": "text", "content": "1．需要包含的头文件", "score": 1.0 } ] } ] }, { "bbox": [ 113, 391, 237, 457 ], "type": "list", "angle": 0, "index": 17, "blocks": [ { "bbox": [ 113, 391, 232, 403 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 115, 391, 232, 404 ], "spans": [ { "bbox": [ 115, 391, 232, 404 ], "type": "text", "content": "（1）#include ", "score": 1.0 } ] } ] }, { "bbox": [ 113, 409, 237, 421 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 114, 408, 238, 423 ], "spans": [ { "bbox": [ 114, 408, 238, 423 ], "type": "text", "content": "（2）#include ", "score": 1.0 } ] } ] }, { "bbox": [ 113, 428, 236, 439 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 426, 238, 441 ], "spans": [ { "bbox": [ 114, 426, 238, 441 ], "type": "text", "content": "（3）#include ", "score": 1.0 } ] } ] }, { "bbox": [ 113, 445, 227, 457 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 444, 227, 459 ], "spans": [ { "bbox": [ 114, 444, 227, 459 ], "type": "text", "content": "（4）#include ", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 467, 180, 480 ], "type": "title", "angle": 0, "index": 18, "lines": [ { "bbox": [ 108, 468, 180, 481 ], "spans": [ { "bbox": [ 108, 468, 180, 481 ], "type": "text", "content": "2．定义的常量", "score": 1.0 } ] } ] }, { "bbox": [ 113, 494, 402, 597 ], "type": "list", "angle": 0, "index": 25, "blocks": [ { "bbox": [ 113, 494, 348, 507 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 494, 348, 508 ], "spans": [ { "bbox": [ 114, 494, 265, 508 ], "type": "text", "content": "（1）#define BLOCKSIZE 1024", "score": 1.0 }, { "bbox": [ 292, 494, 348, 507 ], "type": "text", "content": "磁盘块大小", "score": 1.0 } ] } ] }, { "bbox": [ 113, 512, 389, 524 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 114, 511, 389, 527 ], "spans": [ { "bbox": [ 114, 511, 207, 527 ], "type": "text", "content": "（2）#define SIZE", "score": 1.0 }, { "bbox": [ 251, 513, 389, 526 ], "type": "text", "content": "1024000 虚拟磁盘空间大小", "score": 1.0 } ] } ] }, { "bbox": [ 113, 530, 402, 542 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 528, 403, 544 ], "spans": [ { "bbox": [ 114, 528, 202, 544 ], "type": "text", "content": "（3）#define END", "score": 1.0 }, { "bbox": [ 245, 529, 276, 544 ], "type": "text", "content": "65535", "score": 1.0 }, { "bbox": [ 298, 530, 403, 543 ], "type": "text", "content": "FAT中的文件结束标志", "score": 1.0 } ] } ] }, { "bbox": [ 113, 548, 392, 560 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 114, 548, 392, 562 ], "spans": [ { "bbox": [ 114, 549, 207, 562 ], "type": "text", "content": "（4）#define FREE", "score": 1.0 }, { "bbox": [ 246, 549, 254, 560 ], "type": "text", "content": "0", "score": 1.0 }, { "bbox": [ 298, 548, 392, 561 ], "type": "text", "content": "FAT中盘块空闲标志", "score": 1.0 } ] } ] }, { "bbox": [ 113, 565, 384, 578 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 114, 566, 384, 580 ], "spans": [ { "bbox": [ 114, 566, 384, 580 ], "type": "text", "content": "（5）#define ROOTBLOCKNUM 2 根目录区所占盘块总数", "score": 1.0 } ] } ] }, { "bbox": [ 113, 584, 394, 597 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 114, 584, 395, 597 ], "spans": [ { "bbox": [ 114, 585, 243, 597 ], "type": "text", "content": "（6）#define MAXOPENFILE", "score": 1.0 }, { "bbox": [ 260, 584, 395, 597 ], "type": "text", "content": "10 最多同时打开文件个数", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 607, 169, 619 ], "type": "title", "angle": 0, "index": 26, "lines": [ { "bbox": [ 108, 607, 170, 620 ], "spans": [ { "bbox": [ 108, 607, 170, 620 ], "type": "text", "content": "3．数据结构", "score": 1.0 } ] } ] }, { "bbox": [ 113, 633, 209, 645 ], "type": "title", "angle": 0, "index": 27, "lines": [ { "bbox": [ 114, 634, 208, 647 ], "spans": [ { "bbox": [ 114, 634, 208, 647 ], "type": "text", "content": "（1）文件控制块 FCB", "score": 1.0 } ] } ] }, { "bbox": [ 108, 651, 504, 664 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 110, 652, 505, 665 ], "spans": [ { "bbox": [ 110, 652, 505, 665 ], "type": "text", "content": "用于记录文件的描述和控制信息，每个文件设置一个 FCB，它也是文件的目录项的内容。", "score": 1.0 } ] } ] }, { "bbox": [ 108, 669, 305, 682 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 109, 669, 306, 682 ], "spans": [ { "bbox": [ 109, 669, 306, 682 ], "type": "text", "content": "typedef struct FCB //仿照 FAT16 设置的", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 110, 688, 490, 755 ], "blocks": [ { "bbox": [ 110, 688, 490, 755 ], "lines": [ { "bbox": [ 110, 688, 490, 755 ], "spans": [ { "bbox": [ 110, 688, 490, 755 ], "type": "text", "content": "char filename[8]；//文件名 \nchar exname[3]；//文件扩展名 \nunsigned char attribute; //文件属性字段：为简单起见，我们只为文件设置" } ] } ], "index": 30, "angle": 0, "type": "code_body" } ], "index": 30, "sub_type": "code", "guess_lang": "txt" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 70 }, { "para_blocks": [ { "type": "code", "bbox": [ 108, 75, 502, 216 ], "blocks": [ { "bbox": [ 108, 75, 502, 216 ], "lines": [ { "bbox": [ 108, 75, 502, 216 ], "spans": [ { "bbox": [ 108, 75, 502, 216 ], "type": "text", "content": "//了两种属性：值为0时表示目录文件，值为1时表示数据文件 \nunsigned short time;//文件创建时间 \nunsigned short data;//文件创建日期 \nunsigned short first;//文件起始盘块号 \nunsigned long length;//文件长度（字节数） \nchar free; //表示目录项是否为空，若值为0，表示空，值为1，表示已分配 \n}fcb;" } ] } ], "index": 1, "angle": 0, "type": "code_body" } ], "index": 1, "sub_type": "code", "guess_lang": "txt" }, { "bbox": [ 113, 238, 210, 251 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 115, 238, 209, 251 ], "spans": [ { "bbox": [ 115, 238, 209, 251 ], "type": "text", "content": "（2）文件分配表 FAT", "score": 1.0 } ] } ] }, { "bbox": [ 86, 255, 507, 359 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 110, 257, 504, 269 ], "spans": [ { "bbox": [ 110, 257, 504, 269 ], "type": "text", "content": "在本实例中，文件分配表有两个作用：一是记录磁盘上每个文件所占据的磁盘块的块号；", "score": 1.0 } ] }, { "bbox": [ 89, 275, 506, 286 ], "spans": [ { "bbox": [ 89, 275, 506, 286 ], "type": "text", "content": "二是记录磁盘上哪些块已经分配出去了，哪些块是空闲的，即起到了位示图的作用。若FAT", "score": 1.0 } ] }, { "bbox": [ 89, 293, 504, 304 ], "spans": [ { "bbox": [ 89, 293, 504, 304 ], "type": "text", "content": "中某个表项的值为FREE，则表示该表项所对应的磁盘块是空闲的；若某个表项的值为 END，", "score": 1.0 } ] }, { "bbox": [ 89, 310, 505, 322 ], "spans": [ { "bbox": [ 89, 310, 505, 322 ], "type": "text", "content": "则表示所对应的磁盘块是某文件的最后一个磁盘块；若某个表项的值是其他值，则该值表示", "score": 1.0 } ] }, { "bbox": [ 89, 328, 505, 341 ], "spans": [ { "bbox": [ 89, 328, 505, 341 ], "type": "text", "content": "某文件的下一个磁盘块的块号。为了提高系统的可靠性，本实例中设置了两张 FAT表，它们", "score": 1.0 } ] }, { "bbox": [ 89, 347, 263, 359 ], "spans": [ { "bbox": [ 89, 347, 263, 359 ], "type": "text", "content": "互为备份，每个FAT占据两个磁盘块。", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 364, 226, 431 ], "blocks": [ { "bbox": [ 108, 364, 226, 431 ], "lines": [ { "bbox": [ 108, 364, 226, 431 ], "spans": [ { "bbox": [ 108, 364, 226, 431 ], "type": "text", "content": "typedef struct FAT \n{ unsigned short id; }fat;" } ] } ], "index": 4, "angle": 0, "type": "code_body" } ], "index": 4, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 113, 454, 256, 466 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 454, 256, 467 ], "spans": [ { "bbox": [ 114, 454, 256, 467 ], "type": "text", "content": "（3）用户打开文件表 USEROPEN", "score": 1.0 } ] } ] }, { "bbox": [ 86, 470, 507, 593 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 472, 506, 485 ], "spans": [ { "bbox": [ 110, 472, 506, 485 ], "type": "text", "content": "当打开一个文件时，必须将文件的目录项中的所有内容全部复制到内存中，同时还要记", "score": 1.0 } ] }, { "bbox": [ 89, 490, 506, 502 ], "spans": [ { "bbox": [ 89, 490, 506, 502 ], "type": "text", "content": "录有关文件操作的动态信息，如读写指针的值等。在本实例中实现的是一个用于单用户单任", "score": 1.0 } ] }, { "bbox": [ 89, 508, 505, 520 ], "spans": [ { "bbox": [ 89, 508, 505, 520 ], "type": "text", "content": "务系统的文件系统，为简单起见，我们把用户文件描述符表和内存 FCB表合在一起，称为用", "score": 1.0 } ] }, { "bbox": [ 89, 526, 505, 537 ], "spans": [ { "bbox": [ 89, 526, 505, 537 ], "type": "text", "content": "户打开文件表，表项数目为 10，即一个用户最多可同时打开 10 个文件。然后用一个数组来", "score": 1.0 } ] }, { "bbox": [ 88, 544, 505, 556 ], "spans": [ { "bbox": [ 88, 544, 505, 556 ], "type": "text", "content": "描述，则数组下标即某个打开文件的描述符。另外，我们在用户打开文件表中还设置了一个", "score": 1.0 } ] }, { "bbox": [ 89, 562, 505, 575 ], "spans": [ { "bbox": [ 89, 562, 505, 575 ], "type": "text", "content": "字段“char dir[80]”，用来记录每个打开文件所在的目录名，以方便用户打开不同目录下", "score": 1.0 } ] }, { "bbox": [ 89, 581, 221, 592 ], "spans": [ { "bbox": [ 89, 581, 221, 592 ], "type": "text", "content": "具有相同文件名的不同文件。", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 86, 597, 505, 700 ], "blocks": [ { "bbox": [ 86, 597, 505, 700 ], "lines": [ { "bbox": [ 86, 597, 505, 700 ], "spans": [ { "bbox": [ 86, 597, 505, 700 ], "type": "text", "content": "typedef struct USEROPEN \n{ char filename[8]; //文件名 char exname[3];//文件扩展名 unsigned char attribute;//文件属性：值为0时表示目录文件，值为1时表示数据文件" } ] } ], "index": 7, "angle": 0, "type": "code_body" } ], "index": 7, "sub_type": "code", "guess_lang": "c" }, { "type": "code", "bbox": [ 128, 705, 326, 756 ], "blocks": [ { "bbox": [ 128, 705, 326, 756 ], "lines": [ { "bbox": [ 128, 705, 326, 756 ], "spans": [ { "bbox": [ 128, 705, 326, 756 ], "type": "text", "content": "unsigned short time; //文件创建时间 \nunsigned short data; //文件创建日期 \nunsigned short first; //文件起始盘块号" } ] } ], "index": 8, "angle": 0, "type": "code_body" } ], "index": 8, "sub_type": "code", "guess_lang": "txt" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 71 }, { "para_blocks": [ { "bbox": [ 86, 76, 503, 106 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 130, 76, 505, 89 ], "spans": [ { "bbox": [ 130, 76, 505, 89 ], "type": "text", "content": "unsigned long length;//文件长度（对数据文件是字节数，对目录文件可以是目", "score": 1.0 } ] }, { "bbox": [ 88, 93, 138, 108 ], "spans": [ { "bbox": [ 88, 93, 138, 108 ], "type": "text", "content": "录项个数）", "score": 1.0 } ] } ] }, { "bbox": [ 127, 111, 489, 143 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 130, 112, 489, 125 ], "spans": [ { "bbox": [ 130, 112, 489, 125 ], "type": "text", "content": "char free；//表示目录项是否为空，若值为0，表示空，值为1，表示已分配", "score": 1.0 } ] }, { "bbox": [ 131, 130, 296, 143 ], "spans": [ { "bbox": [ 131, 130, 296, 143 ], "type": "text", "content": "//前面内容是文件的 FCB中的内容。", "score": 1.0 } ] } ] }, { "bbox": [ 127, 148, 504, 179 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 131, 148, 505, 160 ], "spans": [ { "bbox": [ 131, 148, 505, 160 ], "type": "text", "content": "// 下面设置的dirno和diroff记录了相应打开文件的目录项在父目录文件中的位", "score": 1.0 } ] }, { "bbox": [ 131, 167, 468, 179 ], "spans": [ { "bbox": [ 131, 167, 468, 179 ], "type": "text", "content": "置，//这样如果该文件的fcb 被修改了，则要写回父目录文件时比较方便", "score": 1.0 } ] } ] }, { "bbox": [ 129, 184, 426, 196 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 130, 184, 427, 198 ], "spans": [ { "bbox": [ 130, 184, 427, 198 ], "type": "text", "content": "int dirno; //相应打开文件的目录项在父目录文件中的盘块号", "score": 1.0 } ] } ] }, { "bbox": [ 129, 201, 504, 215 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 130, 202, 506, 216 ], "spans": [ { "bbox": [ 130, 202, 506, 216 ], "type": "text", "content": "int diroff;// 相应打开文件的目录项在父目录文件的dirno盘块中的目录项序号", "score": 1.0 } ] } ] }, { "bbox": [ 86, 220, 504, 251 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 130, 221, 504, 232 ], "spans": [ { "bbox": [ 130, 221, 504, 232 ], "type": "text", "content": "char dir[MAXOPENFILE][80]; //相应打开文件所在的目录名，这样方便快速检查", "score": 1.0 } ] }, { "bbox": [ 90, 239, 205, 248 ], "spans": [ { "bbox": [ 90, 239, 205, 248 ], "type": "text", "content": "出指定文件是否已经打开", "score": 1.0 } ] } ] }, { "bbox": [ 129, 256, 317, 269 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 130, 257, 316, 269 ], "spans": [ { "bbox": [ 130, 257, 316, 269 ], "type": "text", "content": "int count; //读写指针在文件中的位置", "score": 1.0 } ] } ] }, { "bbox": [ 127, 274, 500, 287 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 130, 274, 501, 288 ], "spans": [ { "bbox": [ 130, 274, 501, 288 ], "type": "text", "content": "char fcbstate; //是否修改了文件的 FCB 的内容，如果修改了置为 1，否则为 0", "score": 1.0 } ] } ] }, { "bbox": [ 86, 291, 504, 322 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 131, 292, 506, 305 ], "spans": [ { "bbox": [ 131, 292, 506, 305 ], "type": "text", "content": "char topenfile; //表示该用户打开表项是否为空，若值为0，表示为空，否则表", "score": 1.0 } ] }, { "bbox": [ 88, 310, 195, 323 ], "spans": [ { "bbox": [ 88, 310, 195, 323 ], "type": "text", "content": "示已被某打开文件占据", "score": 1.0 } ] } ] }, { "bbox": [ 108, 328, 163, 341 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 327, 165, 343 ], "spans": [ { "bbox": [ 109, 327, 165, 343 ], "type": "text", "content": "}useropen;", "score": 1.0 } ] } ] }, { "bbox": [ 113, 364, 204, 376 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 363, 204, 378 ], "spans": [ { "bbox": [ 114, 363, 204, 378 ], "type": "text", "content": "（4）引导块 BLOCK0", "score": 1.0 } ] } ] }, { "bbox": [ 86, 381, 505, 449 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 110, 382, 505, 394 ], "spans": [ { "bbox": [ 110, 382, 505, 394 ], "type": "text", "content": "在引导块中主要存放逻辑磁盘的相关描述信息，比如磁盘块大小、磁盘块数量、文件分", "score": 1.0 } ] }, { "bbox": [ 89, 401, 505, 412 ], "spans": [ { "bbox": [ 89, 401, 505, 412 ], "type": "text", "content": "配表、根目录区、数据区在磁盘上的起始位置等。如果是引导盘，还要存放操作系统的引导", "score": 1.0 } ] }, { "bbox": [ 89, 418, 505, 430 ], "spans": [ { "bbox": [ 89, 418, 505, 430 ], "type": "text", "content": "信息。本实例是在内存的虚拟磁盘中创建一个文件系统，因此所包含的内容比较少，只有磁", "score": 1.0 } ] }, { "bbox": [ 89, 436, 400, 449 ], "spans": [ { "bbox": [ 89, 436, 400, 449 ], "type": "text", "content": "盘块大小、磁盘块数量、数据区开始位置、根目录文件开始位置等。", "score": 1.0 } ] } ] }, { "type": "code", "bbox": [ 108, 454, 462, 575 ], "blocks": [ { "bbox": [ 108, 454, 462, 575 ], "lines": [ { "bbox": [ 108, 454, 462, 575 ], "spans": [ { "bbox": [ 108, 454, 462, 575 ], "type": "text", "content": "typedef struct BLOCK0 //引导块内容 \n{ //存储一些描述信息，如磁盘块大小、磁盘块数量、最多打开文件数等、char information[200]; unsigned short root; //根目录文件的起始盘块号 unsigned char *startblock; //虚拟磁盘上数据区开始位置}block0;" } ] } ], "index": 13, "angle": 0, "type": "code_body" } ], "index": 13, "sub_type": "code", "guess_lang": "c" }, { "bbox": [ 128, 602, 211, 614 ], "type": "title", "angle": 0, "index": 14, "lines": [ { "bbox": [ 130, 602, 211, 615 ], "spans": [ { "bbox": [ 130, 602, 211, 615 ], "type": "text", "content": "4．全局变量定义", "score": 1.0 } ] } ] }, { "bbox": [ 86, 629, 504, 731 ], "type": "list", "angle": 0, "index": 20, "blocks": [ { "bbox": [ 113, 629, 384, 641 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 629, 384, 643 ], "spans": [ { "bbox": [ 114, 629, 384, 643 ], "type": "text", "content": "（1）unsigned char *myvhard： 指向虚拟磁盘的起始地址", "score": 1.0 } ] } ] }, { "bbox": [ 113, 647, 436, 659 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 647, 437, 661 ], "spans": [ { "bbox": [ 114, 647, 322, 661 ], "type": "text", "content": "（2）useropen openfilelist[MAXOPENFILE]：", "score": 1.0 }, { "bbox": [ 339, 647, 437, 660 ], "type": "text", "content": "用户打开文件表数组", "score": 1.0 } ] } ] }, { "bbox": [ 86, 665, 504, 695 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 114, 664, 505, 678 ], "spans": [ { "bbox": [ 114, 664, 505, 678 ], "type": "text", "content": "（3）useropen *ptrcurdir： 指向用户打开文件表中的当前目录所在打开文件表项的", "score": 1.0 } ] }, { "bbox": [ 88, 681, 117, 697 ], "spans": [ { "bbox": [ 88, 681, 117, 697 ], "type": "text", "content": "位置；", "score": 1.0 } ] } ] }, { "bbox": [ 113, 701, 468, 713 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 114, 701, 469, 714 ], "spans": [ { "bbox": [ 114, 701, 242, 714 ], "type": "text", "content": "（4）char currentdir[80]：", "score": 1.0 }, { "bbox": [ 273, 701, 469, 714 ], "type": "text", "content": "记录当前目录的目录名（包括目录的路径）", "score": 1.0 } ] } ] }, { "bbox": [ 113, 719, 421, 731 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 718, 421, 734 ], "spans": [ { "bbox": [ 114, 718, 253, 734 ], "type": "text", "content": "（5）unsigned char* startp：", "score": 1.0 }, { "bbox": [ 273, 719, 421, 731 ], "type": "text", "content": "记录虚拟磁盘上数据区开始位置", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 740, 211, 754 ], "type": "title", "angle": 0, "index": 21, "lines": [ { "bbox": [ 109, 740, 212, 755 ], "spans": [ { "bbox": [ 109, 740, 212, 755 ], "type": "text", "content": "5．虚拟磁盘空间布局", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 369, 52 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 369, 53 ], "spans": [ { "bbox": [ 224, 42, 369, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 72 }, { "para_blocks": [ { "bbox": [ 86, 76, 506, 161 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 110, 77, 505, 89 ], "spans": [ { "bbox": [ 110, 77, 505, 89 ], "type": "text", "content": "由于真正的磁盘操作需要涉及到设备的驱动程序，所以本实例是在内存中申请一块空间", "score": 1.0 } ] }, { "bbox": [ 89, 95, 503, 106 ], "spans": [ { "bbox": [ 89, 95, 503, 106 ], "type": "text", "content": "作为虚拟磁盘使用，我们的文件系统就建立在这个虚拟磁盘上。虚拟磁盘一共划分成 1000", "score": 1.0 } ] }, { "bbox": [ 89, 113, 504, 125 ], "spans": [ { "bbox": [ 89, 113, 504, 125 ], "type": "text", "content": "个磁盘块，每个块1024个字节，其布局格式是模仿FAT文件系统设计的，其中引导块占一", "score": 1.0 } ] }, { "bbox": [ 89, 130, 504, 142 ], "spans": [ { "bbox": [ 89, 130, 504, 142 ], "type": "text", "content": "个盘块，两张FAT各占 2个盘块，剩下的空间全部是数据区，在对虚拟磁盘进行格式化的时", "score": 1.0 } ] }, { "bbox": [ 89, 148, 471, 161 ], "spans": [ { "bbox": [ 89, 148, 471, 161 ], "type": "text", "content": "候，将把数据区第1块（即虚拟磁盘的第 6 块）分配给根目录文件，如图3-3 所示：", "score": 1.0 } ] } ] }, { "type": "table", "bbox": [ 111, 163, 459, 206 ], "blocks": [ { "bbox": [ 111, 163, 459, 206 ], "lines": [ { "bbox": [ 111, 163, 459, 206 ], "spans": [ { "bbox": [ 111, 163, 459, 206 ], "type": "table", "html": "
块数 1块 2块 2块 995块
引导块FAT1FAT2数据区
", "image_path": "dc336a5d1be7e2ccee3277b29a4afd7999c449358f141fe8629e52752ef9f5d4.jpg" } ] } ], "index": 2, "angle": 0, "type": "table_body" } ], "index": 2 }, { "bbox": [ 191, 213, 314, 226 ], "angle": 0, "index": 3, "lines": [ { "bbox": [ 195, 213, 313, 225 ], "spans": [ { "bbox": [ 195, 213, 313, 225 ], "type": "text", "content": "图5-3 虚拟磁盘空间布局", "score": 1.0 } ] } ], "type": "text" }, { "bbox": [ 87, 231, 506, 262 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 111, 232, 505, 243 ], "spans": [ { "bbox": [ 111, 232, 505, 243 ], "type": "text", "content": "当然，也可以仿照 FAT16文件系统，设置根目录区，其位置紧跟第2张 FAT 后面，大小", "score": 1.0 } ] }, { "bbox": [ 89, 248, 379, 262 ], "spans": [ { "bbox": [ 89, 248, 379, 262 ], "type": "text", "content": "也是固定的，这个思路相对要简单一点，请同学们自己去实现。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 270, 285, 285 ], "type": "title", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 270, 286, 285 ], "spans": [ { "bbox": [ 114, 270, 286, 285 ], "type": "text", "content": "5.3.2 实例主要命令及函数设计", "score": 1.0 } ] } ] }, { "bbox": [ 108, 302, 213, 316 ], "type": "title", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 301, 213, 317 ], "spans": [ { "bbox": [ 109, 301, 213, 317 ], "type": "text", "content": "1．系统主函数 main()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 329, 267, 449 ], "type": "list", "angle": 0, "index": 14, "blocks": [ { "bbox": [ 113, 329, 202, 341 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 328, 201, 343 ], "spans": [ { "bbox": [ 114, 328, 201, 343 ], "type": "text", "content": "（1）对应命令：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 347, 222, 359 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 347, 222, 359 ], "spans": [ { "bbox": [ 114, 347, 222, 359 ], "type": "text", "content": "（2）命令调用格式：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 364, 267, 377 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 114, 363, 268, 380 ], "spans": [ { "bbox": [ 114, 363, 268, 380 ], "type": "text", "content": "（3）函数设计格式：void main()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 383, 221, 395 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 114, 383, 221, 396 ], "spans": [ { "bbox": [ 114, 383, 221, 396 ], "type": "text", "content": "（4）功能：系统主函数", "score": 1.0 } ] } ] }, { "bbox": [ 113, 401, 180, 413 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 401, 180, 415 ], "spans": [ { "bbox": [ 114, 401, 180, 415 ], "type": "text", "content": "（5）输入：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 418, 180, 431 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 418, 180, 433 ], "spans": [ { "bbox": [ 114, 418, 180, 433 ], "type": "text", "content": "（6）输出：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 437, 225, 449 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 114, 437, 226, 449 ], "spans": [ { "bbox": [ 114, 437, 226, 449 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 454, 456, 576 ], "type": "list", "angle": 0, "index": 22, "blocks": [ { "bbox": [ 107, 454, 288, 467 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 109, 454, 288, 468 ], "spans": [ { "bbox": [ 109, 454, 122, 467 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.85 }, { "bbox": [ 123, 455, 288, 468 ], "type": "text", "content": "对前面定义的全局变量进行初始化；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 473, 270, 485 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 109, 472, 271, 486 ], "spans": [ { "bbox": [ 109, 472, 122, 485 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.87 }, { "bbox": [ 122, 472, 271, 486 ], "type": "text", "content": "调用 startsys()进入文件系统；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 491, 340, 503 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 491, 340, 503 ], "spans": [ { "bbox": [ 109, 491, 122, 503 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.87 }, { "bbox": [ 122, 491, 340, 503 ], "type": "text", "content": "列出文件系统提供的各项功能及命令调用格式；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 508, 309, 521 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 508, 309, 523 ], "spans": [ { "bbox": [ 109, 508, 122, 521 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.85 }, { "bbox": [ 122, 509, 309, 523 ], "type": "text", "content": "显示命令行提示符，等待用户输入命令；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 527, 299, 539 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 526, 299, 540 ], "spans": [ { "bbox": [ 109, 526, 122, 539 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.86 }, { "bbox": [ 122, 527, 299, 540 ], "type": "text", "content": "将用户输入的命令保存到一个 buf中；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 544, 456, 557 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 109, 544, 457, 558 ], "spans": [ { "bbox": [ 109, 544, 122, 557 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.86 }, { "bbox": [ 122, 545, 457, 558 ], "type": "text", "content": "对buf中的内容进行命令解析，并调用相应的函数执行用户键入的命令；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 562, 382, 576 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 109, 562, 384, 577 ], "spans": [ { "bbox": [ 109, 563, 122, 575 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.85 }, { "bbox": [ 122, 562, 367, 577 ], "type": "text", "content": "如果命令不是“my_exitsys”，则命令执行完毕后转", "score": 1.0 }, { "bbox": [ 367, 563, 379, 575 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.81 }, { "bbox": [ 379, 562, 384, 577 ], "type": "text", "content": "。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 585, 265, 598 ], "type": "title", "angle": 0, "index": 23, "lines": [ { "bbox": [ 107, 582, 267, 601 ], "spans": [ { "bbox": [ 107, 582, 267, 601 ], "type": "text", "content": "2. 进入文件系统函数 startsys()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 612, 498, 732 ], "type": "list", "angle": 0, "index": 31, "blocks": [ { "bbox": [ 113, 612, 201, 624 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 114, 612, 201, 625 ], "spans": [ { "bbox": [ 114, 612, 201, 625 ], "type": "text", "content": "（1）对应命令：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 629, 221, 642 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 114, 629, 222, 644 ], "spans": [ { "bbox": [ 114, 629, 222, 644 ], "type": "text", "content": "（2）命令调用格式：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 648, 288, 660 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 114, 646, 289, 663 ], "spans": [ { "bbox": [ 114, 646, 289, 663 ], "type": "text", "content": "（3）函数设计格式：void startsys()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 666, 498, 678 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 115, 666, 500, 678 ], "spans": [ { "bbox": [ 115, 666, 500, 678 ], "type": "text", "content": "（4）功能：由main()函数调用，进入并初始化我们所建立的文件系统，以供用户使用。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 684, 180, 696 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 114, 683, 180, 698 ], "spans": [ { "bbox": [ 114, 683, 180, 698 ], "type": "text", "content": "（5）输入：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 702, 183, 714 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 114, 701, 185, 716 ], "spans": [ { "bbox": [ 114, 701, 185, 716 ], "type": "text", "content": "（6）输出：无。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 719, 224, 732 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 114, 719, 226, 733 ], "spans": [ { "bbox": [ 114, 719, 226, 733 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 738, 214, 750 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 109, 737, 215, 751 ], "spans": [ { "bbox": [ 109, 737, 122, 751 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.83 }, { "bbox": [ 123, 739, 215, 751 ], "type": "text", "content": "申请虚拟磁盘空间；", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 73 }, { "para_blocks": [ { "bbox": [ 86, 75, 506, 323 ], "type": "list", "angle": 0, "index": 9, "blocks": [ { "bbox": [ 86, 75, 506, 107 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 76, 505, 89 ], "spans": [ { "bbox": [ 109, 76, 122, 89 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.82 }, { "bbox": [ 123, 76, 431, 89 ], "type": "text", "content": "使用c语言的库函数fopen()打开myfsys文件：若文件存在，则转", "score": 1.0 }, { "bbox": [ 431, 76, 443, 89 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.85 }, { "bbox": [ 443, 76, 505, 89 ], "type": "text", "content": "；若文件不存", "score": 1.0 } ] }, { "bbox": [ 88, 93, 185, 108 ], "spans": [ { "bbox": [ 88, 93, 173, 108 ], "type": "text", "content": "在，则创建之，转", "score": 1.0 }, { "bbox": [ 173, 94, 185, 106 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.85 } ] } ] }, { "bbox": [ 86, 111, 506, 161 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 109, 111, 504, 125 ], "spans": [ { "bbox": [ 109, 111, 122, 125 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.84 }, { "bbox": [ 123, 112, 504, 125 ], "type": "text", "content": "使用c语言的库函数fread()读入 myfsys 文件内容到用户空间中的一个缓冲区中，", "score": 1.0 } ] }, { "bbox": [ 89, 130, 506, 143 ], "spans": [ { "bbox": [ 89, 131, 473, 143 ], "type": "text", "content": "并判断其开始的8个字节内容是否为“10101010”（文件系统魔数），如果是，则转", "score": 1.0 }, { "bbox": [ 473, 130, 485, 142 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.86 }, { "bbox": [ 485, 131, 506, 143 ], "type": "text", "content": "；否", "score": 1.0 } ] }, { "bbox": [ 88, 148, 127, 162 ], "spans": [ { "bbox": [ 88, 148, 110, 162 ], "type": "text", "content": "则转", "score": 1.0 }, { "bbox": [ 110, 148, 121, 160 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.87 }, { "bbox": [ 122, 148, 127, 162 ], "type": "text", "content": "；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 165, 412, 179 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 165, 411, 180 ], "spans": [ { "bbox": [ 109, 166, 122, 179 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.86 }, { "bbox": [ 122, 165, 398, 180 ], "type": "text", "content": "将上述缓冲区中的内容复制到内存中的虚拟磁盘空间中；转", "score": 1.0 }, { "bbox": [ 398, 166, 411, 179 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.83 } ] } ] }, { "bbox": [ 86, 184, 498, 216 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 184, 498, 197 ], "spans": [ { "bbox": [ 109, 184, 122, 196 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.86 }, { "bbox": [ 122, 184, 498, 197 ], "type": "text", "content": "在屏幕上显示“myfsys文件系统不存在，现在开始创建文件系统”信息，并调用", "score": 1.0 } ] }, { "bbox": [ 87, 202, 395, 215 ], "spans": [ { "bbox": [ 87, 202, 157, 215 ], "type": "text", "content": "my_format()对", "score": 1.0 }, { "bbox": [ 157, 202, 169, 215 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.86 }, { "bbox": [ 169, 202, 377, 215 ], "type": "text", "content": "中申请到的虚拟磁盘空间进行格式化操作。转", "score": 1.0 }, { "bbox": [ 377, 202, 389, 214 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.86 }, { "bbox": [ 389, 202, 395, 215 ], "type": "text", "content": "；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 220, 354, 233 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 109, 220, 353, 234 ], "spans": [ { "bbox": [ 109, 220, 122, 232 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.85 }, { "bbox": [ 122, 220, 340, 234 ], "type": "text", "content": "将虚拟磁盘中的内容保存到 myfsys 文件中；转", "score": 1.0 }, { "bbox": [ 340, 220, 353, 232 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.84 } ] } ] }, { "bbox": [ 107, 238, 350, 252 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 237, 349, 253 ], "spans": [ { "bbox": [ 109, 238, 122, 250 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.86 }, { "bbox": [ 122, 237, 349, 253 ], "type": "text", "content": "使用 c 语言的库函数 fclose()关闭 myfsys 文件；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 255, 506, 305 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 255, 504, 269 ], "spans": [ { "bbox": [ 109, 255, 122, 269 ], "type": "inline_equation", "content": "\\textcircled{8}", "score": 0.86 }, { "bbox": [ 123, 257, 504, 268 ], "type": "text", "content": "初始化用户打开文件表，将表项 0分配给根目录文件使用，并填写根目录文件的相", "score": 1.0 } ] }, { "bbox": [ 88, 274, 502, 287 ], "spans": [ { "bbox": [ 88, 274, 502, 287 ], "type": "text", "content": "关信息，由于根目录没有上级目录，所以表项中的dirno和diroff分别置为5（根目录所", "score": 1.0 } ] }, { "bbox": [ 89, 293, 397, 304 ], "spans": [ { "bbox": [ 89, 293, 397, 304 ], "type": "text", "content": "在起始块号）和0；并将ptrcurdir指针指向该用户打开文件表项。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 310, 247, 323 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 310, 247, 322 ], "spans": [ { "bbox": [ 109, 310, 122, 322 ], "type": "inline_equation", "content": "\\textcircled{9}", "score": 0.82 }, { "bbox": [ 122, 310, 247, 322 ], "type": "text", "content": "将当前目录设置为根目录。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 332, 261, 346 ], "type": "title", "angle": 0, "index": 10, "lines": [ { "bbox": [ 108, 330, 261, 348 ], "spans": [ { "bbox": [ 108, 330, 261, 348 ], "type": "text", "content": "3．磁盘格式化函数 my_format()", "score": 1.0 } ] } ] }, { "bbox": [ 112, 359, 499, 461 ], "type": "list", "angle": 0, "index": 17, "blocks": [ { "bbox": [ 113, 359, 238, 371 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 358, 238, 374 ], "spans": [ { "bbox": [ 114, 358, 238, 374 ], "type": "text", "content": "（1）对应命令：my_format", "score": 1.0 } ] } ] }, { "bbox": [ 113, 377, 258, 390 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 375, 259, 391 ], "spans": [ { "bbox": [ 114, 375, 259, 391 ], "type": "text", "content": "（2）命令调用格式：my_format", "score": 1.0 } ] } ] }, { "bbox": [ 113, 395, 294, 407 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 114, 393, 295, 410 ], "spans": [ { "bbox": [ 114, 393, 295, 410 ], "type": "text", "content": "（3）函数设计格式：void my_format()", "score": 1.0 } ] } ] }, { "bbox": [ 112, 412, 499, 426 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 115, 413, 499, 426 ], "spans": [ { "bbox": [ 115, 413, 499, 426 ], "type": "text", "content": "（4）功能：对虚拟磁盘进行格式化，布局虚拟磁盘，建立根目录文件（或根目录区）。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 431, 180, 444 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 431, 180, 445 ], "spans": [ { "bbox": [ 114, 431, 180, 445 ], "type": "text", "content": "（5）输入：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 449, 184, 461 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 449, 185, 463 ], "spans": [ { "bbox": [ 114, 449, 185, 463 ], "type": "text", "content": "（6）输出：无。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 113, 467, 226, 480 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 115, 467, 226, 480 ], "spans": [ { "bbox": [ 115, 467, 226, 480 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 485, 506, 642 ], "type": "list", "angle": 0, "index": 22, "blocks": [ { "bbox": [ 87, 485, 500, 534 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 485, 474, 497 ], "spans": [ { "bbox": [ 109, 485, 122, 497 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.83 }, { "bbox": [ 123, 486, 474, 497 ], "type": "text", "content": "将虚拟磁盘第一个块作为引导块，开始的 8个字节是文件系统的魔数，记为", "score": 1.0 } ] }, { "bbox": [ 93, 503, 500, 515 ], "spans": [ { "bbox": [ 93, 503, 500, 515 ], "type": "text", "content": "“10101010”；在之后写入文件系统的描述信息，如 FAT表大小及位置、根目录大小及位置、", "score": 1.0 } ] }, { "bbox": [ 89, 521, 303, 533 ], "spans": [ { "bbox": [ 89, 521, 303, 533 ], "type": "text", "content": "盘块大小、盘块数量、数据区开始位置等信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 539, 506, 587 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 109, 539, 505, 551 ], "spans": [ { "bbox": [ 109, 539, 122, 551 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.81 }, { "bbox": [ 123, 539, 505, 551 ], "type": "text", "content": "在引导块后建立两张完全一样的 FAT表，用于记录文件所占据的磁盘块及管理虚拟", "score": 1.0 } ] }, { "bbox": [ 89, 558, 505, 569 ], "spans": [ { "bbox": [ 89, 558, 505, 569 ], "type": "text", "content": "磁盘块的分配，每个FAT占据两个磁盘块；对于每个 FAT中，前面5 个块设置为已分配，后", "score": 1.0 } ] }, { "bbox": [ 89, 575, 201, 587 ], "spans": [ { "bbox": [ 89, 575, 201, 587 ], "type": "text", "content": "面995个块设置为空闲；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 592, 506, 642 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 109, 592, 505, 605 ], "spans": [ { "bbox": [ 109, 592, 122, 605 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.84 }, { "bbox": [ 123, 594, 505, 605 ], "type": "text", "content": "在第二张FAT 后创建根目录文件 root，将数据区的第 1 块（即虚拟磁盘的第 6 块）", "score": 1.0 } ] }, { "bbox": [ 88, 609, 506, 624 ], "spans": [ { "bbox": [ 88, 609, 506, 624 ], "type": "text", "content": "分配给根目录文件，在该磁盘上创建两个特殊的目录项：“.”和“..”，其内容除了文件", "score": 1.0 } ] }, { "bbox": [ 89, 629, 243, 641 ], "spans": [ { "bbox": [ 89, 629, 243, 641 ], "type": "text", "content": "名不同之外，其他字段完全相同。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 650, 250, 665 ], "type": "title", "angle": 0, "index": 23, "lines": [ { "bbox": [ 108, 650, 250, 666 ], "spans": [ { "bbox": [ 108, 650, 250, 666 ], "type": "text", "content": "4．更改当前目录函数 my_cd()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 678, 373, 762 ], "type": "list", "angle": 0, "index": 29, "blocks": [ { "bbox": [ 113, 678, 218, 692 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 114, 677, 217, 692 ], "spans": [ { "bbox": [ 114, 677, 217, 692 ], "type": "text", "content": "（1）对应命令：my_cd", "score": 1.0 } ] } ] }, { "bbox": [ 113, 696, 279, 709 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 114, 694, 280, 711 ], "spans": [ { "bbox": [ 114, 694, 280, 711 ], "type": "text", "content": "（2）命令调用格式：my_cd dirname", "score": 1.0 } ] } ] }, { "bbox": [ 113, 714, 341, 727 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 114, 712, 341, 729 ], "spans": [ { "bbox": [ 114, 712, 341, 729 ], "type": "text", "content": "（3）函数设计格式：void my_cd(char *dirname)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 732, 373, 745 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 114, 731, 374, 746 ], "spans": [ { "bbox": [ 114, 731, 374, 746 ], "type": "text", "content": "（4）功能：改变当前目录到指定的名为dirname 的目录。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 750, 162, 762 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 114, 749, 164, 765 ], "spans": [ { "bbox": [ 114, 749, 164, 765 ], "type": "text", "content": "（5）输入：", "score": 1.0 } ] } ] } ], "sub_type": "text" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 74 }, { "para_blocks": [ { "bbox": [ 133, 76, 293, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 135, 76, 295, 89 ], "spans": [ { "bbox": [ 135, 76, 295, 89 ], "type": "text", "content": "dirname：新的当前目录的目录名；", "score": 1.0 } ] } ] }, { "bbox": [ 113, 94, 180, 106 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 94, 180, 108 ], "spans": [ { "bbox": [ 114, 94, 180, 108 ], "type": "text", "content": "（6）输出：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 111, 226, 125 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 115, 111, 226, 126 ], "spans": [ { "bbox": [ 115, 111, 226, 126 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 130, 504, 286 ], "type": "list", "angle": 0, "index": 10, "blocks": [ { "bbox": [ 86, 130, 504, 160 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 130, 505, 143 ], "spans": [ { "bbox": [ 109, 130, 122, 142 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.83 }, { "bbox": [ 123, 131, 505, 143 ], "type": "text", "content": "调用my_open()打开指定目录名的父目录文件，并调用do_read()读入该父目录文件", "score": 1.0 } ] }, { "bbox": [ 89, 148, 158, 161 ], "spans": [ { "bbox": [ 89, 148, 158, 161 ], "type": "text", "content": "内容到内存中；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 165, 504, 196 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 109, 166, 504, 179 ], "spans": [ { "bbox": [ 109, 166, 122, 179 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.85 }, { "bbox": [ 123, 167, 408, 179 ], "type": "text", "content": "在父目录文件中检查新的当前目录名是否存在，如果存在则转", "score": 1.0 }, { "bbox": [ 409, 166, 421, 178 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.85 }, { "bbox": [ 421, 167, 504, 179 ], "type": "text", "content": "，否则返回，并显", "score": 1.0 } ] }, { "bbox": [ 88, 185, 146, 197 ], "spans": [ { "bbox": [ 88, 185, 146, 197 ], "type": "text", "content": "示出错信息；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 201, 333, 215 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 200, 334, 216 ], "spans": [ { "bbox": [ 109, 201, 122, 214 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.85 }, { "bbox": [ 122, 200, 222, 216 ], "type": "text", "content": "调用 my_close()关闭", "score": 1.0 }, { "bbox": [ 223, 202, 235, 215 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.86 }, { "bbox": [ 235, 200, 334, 216 ], "type": "text", "content": "中打开的父目录文件；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 220, 302, 232 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 220, 302, 233 ], "spans": [ { "bbox": [ 109, 220, 122, 232 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.85 }, { "bbox": [ 122, 221, 302, 233 ], "type": "text", "content": "调用my_close()关闭原当前目录文件；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 238, 504, 268 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 238, 505, 251 ], "spans": [ { "bbox": [ 109, 238, 122, 250 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.88 }, { "bbox": [ 122, 238, 505, 251 ], "type": "text", "content": "如果新的当前目录文件没有打开，则打开该目录文件；并将 ptrcurdir 指向该打开", "score": 1.0 } ] }, { "bbox": [ 88, 255, 138, 270 ], "spans": [ { "bbox": [ 88, 255, 138, 270 ], "type": "text", "content": "文件表项；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 274, 236, 286 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 274, 236, 286 ], "spans": [ { "bbox": [ 109, 274, 122, 286 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.84 }, { "bbox": [ 122, 275, 236, 286 ], "type": "text", "content": "设置当前目录为该目录。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 296, 255, 310 ], "type": "title", "angle": 0, "index": 11, "lines": [ { "bbox": [ 108, 294, 255, 312 ], "spans": [ { "bbox": [ 108, 294, 255, 312 ], "type": "text", "content": "5．创建子目录函数 my_mkdir()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 323, 362, 407 ], "type": "list", "angle": 0, "index": 17, "blocks": [ { "bbox": [ 113, 323, 232, 336 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 114, 322, 233, 338 ], "spans": [ { "bbox": [ 114, 322, 233, 338 ], "type": "text", "content": "（1）对应命令：my_mkdir", "score": 1.0 } ] } ] }, { "bbox": [ 113, 341, 301, 354 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 114, 340, 301, 355 ], "spans": [ { "bbox": [ 114, 340, 301, 355 ], "type": "text", "content": "（2）命令调用格式：my_ mkdir dirname", "score": 1.0 } ] } ] }, { "bbox": [ 113, 359, 356, 372 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 114, 359, 357, 374 ], "spans": [ { "bbox": [ 114, 359, 357, 374 ], "type": "text", "content": "（3）函数设计格式：void my_mkdir(char *dirname)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 377, 362, 390 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 376, 363, 391 ], "spans": [ { "bbox": [ 114, 376, 363, 391 ], "type": "text", "content": "（4）功能：在当前目录下创建名为 dirname 的子目录。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 395, 162, 407 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 394, 164, 410 ], "spans": [ { "bbox": [ 114, 394, 164, 410 ], "type": "text", "content": "（5）输入：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 134, 413, 273, 425 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 136, 413, 273, 426 ], "spans": [ { "bbox": [ 136, 413, 273, 426 ], "type": "text", "content": "dirname：新建目录的目录名。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 431, 184, 444 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 431, 185, 445 ], "spans": [ { "bbox": [ 114, 431, 185, 445 ], "type": "text", "content": "（6）输出：无。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 449, 225, 461 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 114, 449, 226, 462 ], "spans": [ { "bbox": [ 114, 449, 226, 462 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 466, 504, 714 ], "type": "list", "angle": 0, "index": 27, "blocks": [ { "bbox": [ 86, 466, 502, 497 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 109, 466, 502, 481 ], "spans": [ { "bbox": [ 109, 466, 122, 479 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.83 }, { "bbox": [ 123, 467, 502, 481 ], "type": "text", "content": "调用 do_read()读入当前目录文件内容到内存，检查当前目录下新建目录文件是否", "score": 1.0 } ] }, { "bbox": [ 89, 486, 273, 497 ], "spans": [ { "bbox": [ 89, 486, 273, 497 ], "type": "text", "content": "重名，若重名则返回，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 502, 504, 534 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 109, 502, 505, 516 ], "spans": [ { "bbox": [ 109, 502, 122, 516 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.83 }, { "bbox": [ 123, 503, 505, 516 ], "type": "text", "content": "为新建子目录文件分配一个空闲打开文件表项，如果没有空闲表项则返回-1，并显", "score": 1.0 } ] }, { "bbox": [ 88, 522, 147, 534 ], "spans": [ { "bbox": [ 88, 522, 147, 534 ], "type": "text", "content": "示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 539, 504, 570 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 109, 539, 504, 551 ], "spans": [ { "bbox": [ 109, 539, 122, 551 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.83 }, { "bbox": [ 122, 540, 482, 551 ], "type": "text", "content": "检查FAT是否有空闲的盘块，如有则为新建目录文件分配一个盘块，否则释放", "score": 1.0 }, { "bbox": [ 483, 539, 494, 551 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.87 }, { "bbox": [ 495, 540, 504, 551 ], "type": "text", "content": "中", "score": 1.0 } ] }, { "bbox": [ 88, 557, 305, 570 ], "spans": [ { "bbox": [ 88, 557, 305, 570 ], "type": "text", "content": "分配的打开文件表项，返回，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 575, 504, 623 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 109, 575, 499, 587 ], "spans": [ { "bbox": [ 109, 575, 122, 587 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.79 }, { "bbox": [ 123, 576, 499, 587 ], "type": "text", "content": "在当前目录中为新建目录文件寻找一个空闲的目录项或为其追加一个新的目录项;", "score": 1.0 } ] }, { "bbox": [ 89, 592, 505, 605 ], "spans": [ { "bbox": [ 89, 592, 505, 605 ], "type": "text", "content": "需修改当前目录文件的长度信息，并将当前目录文件的用户打开文件表项中的 fcbstate置", "score": 1.0 } ] }, { "bbox": [ 86, 610, 115, 625 ], "spans": [ { "bbox": [ 86, 610, 115, 625 ], "type": "text", "content": "为 1；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 629, 495, 660 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 109, 629, 494, 641 ], "spans": [ { "bbox": [ 109, 629, 122, 641 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.83 }, { "bbox": [ 122, 629, 494, 641 ], "type": "text", "content": "准备好新建目录文件的 FCB的内容，文件的属性为目录文件，以覆盖写方式调用", "score": 1.0 } ] }, { "bbox": [ 88, 647, 284, 660 ], "spans": [ { "bbox": [ 88, 647, 284, 660 ], "type": "text", "content": "do_write()将其填写到对应的空目录项中；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 664, 504, 714 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 109, 664, 504, 677 ], "spans": [ { "bbox": [ 109, 665, 122, 677 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.84 }, { "bbox": [ 123, 664, 504, 677 ], "type": "text", "content": "在新建目录文件所分配到的磁盘块中建立两个特殊的目录项“.”和“..”目录项，", "score": 1.0 } ] }, { "bbox": [ 88, 682, 502, 696 ], "spans": [ { "bbox": [ 88, 682, 502, 696 ], "type": "text", "content": "方法是：首先在用户空间中准备好内容，然后以截断写或者覆盖写方式调用do_write()将", "score": 1.0 } ] }, { "bbox": [ 88, 701, 231, 714 ], "spans": [ { "bbox": [ 88, 701, 120, 714 ], "type": "text", "content": "其写到", "score": 1.0 }, { "bbox": [ 120, 701, 132, 714 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.87 }, { "bbox": [ 132, 701, 231, 714 ], "type": "text", "content": "中分配到的磁盘块中；", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 719, 153, 731 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 109, 718, 154, 733 ], "spans": [ { "bbox": [ 109, 719, 122, 731 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.82 }, { "bbox": [ 122, 718, 154, 733 ], "type": "text", "content": "返回。", "score": 1.0 } ] } ] }, { "bbox": [ 107, 740, 239, 754 ], "type": "title", "angle": 0, "index": 29, "lines": [ { "bbox": [ 108, 739, 240, 756 ], "spans": [ { "bbox": [ 108, 739, 240, 756 ], "type": "text", "content": "6．删除子目录函数 rmdir()", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 75 }, { "para_blocks": [ { "bbox": [ 113, 76, 362, 160 ], "type": "list", "angle": 0, "index": 6, "blocks": [ { "bbox": [ 113, 76, 239, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 114, 74, 238, 91 ], "spans": [ { "bbox": [ 114, 74, 238, 91 ], "type": "text", "content": "（1）对应命令：my_ rmdir", "score": 1.0 } ] } ] }, { "bbox": [ 113, 95, 301, 107 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 93, 301, 109 ], "spans": [ { "bbox": [ 114, 93, 301, 109 ], "type": "text", "content": "（2）命令调用格式：my_ rmdir dirname", "score": 1.0 } ] } ] }, { "bbox": [ 113, 112, 357, 125 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 114, 112, 357, 126 ], "spans": [ { "bbox": [ 114, 112, 357, 126 ], "type": "text", "content": "（1）函数设计格式：void my_rmdir(char *dirname)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 130, 362, 142 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 115, 131, 363, 143 ], "spans": [ { "bbox": [ 115, 131, 363, 143 ], "type": "text", "content": "（2）功能：在当前目录下删除名为 dirname 的子目录。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 148, 163, 160 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 148, 163, 163 ], "spans": [ { "bbox": [ 114, 148, 163, 163 ], "type": "text", "content": "（3）输入：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 133, 166, 283, 179 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 135, 166, 285, 179 ], "spans": [ { "bbox": [ 135, 166, 285, 179 ], "type": "text", "content": "dirname：欲删除目录的目录名。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 184, 184, 196 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 114, 184, 185, 198 ], "spans": [ { "bbox": [ 114, 184, 185, 198 ], "type": "text", "content": "（4）输出：无。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 202, 226, 214 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 115, 202, 226, 215 ], "spans": [ { "bbox": [ 115, 202, 226, 215 ], "type": "text", "content": "（5）函数需完成的工作：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 220, 504, 395 ], "type": "list", "angle": 0, "index": 17, "blocks": [ { "bbox": [ 86, 220, 502, 250 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 220, 502, 233 ], "spans": [ { "bbox": [ 109, 220, 122, 232 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.83 }, { "bbox": [ 123, 221, 502, 233 ], "type": "text", "content": "调用do_read()读入当前目录文件内容到内存，检查当前目录下欲删除目录文件是", "score": 1.0 } ] }, { "bbox": [ 89, 238, 294, 251 ], "spans": [ { "bbox": [ 89, 238, 294, 251 ], "type": "text", "content": "否存在，若不存在则返回，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 255, 504, 286 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 109, 255, 505, 269 ], "spans": [ { "bbox": [ 109, 255, 122, 269 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.82 }, { "bbox": [ 123, 255, 505, 269 ], "type": "text", "content": "检查欲删除目录文件是否为空（除了“.”和“..”外没有其他子目录和文件），可", "score": 1.0 } ] }, { "bbox": [ 89, 275, 440, 286 ], "spans": [ { "bbox": [ 89, 275, 440, 286 ], "type": "text", "content": "根据其目录项中记录的文件长度来判断，若不为空则返回，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 291, 439, 306 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 291, 439, 306 ], "spans": [ { "bbox": [ 109, 291, 122, 304 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.86 }, { "bbox": [ 123, 291, 439, 306 ], "type": "text", "content": "检查该目录文件是否已经打开，若已打开则调用 my_close()关闭掉；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 310, 328, 322 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 310, 329, 323 ], "spans": [ { "bbox": [ 109, 310, 122, 322 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.85 }, { "bbox": [ 123, 310, 329, 323 ], "type": "text", "content": "回收该目录文件所占据的磁盘块，修改FAT；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 327, 504, 359 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 327, 505, 341 ], "spans": [ { "bbox": [ 109, 327, 122, 340 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.84 }, { "bbox": [ 122, 327, 505, 341 ], "type": "text", "content": "从当前目录文件中清空该目录文件的目录项，且 free字段置为0：以覆盖写方式调", "score": 1.0 } ] }, { "bbox": [ 88, 346, 192, 359 ], "spans": [ { "bbox": [ 88, 346, 192, 359 ], "type": "text", "content": "用 do_write()来实现；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 364, 503, 376 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 109, 364, 504, 376 ], "spans": [ { "bbox": [ 109, 364, 122, 376 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.84 }, { "bbox": [ 122, 364, 504, 376 ], "type": "text", "content": "修改当前目录文件的用户打开表项中的长度信息，并将表项中的 fcbstate 置为 1；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 381, 153, 395 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 109, 380, 154, 396 ], "spans": [ { "bbox": [ 109, 381, 122, 394 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.83 }, { "bbox": [ 122, 380, 154, 396 ], "type": "text", "content": "返回。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 108, 404, 229, 417 ], "type": "title", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 403, 229, 419 ], "spans": [ { "bbox": [ 109, 403, 229, 419 ], "type": "text", "content": "7．显示目录函数 my_ls()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 431, 373, 551 ], "type": "list", "angle": 0, "index": 26, "blocks": [ { "bbox": [ 113, 431, 217, 444 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 114, 429, 217, 446 ], "spans": [ { "bbox": [ 114, 429, 217, 446 ], "type": "text", "content": "（1）对应命令：my_ls", "score": 1.0 } ] } ] }, { "bbox": [ 113, 449, 238, 462 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 114, 447, 238, 464 ], "spans": [ { "bbox": [ 114, 447, 238, 464 ], "type": "text", "content": "（2）命令调用格式：my_ls", "score": 1.0 } ] } ] }, { "bbox": [ 113, 467, 293, 480 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 467, 294, 481 ], "spans": [ { "bbox": [ 114, 467, 294, 481 ], "type": "text", "content": "（3）函数设计格式：void my_ls(void)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 485, 373, 497 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 114, 485, 374, 498 ], "spans": [ { "bbox": [ 114, 485, 374, 498 ], "type": "text", "content": "（4）功能：显示当前目录的内容（子目录和文件信息）。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 503, 180, 515 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 114, 502, 180, 517 ], "spans": [ { "bbox": [ 114, 502, 180, 517 ], "type": "text", "content": "（5）输入：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 521, 180, 533 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 114, 520, 180, 535 ], "spans": [ { "bbox": [ 114, 520, 180, 535 ], "type": "text", "content": "（6）输出：无", "score": 1.0 } ] } ] }, { "bbox": [ 113, 539, 225, 551 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 114, 539, 226, 552 ], "spans": [ { "bbox": [ 114, 539, 226, 552 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 556, 382, 605 ], "type": "list", "angle": 0, "index": 30, "blocks": [ { "bbox": [ 107, 556, 339, 571 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 109, 556, 339, 571 ], "spans": [ { "bbox": [ 109, 556, 122, 570 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.85 }, { "bbox": [ 123, 556, 339, 571 ], "type": "text", "content": "调用 do_read()读出当前目录文件内容到内存；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 575, 382, 588 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 109, 575, 382, 587 ], "spans": [ { "bbox": [ 109, 575, 122, 587 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.85 }, { "bbox": [ 123, 576, 382, 587 ], "type": "text", "content": "将读出的目录文件的信息按照一定的格式显示到屏幕上；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 592, 153, 605 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 109, 592, 154, 607 ], "spans": [ { "bbox": [ 109, 592, 122, 605 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.86 }, { "bbox": [ 123, 592, 154, 607 ], "type": "text", "content": "返回。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 615, 250, 629 ], "type": "title", "angle": 0, "index": 31, "lines": [ { "bbox": [ 107, 613, 251, 631 ], "spans": [ { "bbox": [ 107, 613, 251, 631 ], "type": "text", "content": "8．创建文件函数 my_create()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 642, 367, 726 ], "type": "list", "angle": 0, "index": 37, "blocks": [ { "bbox": [ 113, 642, 238, 655 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 114, 640, 238, 657 ], "spans": [ { "bbox": [ 114, 640, 238, 657 ], "type": "text", "content": "（1）对应命令：my_create", "score": 1.0 } ] } ] }, { "bbox": [ 113, 660, 305, 672 ], "type": "text", "angle": 0, "index": 33, "lines": [ { "bbox": [ 114, 659, 307, 674 ], "spans": [ { "bbox": [ 114, 659, 307, 674 ], "type": "text", "content": "（2）命令调用格式：my_create filename", "score": 1.0 } ] } ] }, { "bbox": [ 113, 678, 367, 691 ], "type": "text", "angle": 0, "index": 34, "lines": [ { "bbox": [ 114, 677, 368, 692 ], "spans": [ { "bbox": [ 114, 677, 368, 692 ], "type": "text", "content": "（3）函数设计格式：int my_create (char *filename)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 696, 304, 708 ], "type": "text", "angle": 0, "index": 35, "lines": [ { "bbox": [ 114, 696, 305, 710 ], "spans": [ { "bbox": [ 114, 696, 305, 710 ], "type": "text", "content": "（4）功能：创建名为 filename 的新文件。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 714, 162, 726 ], "type": "text", "angle": 0, "index": 36, "lines": [ { "bbox": [ 114, 713, 164, 729 ], "spans": [ { "bbox": [ 114, 713, 164, 729 ], "type": "text", "content": "（5）输入：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 133, 732, 352, 745 ], "type": "text", "angle": 0, "index": 38, "lines": [ { "bbox": [ 135, 732, 353, 745 ], "spans": [ { "bbox": [ 135, 732, 353, 745 ], "type": "text", "content": "filename：新建文件的文件名，可能包含路径。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 750, 504, 762 ], "type": "text", "angle": 0, "index": 39, "lines": [ { "bbox": [ 115, 751, 505, 763 ], "spans": [ { "bbox": [ 115, 751, 505, 763 ], "type": "text", "content": "（6）输出：若创建成功，返回该文件的文件描述符（文件打开表中的数组下标）；否", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 76 }, { "para_blocks": [ { "bbox": [ 86, 76, 138, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 88, 76, 138, 89 ], "spans": [ { "bbox": [ 88, 76, 138, 89 ], "type": "text", "content": "则返回-1。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 94, 226, 107 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 94, 226, 107 ], "spans": [ { "bbox": [ 114, 94, 226, 107 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 111, 505, 412 ], "type": "list", "angle": 0, "index": 12, "blocks": [ { "bbox": [ 86, 111, 505, 142 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 109, 111, 505, 126 ], "spans": [ { "bbox": [ 109, 111, 122, 125 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.81 }, { "bbox": [ 123, 112, 505, 126 ], "type": "text", "content": "为新文件分配一个空闲打开文件表项，如果没有空闲表项则返回-1，并显示错误信", "score": 1.0 } ] }, { "bbox": [ 88, 129, 107, 145 ], "spans": [ { "bbox": [ 88, 129, 107, 145 ], "type": "text", "content": "息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 148, 503, 179 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 148, 502, 161 ], "spans": [ { "bbox": [ 109, 148, 122, 161 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.81 }, { "bbox": [ 123, 148, 502, 161 ], "type": "text", "content": "若新文件的父目录文件还没有打开，则调用 my_open()打开；若打开失败，则释放", "score": 1.0 } ] }, { "bbox": [ 88, 166, 410, 179 ], "spans": [ { "bbox": [ 88, 166, 101, 179 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.86 }, { "bbox": [ 101, 166, 410, 179 ], "type": "text", "content": "中为新建文件分配的空闲文件打开表项，返回-1，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 184, 502, 232 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 109, 184, 502, 196 ], "spans": [ { "bbox": [ 109, 184, 122, 196 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.83 }, { "bbox": [ 122, 184, 502, 196 ], "type": "text", "content": "调用do_read()读出该父目录文件内容到内存，检查该目录下新文件是否重名，若", "score": 1.0 } ] }, { "bbox": [ 89, 202, 502, 215 ], "spans": [ { "bbox": [ 89, 203, 141, 215 ], "type": "text", "content": "重名则释放", "score": 1.0 }, { "bbox": [ 141, 202, 153, 215 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.86 }, { "bbox": [ 154, 203, 374, 215 ], "type": "text", "content": "中分配的打开文件表项，并调用my_close()关闭", "score": 1.0 }, { "bbox": [ 375, 202, 387, 214 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.86 }, { "bbox": [ 387, 203, 502, 215 ], "type": "text", "content": "中打开的目录文件；然后", "score": 1.0 } ] }, { "bbox": [ 89, 220, 210, 232 ], "spans": [ { "bbox": [ 89, 220, 210, 232 ], "type": "text", "content": "返回-1，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 238, 504, 269 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 109, 238, 504, 250 ], "spans": [ { "bbox": [ 109, 238, 122, 250 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.81 }, { "bbox": [ 122, 239, 451, 250 ], "type": "text", "content": "检查FAT是否有空闲的盘块，如有则为新文件分配一个盘块，否则释放", "score": 1.0 }, { "bbox": [ 451, 238, 463, 250 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.87 }, { "bbox": [ 463, 239, 504, 250 ], "type": "text", "content": "中分配的", "score": 1.0 } ] }, { "bbox": [ 89, 256, 496, 269 ], "spans": [ { "bbox": [ 89, 257, 269, 269 ], "type": "text", "content": "打开文件表项，并调用 my_close()关闭", "score": 1.0 }, { "bbox": [ 270, 256, 282, 269 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.87 }, { "bbox": [ 282, 257, 496, 269 ], "type": "text", "content": "中打开的目录文件；返回-1，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 274, 500, 305 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 109, 274, 499, 286 ], "spans": [ { "bbox": [ 109, 274, 122, 286 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.85 }, { "bbox": [ 123, 275, 499, 286 ], "type": "text", "content": "在父目录中为新文件寻找一个空闲的目录项或为其追加一个新的目录项;需修改该", "score": 1.0 } ] }, { "bbox": [ 90, 293, 464, 305 ], "spans": [ { "bbox": [ 90, 293, 464, 305 ], "type": "text", "content": "目录文件的长度信息，并将该目录文件的用户打开文件表项中的fcbstate置为 1；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 310, 502, 341 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 109, 310, 501, 322 ], "spans": [ { "bbox": [ 109, 310, 122, 322 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.83 }, { "bbox": [ 122, 311, 501, 322 ], "type": "text", "content": "准备好新文件的FCB的内容，文件的属性为数据文件，长度为0，以覆盖写方式调", "score": 1.0 } ] }, { "bbox": [ 88, 327, 327, 340 ], "spans": [ { "bbox": [ 88, 327, 207, 340 ], "type": "text", "content": "用 do_write()将其填写到", "score": 1.0 }, { "bbox": [ 207, 327, 218, 340 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.87 }, { "bbox": [ 219, 327, 327, 340 ], "type": "text", "content": "中分配到的空目录项中；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 345, 504, 376 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 109, 345, 504, 359 ], "spans": [ { "bbox": [ 109, 345, 122, 359 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.85 }, { "bbox": [ 122, 345, 188, 359 ], "type": "text", "content": "为新文件填写", "score": 1.0 }, { "bbox": [ 188, 346, 200, 358 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.87 }, { "bbox": [ 201, 345, 504, 359 ], "type": "text", "content": "中分配到的空闲打开文件表项，fcbstate字段值为0，读写指针值", "score": 1.0 } ] }, { "bbox": [ 86, 363, 115, 379 ], "spans": [ { "bbox": [ 86, 363, 115, 379 ], "type": "text", "content": "为 0；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 381, 333, 395 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 109, 381, 334, 396 ], "spans": [ { "bbox": [ 109, 381, 122, 394 ], "type": "inline_equation", "content": "\\textcircled{8}", "score": 0.85 }, { "bbox": [ 122, 381, 222, 396 ], "type": "text", "content": "调用 my_close()关闭", "score": 1.0 }, { "bbox": [ 223, 381, 235, 394 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.85 }, { "bbox": [ 235, 381, 334, 396 ], "type": "text", "content": "中打开的父目录文件；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 399, 373, 412 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 109, 399, 374, 413 ], "spans": [ { "bbox": [ 109, 400, 122, 412 ], "type": "inline_equation", "content": "\\textcircled{9}", "score": 0.83 }, { "bbox": [ 122, 399, 374, 413 ], "type": "text", "content": "将新文件的打开文件表项序号作为其文件描述符返回。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 422, 229, 435 ], "type": "title", "angle": 0, "index": 13, "lines": [ { "bbox": [ 107, 419, 229, 438 ], "spans": [ { "bbox": [ 107, 419, 229, 438 ], "type": "text", "content": "9．删除文件函数 my_rm()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 449, 346, 533 ], "type": "list", "angle": 0, "index": 19, "blocks": [ { "bbox": [ 113, 449, 217, 462 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 114, 448, 217, 464 ], "spans": [ { "bbox": [ 114, 448, 217, 464 ], "type": "text", "content": "（1）对应命令：my_rm", "score": 1.0 } ] } ] }, { "bbox": [ 113, 467, 285, 480 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 114, 465, 286, 481 ], "spans": [ { "bbox": [ 114, 465, 286, 481 ], "type": "text", "content": "（2）命令调用格式：my_rm filename", "score": 1.0 } ] } ] }, { "bbox": [ 113, 485, 346, 498 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 114, 483, 346, 500 ], "spans": [ { "bbox": [ 114, 483, 346, 500 ], "type": "text", "content": "（3）函数设计格式：void my_rm(char *filename)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 503, 293, 515 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 114, 502, 295, 517 ], "spans": [ { "bbox": [ 114, 502, 295, 517 ], "type": "text", "content": "（4）功能：删除名为 filename 的文件。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 521, 162, 533 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 114, 519, 164, 535 ], "spans": [ { "bbox": [ 114, 519, 164, 535 ], "type": "text", "content": "（5）输入：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 133, 539, 373, 551 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 135, 539, 374, 553 ], "spans": [ { "bbox": [ 135, 539, 374, 553 ], "type": "text", "content": "filename：欲删除文件的文件名，可能还包含路径。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 557, 184, 569 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 556, 185, 571 ], "spans": [ { "bbox": [ 114, 556, 185, 571 ], "type": "text", "content": "（6）输出：无。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 575, 226, 587 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 115, 575, 226, 588 ], "spans": [ { "bbox": [ 115, 575, 226, 588 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 592, 504, 767 ], "type": "list", "angle": 0, "index": 29, "blocks": [ { "bbox": [ 86, 592, 502, 624 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 109, 592, 502, 606 ], "spans": [ { "bbox": [ 109, 592, 122, 605 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.84 }, { "bbox": [ 123, 593, 502, 606 ], "type": "text", "content": "若欲删除文件的父目录文件还没有打开，则调用my_open()打开；若打开失败，则", "score": 1.0 } ] }, { "bbox": [ 88, 611, 200, 624 ], "spans": [ { "bbox": [ 88, 611, 200, 624 ], "type": "text", "content": "返回，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 629, 503, 660 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 109, 629, 504, 641 ], "spans": [ { "bbox": [ 109, 629, 122, 641 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.85 }, { "bbox": [ 123, 629, 504, 641 ], "type": "text", "content": "调用do_read()读出该父目录文件内容到内存，检查该目录下欲删除文件是否存在，", "score": 1.0 } ] }, { "bbox": [ 89, 648, 252, 660 ], "spans": [ { "bbox": [ 89, 648, 252, 660 ], "type": "text", "content": "若不存在则返回，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 665, 341, 678 ], "type": "text", "angle": 0, "index": 25, "lines": [ { "bbox": [ 109, 665, 342, 678 ], "spans": [ { "bbox": [ 109, 665, 122, 677 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.85 }, { "bbox": [ 123, 665, 342, 678 ], "type": "text", "content": "检查该文件是否已经打开，若已打开则关闭掉；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 682, 307, 696 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 109, 682, 307, 696 ], "spans": [ { "bbox": [ 109, 682, 122, 695 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.86 }, { "bbox": [ 123, 682, 307, 696 ], "type": "text", "content": "回收该文件所占据的磁盘块，修改FAT；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 700, 504, 732 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 109, 700, 505, 714 ], "spans": [ { "bbox": [ 109, 700, 122, 714 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.87 }, { "bbox": [ 122, 701, 505, 714 ], "type": "text", "content": "从文件的父目录文件中清空该文件的目录项，且 free字段置为0：以覆盖写方式调", "score": 1.0 } ] }, { "bbox": [ 89, 719, 202, 731 ], "spans": [ { "bbox": [ 89, 719, 202, 731 ], "type": "text", "content": "用 do_write()来实现；；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 736, 497, 767 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 109, 736, 498, 750 ], "spans": [ { "bbox": [ 109, 736, 122, 749 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.87 }, { "bbox": [ 122, 737, 498, 750 ], "type": "text", "content": "修改该父目录文件的用户打开文件表项中的长度信息，并将该表项中的 fcbstate", "score": 1.0 } ] }, { "bbox": [ 88, 752, 124, 771 ], "spans": [ { "bbox": [ 88, 752, 124, 771 ], "type": "text", "content": "置为 1；", "score": 1.0 } ] } ] } ], "sub_type": "text" } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 77 }, { "para_blocks": [ { "bbox": [ 110, 76, 151, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 109, 74, 155, 91 ], "spans": [ { "bbox": [ 109, 76, 122, 89 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.77 }, { "bbox": [ 123, 74, 155, 91 ], "type": "text", "content": "返回。", "score": 1.0 } ] } ] }, { "bbox": [ 110, 98, 243, 112 ], "type": "title", "angle": 0, "index": 2, "lines": [ { "bbox": [ 108, 96, 245, 115 ], "spans": [ { "bbox": [ 108, 96, 245, 115 ], "type": "text", "content": "10．打开文件函数 my_open()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 125, 351, 208 ], "type": "list", "angle": 0, "index": 8, "blocks": [ { "bbox": [ 113, 125, 227, 137 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 114, 124, 228, 140 ], "spans": [ { "bbox": [ 114, 124, 228, 140 ], "type": "text", "content": "（1）对应命令：my_open", "score": 1.0 } ] } ] }, { "bbox": [ 113, 143, 295, 155 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 114, 142, 296, 158 ], "spans": [ { "bbox": [ 114, 142, 296, 158 ], "type": "text", "content": "（2）命令调用格式：my_open filename", "score": 1.0 } ] } ] }, { "bbox": [ 113, 161, 351, 173 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 114, 160, 352, 175 ], "spans": [ { "bbox": [ 114, 160, 352, 175 ], "type": "text", "content": "（3）函数设计格式：int my_open(char *filename)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 179, 346, 190 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 115, 179, 347, 192 ], "spans": [ { "bbox": [ 115, 179, 347, 192 ], "type": "text", "content": "（4）功能：打开当前目录下名为 filename的文件。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 197, 162, 208 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 195, 164, 211 ], "spans": [ { "bbox": [ 114, 195, 164, 211 ], "type": "text", "content": "（5）输入：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 134, 215, 284, 227 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 135, 215, 284, 228 ], "spans": [ { "bbox": [ 135, 215, 284, 228 ], "type": "text", "content": "filename：欲打开文件的文件名", "score": 1.0 } ] } ] }, { "bbox": [ 86, 232, 504, 281 ], "type": "list", "angle": 0, "index": 12, "blocks": [ { "bbox": [ 86, 232, 504, 263 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 115, 232, 505, 246 ], "spans": [ { "bbox": [ 115, 232, 505, 246 ], "type": "text", "content": "（6）输出：若打开成功，返回该文件的描述符（在用户打开文件表中表项序号）；否", "score": 1.0 } ] }, { "bbox": [ 88, 251, 138, 264 ], "spans": [ { "bbox": [ 88, 251, 138, 264 ], "type": "text", "content": "则返回-1。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 269, 224, 281 ], "type": "text", "angle": 0, "index": 11, "lines": [ { "bbox": [ 114, 269, 226, 282 ], "spans": [ { "bbox": [ 114, 269, 226, 282 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 287, 504, 424 ], "type": "list", "angle": 0, "index": 18, "blocks": [ { "bbox": [ 107, 287, 424, 299 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 287, 426, 301 ], "spans": [ { "bbox": [ 109, 287, 122, 300 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.85 }, { "bbox": [ 123, 287, 426, 301 ], "type": "text", "content": "检查该文件是否已经打开，若已打开则返回-1，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 305, 503, 335 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 305, 505, 318 ], "spans": [ { "bbox": [ 109, 305, 122, 317 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.85 }, { "bbox": [ 122, 306, 505, 318 ], "type": "text", "content": "调用do_read()读出父目录文件的内容到内存，检查该目录下欲打开文件是否存在，", "score": 1.0 } ] }, { "bbox": [ 89, 324, 262, 335 ], "spans": [ { "bbox": [ 89, 324, 262, 335 ], "type": "text", "content": "若不存在则返回-1，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 341, 504, 371 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 109, 341, 505, 354 ], "spans": [ { "bbox": [ 109, 341, 122, 354 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.87 }, { "bbox": [ 122, 342, 505, 354 ], "type": "text", "content": "检查用户打开文件表中是否有空表项，若有则为欲打开文件分配一个空表项，若没", "score": 1.0 } ] }, { "bbox": [ 88, 359, 232, 372 ], "spans": [ { "bbox": [ 88, 359, 232, 372 ], "type": "text", "content": "有则返回-1，并显示错误信息；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 376, 411, 389 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 109, 376, 412, 391 ], "spans": [ { "bbox": [ 109, 376, 122, 389 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.84 }, { "bbox": [ 123, 377, 412, 391 ], "type": "text", "content": "为该文件填写空白用户打开文件表表项内容，读写指针置为 0；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 395, 504, 424 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 395, 506, 407 ], "spans": [ { "bbox": [ 109, 395, 122, 407 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.86 }, { "bbox": [ 122, 395, 506, 407 ], "type": "text", "content": "将该文件所分配到的空白用户打开文件表表项序号（数组下标）作为文件描述符 fd", "score": 1.0 } ] }, { "bbox": [ 108, 412, 139, 428 ], "spans": [ { "bbox": [ 108, 412, 139, 428 ], "type": "text", "content": "返回。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 110, 435, 249, 449 ], "type": "title", "angle": 0, "index": 19, "lines": [ { "bbox": [ 108, 433, 251, 451 ], "spans": [ { "bbox": [ 108, 433, 251, 451 ], "type": "text", "content": "11．关闭文件函数 my_close()", "score": 1.0 } ] } ] }, { "bbox": [ 113, 462, 417, 545 ], "type": "list", "angle": 0, "index": 25, "blocks": [ { "bbox": [ 113, 462, 232, 475 ], "type": "text", "angle": 0, "index": 20, "lines": [ { "bbox": [ 114, 460, 233, 477 ], "spans": [ { "bbox": [ 114, 460, 233, 477 ], "type": "text", "content": "（1）对应命令：my_close", "score": 1.0 } ] } ] }, { "bbox": [ 113, 480, 268, 492 ], "type": "text", "angle": 0, "index": 21, "lines": [ { "bbox": [ 114, 479, 270, 494 ], "spans": [ { "bbox": [ 114, 479, 270, 494 ], "type": "text", "content": "（2）命令调用格式：my_close fd", "score": 1.0 } ] } ] }, { "bbox": [ 113, 498, 320, 510 ], "type": "text", "angle": 0, "index": 22, "lines": [ { "bbox": [ 114, 497, 320, 512 ], "spans": [ { "bbox": [ 114, 497, 320, 512 ], "type": "text", "content": "（3）函数设计格式：void my_close(int fd)", "score": 1.0 } ] } ] }, { "bbox": [ 113, 516, 417, 528 ], "type": "text", "angle": 0, "index": 23, "lines": [ { "bbox": [ 114, 516, 418, 530 ], "spans": [ { "bbox": [ 114, 516, 418, 530 ], "type": "text", "content": "（4）功能：关闭前面由 my_open()打开的文件描述符为 fd 的文件。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 534, 162, 545 ], "type": "text", "angle": 0, "index": 24, "lines": [ { "bbox": [ 114, 533, 164, 548 ], "spans": [ { "bbox": [ 114, 533, 164, 548 ], "type": "text", "content": "（5）输入：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 134, 552, 214, 564 ], "type": "text", "angle": 0, "index": 26, "lines": [ { "bbox": [ 136, 552, 216, 565 ], "spans": [ { "bbox": [ 136, 552, 216, 565 ], "type": "text", "content": "fd：文件描述符。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 570, 183, 581 ], "type": "text", "angle": 0, "index": 27, "lines": [ { "bbox": [ 114, 570, 185, 583 ], "spans": [ { "bbox": [ 114, 570, 185, 583 ], "type": "text", "content": "（6）输出：无。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 587, 225, 600 ], "type": "text", "angle": 0, "index": 28, "lines": [ { "bbox": [ 114, 587, 226, 601 ], "spans": [ { "bbox": [ 114, 587, 226, 601 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 605, 504, 744 ], "type": "list", "angle": 0, "index": 33, "blocks": [ { "bbox": [ 86, 605, 502, 636 ], "type": "text", "angle": 0, "index": 29, "lines": [ { "bbox": [ 109, 605, 502, 619 ], "spans": [ { "bbox": [ 109, 605, 122, 618 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.83 }, { "bbox": [ 122, 606, 502, 619 ], "type": "text", "content": "检查fd的有效性（fd不能超出用户打开文件表所在数组的最大下标），如果无效", "score": 1.0 } ] }, { "bbox": [ 88, 624, 138, 638 ], "spans": [ { "bbox": [ 88, 624, 138, 638 ], "type": "text", "content": "则返回-1；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 642, 504, 690 ], "type": "text", "angle": 0, "index": 30, "lines": [ { "bbox": [ 109, 642, 505, 655 ], "spans": [ { "bbox": [ 109, 642, 122, 655 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.82 }, { "bbox": [ 123, 643, 505, 654 ], "type": "text", "content": "检查用户打开文件表表项中的 fcbstate字段的值，如果为1则需要将该文件的 FCB", "score": 1.0 } ] }, { "bbox": [ 89, 661, 505, 672 ], "spans": [ { "bbox": [ 89, 661, 505, 672 ], "type": "text", "content": "的内容保存到虚拟磁盘上该文件的目录项中，方法是：打开该文件的父目录文件，以覆盖写", "score": 1.0 } ] }, { "bbox": [ 89, 678, 423, 691 ], "spans": [ { "bbox": [ 89, 678, 423, 691 ], "type": "text", "content": "方式调用do_write()将欲关闭文件的 FCB写入父目录文件的相应盘块中；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 696, 503, 725 ], "type": "text", "angle": 0, "index": 31, "lines": [ { "bbox": [ 109, 696, 505, 710 ], "spans": [ { "bbox": [ 109, 696, 122, 708 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.83 }, { "bbox": [ 122, 696, 505, 710 ], "type": "text", "content": "回收该文件占据的用户打开文件表表项（进行清空操作），并将 topenfile 字段置", "score": 1.0 } ] }, { "bbox": [ 86, 711, 116, 730 ], "spans": [ { "bbox": [ 86, 711, 116, 730 ], "type": "text", "content": "为 0；", "score": 1.0 } ] } ] }, { "bbox": [ 108, 732, 151, 744 ], "type": "text", "angle": 0, "index": 32, "lines": [ { "bbox": [ 109, 731, 154, 746 ], "spans": [ { "bbox": [ 109, 731, 122, 744 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.74 }, { "bbox": [ 122, 731, 154, 746 ], "type": "text", "content": "返回。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 110, 754, 239, 767 ], "type": "title", "angle": 0, "index": 34, "lines": [ { "bbox": [ 108, 751, 240, 770 ], "spans": [ { "bbox": [ 108, 751, 240, 770 ], "type": "text", "content": "12．写文件函数 my_write()", "score": 1.0 } ] } ] } ], "discarded_blocks": [ { "bbox": [ 223, 42, 370, 53 ], "type": "header", "angle": 0, "index": 0, "lines": [ { "bbox": [ 224, 42, 370, 53 ], "spans": [ { "bbox": [ 224, 42, 370, 53 ], "type": "text", "content": "版权归杭州电子科技大学计算机学院", "score": 1.0 } ] } ] } ], "page_size": [ 595, 841 ], "page_idx": 78 }, { "para_blocks": [ { "bbox": [ 86, 76, 505, 232 ], "type": "list", "angle": 0, "index": 5, "blocks": [ { "bbox": [ 113, 76, 233, 89 ], "type": "text", "angle": 0, "index": 1, "lines": [ { "bbox": [ 114, 74, 233, 91 ], "spans": [ { "bbox": [ 114, 74, 233, 91 ], "type": "text", "content": "（1）对应命令：my_write", "score": 1.0 } ] } ] }, { "bbox": [ 113, 95, 271, 107 ], "type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 114, 92, 270, 109 ], "spans": [ { "bbox": [ 114, 92, 270, 109 ], "type": "text", "content": "（2）命令调用格式：my_write fd", "score": 1.0 } ] } ] }, { "bbox": [ 113, 112, 315, 126 ], "type": "text", "angle": 0, "index": 3, "lines": [ { "bbox": [ 114, 111, 315, 126 ], "spans": [ { "bbox": [ 114, 111, 315, 126 ], "type": "text", "content": "（3）函数设计格式：int my_write(int fd)", "score": 1.0 } ] } ] }, { "bbox": [ 86, 130, 505, 232 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 114, 131, 505, 142 ], "spans": [ { "bbox": [ 114, 131, 505, 142 ], "type": "text", "content": "（4）功能：将用户通过键盘输入的内容写到 fd 所指定的文件中。磁盘文件的读写操作", "score": 1.0 } ] }, { "bbox": [ 89, 148, 505, 160 ], "spans": [ { "bbox": [ 89, 148, 505, 160 ], "type": "text", "content": "都必须以完整的数据块为单位进行，在写操作时，先将数据写在缓冲区中，缓冲区的大小与", "score": 1.0 } ] }, { "bbox": [ 89, 166, 505, 179 ], "spans": [ { "bbox": [ 89, 166, 505, 179 ], "type": "text", "content": "磁盘块的大小相同，然后再将缓冲区中的数据一次性写到磁盘块中；读出时先将一个磁盘块", "score": 1.0 } ] }, { "bbox": [ 89, 185, 499, 197 ], "spans": [ { "bbox": [ 89, 185, 499, 197 ], "type": "text", "content": "中的内容读到缓冲区中，然后再传送到用户区。本实例为了简便起见，没有设置缓冲区管理，", "score": 1.0 } ] }, { "bbox": [ 89, 203, 492, 215 ], "spans": [ { "bbox": [ 89, 203, 492, 215 ], "type": "text", "content": "只是在读写文件时由用户使用 malloc()申请一块空间作为缓冲区，读写操作结束后使用", "score": 1.0 } ] }, { "bbox": [ 88, 221, 158, 232 ], "spans": [ { "bbox": [ 88, 221, 158, 232 ], "type": "text", "content": "free()释放掉。", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 238, 506, 322 ], "type": "text", "angle": 0, "index": 6, "lines": [ { "bbox": [ 110, 238, 505, 250 ], "spans": [ { "bbox": [ 110, 238, 505, 250 ], "type": "text", "content": "写操作常有三种方式：截断写、覆盖写和追加写。截断写是放弃原来文件的内容，重新", "score": 1.0 } ] }, { "bbox": [ 89, 257, 505, 269 ], "spans": [ { "bbox": [ 89, 257, 505, 269 ], "type": "text", "content": "写文件；覆盖写是修改文件在当前读写指针所指的位置开始的部分内容；追加写是在原文件", "score": 1.0 } ] }, { "bbox": [ 89, 275, 505, 286 ], "spans": [ { "bbox": [ 89, 275, 505, 286 ], "type": "text", "content": "的最后添加新的内容。在本实例中，输入写文件命令后，系统会出现提示让用户选择其中的", "score": 1.0 } ] }, { "bbox": [ 89, 292, 489, 305 ], "spans": [ { "bbox": [ 89, 292, 489, 305 ], "type": "text", "content": "一种写方式，并将随后键盘输入的内容按照所选的方式写到文件中，键盘输入内容通过", "score": 1.0 } ] }, { "bbox": [ 88, 310, 251, 322 ], "spans": [ { "bbox": [ 88, 310, 117, 322 ], "type": "inline_equation", "content": "\\mathrm { C T R } { + } Z", "score": 0.7 }, { "bbox": [ 117, 311, 251, 322 ], "type": "text", "content": "键（或其他设定的键）结束。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 327, 162, 340 ], "type": "text", "angle": 0, "index": 7, "lines": [ { "bbox": [ 114, 327, 164, 343 ], "spans": [ { "bbox": [ 114, 327, 164, 343 ], "type": "text", "content": "（5）输入：", "score": 1.0 } ] } ] }, { "bbox": [ 134, 346, 340, 359 ], "type": "text", "angle": 0, "index": 8, "lines": [ { "bbox": [ 134, 344, 342, 361 ], "spans": [ { "bbox": [ 134, 344, 342, 361 ], "type": "text", "content": "fd： open()函数的返回值，文件的描述符；", "score": 1.0 } ] } ] }, { "bbox": [ 113, 364, 257, 395 ], "type": "list", "angle": 0, "index": 11, "blocks": [ { "bbox": [ 113, 364, 257, 376 ], "type": "text", "angle": 0, "index": 9, "lines": [ { "bbox": [ 115, 364, 258, 377 ], "spans": [ { "bbox": [ 115, 364, 258, 377 ], "type": "text", "content": "（6）输出：实际写入的字节数。", "score": 1.0 } ] } ] }, { "bbox": [ 113, 382, 226, 395 ], "type": "text", "angle": 0, "index": 10, "lines": [ { "bbox": [ 116, 382, 226, 394 ], "spans": [ { "bbox": [ 116, 382, 226, 394 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 86, 400, 505, 719 ], "type": "list", "angle": 0, "index": 21, "blocks": [ { "bbox": [ 86, 400, 502, 431 ], "type": "text", "angle": 0, "index": 12, "lines": [ { "bbox": [ 109, 399, 502, 412 ], "spans": [ { "bbox": [ 109, 399, 122, 412 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.84 }, { "bbox": [ 123, 401, 502, 412 ], "type": "text", "content": "检查fd的有效性（fd不能超出用户打开文件表所在数组的最大下标），如果无效", "score": 1.0 } ] }, { "bbox": [ 89, 417, 221, 431 ], "spans": [ { "bbox": [ 89, 417, 221, 431 ], "type": "text", "content": "则返回-1，并显示出错信息；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 436, 442, 449 ], "type": "text", "angle": 0, "index": 13, "lines": [ { "bbox": [ 109, 435, 442, 449 ], "spans": [ { "bbox": [ 109, 435, 122, 449 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.83 }, { "bbox": [ 123, 435, 442, 449 ], "type": "text", "content": "提示并等待用户输入写方式：（1：截断写；2：覆盖写；3：追加写）", "score": 1.0 } ] } ] }, { "bbox": [ 86, 454, 505, 521 ], "type": "text", "angle": 0, "index": 14, "lines": [ { "bbox": [ 109, 454, 505, 466 ], "spans": [ { "bbox": [ 109, 454, 122, 466 ], "type": "inline_equation", "content": "\\textcircled{3}", "score": 0.84 }, { "bbox": [ 123, 454, 505, 466 ], "type": "text", "content": "如果用户要求的写方式是截断写，则释放文件除第一块外的其他磁盘空间内容（查", "score": 1.0 } ] }, { "bbox": [ 89, 472, 505, 484 ], "spans": [ { "bbox": [ 89, 472, 505, 484 ], "type": "text", "content": "找并修改FAT表），将内存用户打开文件表项中文件长度修改为 0，将读写指针置为 0 并转", "score": 1.0 } ] }, { "bbox": [ 88, 489, 505, 502 ], "spans": [ { "bbox": [ 88, 489, 101, 502 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.85 }, { "bbox": [ 101, 491, 505, 502 ], "type": "text", "content": "；如果用户要求的写方式是追加写，则修改文件的当前读写指针位置到文件的末尾，并转", "score": 1.0 } ] }, { "bbox": [ 88, 507, 273, 520 ], "spans": [ { "bbox": [ 88, 507, 100, 520 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.85 }, { "bbox": [ 101, 508, 257, 520 ], "type": "text", "content": "；如果写方式是覆盖写，则直接转", "score": 1.0 }, { "bbox": [ 257, 507, 268, 520 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.88 }, { "bbox": [ 269, 508, 273, 520 ], "type": "text", "content": "；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 525, 505, 556 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 109, 525, 505, 539 ], "spans": [ { "bbox": [ 109, 525, 122, 538 ], "type": "inline_equation", "content": "\\textcircled{4}", "score": 0.82 }, { "bbox": [ 123, 526, 264, 539 ], "type": "text", "content": "提示用户：整个输入内容通过", "score": 1.0 }, { "bbox": [ 264, 526, 293, 538 ], "type": "inline_equation", "content": "\\mathrm { C T R } { + } Z", "score": 0.77 }, { "bbox": [ 293, 526, 505, 539 ], "type": "text", "content": "键（或其他设定的键）结束；用户可分多次输", "score": 1.0 } ] }, { "bbox": [ 89, 544, 231, 557 ], "spans": [ { "bbox": [ 89, 544, 231, 557 ], "type": "text", "content": "入写入内容，每次用回车结束；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 561, 504, 592 ], "type": "text", "angle": 0, "index": 16, "lines": [ { "bbox": [ 109, 560, 505, 575 ], "spans": [ { "bbox": [ 109, 561, 122, 574 ], "type": "inline_equation", "content": "\\textcircled{5}", "score": 0.84 }, { "bbox": [ 123, 560, 505, 575 ], "type": "text", "content": "等待用户从键盘输入文件内容，并将用户的本次输入内容保存到一临时变量 text[]", "score": 1.0 } ] }, { "bbox": [ 89, 580, 431, 592 ], "spans": [ { "bbox": [ 89, 580, 290, 592 ], "type": "text", "content": "中，要求每次输入以回车结束，全部结束用", "score": 1.0 }, { "bbox": [ 290, 580, 319, 592 ], "type": "inline_equation", "content": "\\mathrm { C T R } { + } Z", "score": 0.83 }, { "bbox": [ 319, 580, 431, 592 ], "type": "text", "content": "键（或其他设定的键）；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 597, 386, 611 ], "type": "text", "angle": 0, "index": 17, "lines": [ { "bbox": [ 109, 597, 386, 611 ], "spans": [ { "bbox": [ 109, 597, 122, 610 ], "type": "inline_equation", "content": "\\textcircled{6}", "score": 0.86 }, { "bbox": [ 122, 597, 386, 611 ], "type": "text", "content": "调用do_write()函数将通过键盘键入的内容写到文件中。", "score": 1.0 } ] } ] }, { "bbox": [ 86, 615, 505, 646 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 615, 505, 628 ], "spans": [ { "bbox": [ 109, 615, 122, 628 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.86 }, { "bbox": [ 123, 617, 505, 628 ], "type": "text", "content": "如果do_write()函数的返回值为非负值，则将实际写入字节数增加do_write()函数", "score": 1.0 } ] }, { "bbox": [ 89, 634, 262, 645 ], "spans": [ { "bbox": [ 89, 634, 246, 645 ], "type": "text", "content": "返回值，否则显示出错信息，并转", "score": 1.0 }, { "bbox": [ 246, 634, 258, 645 ], "type": "inline_equation", "content": "\\textcircled{9}", "score": 0.85 }, { "bbox": [ 258, 634, 262, 645 ], "type": "text", "content": "；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 651, 504, 682 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 651, 505, 665 ], "spans": [ { "bbox": [ 109, 651, 122, 664 ], "type": "inline_equation", "content": "\\textcircled{8}", "score": 0.83 }, { "bbox": [ 122, 652, 318, 665 ], "type": "text", "content": "如果text[]中最后一个字符不是结束字符", "score": 1.0 }, { "bbox": [ 319, 652, 348, 664 ], "type": "inline_equation", "content": "\\mathrm { C T R } { + } Z", "score": 0.84 }, { "bbox": [ 348, 652, 377, 665 ], "type": "text", "content": "，则转", "score": 1.0 }, { "bbox": [ 377, 651, 389, 664 ], "type": "inline_equation", "content": "\\textcircled{7}", "score": 0.84 }, { "bbox": [ 389, 652, 505, 665 ], "type": "text", "content": "继续进行写操作；否则转", "score": 1.0 } ] }, { "bbox": [ 88, 667, 106, 684 ], "spans": [ { "bbox": [ 88, 669, 101, 682 ], "type": "inline_equation", "content": "\\textcircled{9}", "score": 0.79 }, { "bbox": [ 101, 667, 106, 684 ], "type": "text", "content": "；", "score": 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"lines": [ { "bbox": [ 109, 327, 501, 340 ], "spans": [ { "bbox": [ 109, 327, 122, 340 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.82 }, { "bbox": [ 123, 328, 501, 340 ], "type": "text", "content": "将读写指针转化为逻辑块块号和块内偏移 off，并利用打开文件表表项中的首块号", "score": 1.0 } ] }, { "bbox": [ 89, 347, 505, 359 ], "spans": [ { "bbox": [ 89, 347, 505, 359 ], "type": "text", "content": "及FAT表的相关内容将逻辑块块号转换成对应的磁盘块块号 blkno；如果找不到对应的磁盘", "score": 1.0 } ] }, { "bbox": [ 88, 364, 500, 377 ], "spans": [ { "bbox": [ 88, 364, 500, 377 ], "type": "text", "content": "块，则需要检索FAT为该逻辑块分配一新的磁盘块，并将对应的磁盘块块号blkno登记到", "score": 1.0 } ] }, { "bbox": [ 88, 381, 323, 394 ], "spans": [ { "bbox": [ 88, 381, 323, 394 ], "type": "text", "content": "FAT中，若分配失败，则返回-1，并显示出错信息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 400, 502, 431 ], "type": "text", "angle": 0, "index": 15, "lines": [ { "bbox": [ 109, 399, 501, 412 ], "spans": [ { "bbox": [ 109, 399, 122, 412 ], "type": "inline_equation", "content": 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"index": 17, "lines": [ { "bbox": [ 114, 395, 226, 408 ], "spans": [ { "bbox": [ 114, 395, 226, 408 ], "type": "text", "content": "（7）函数需完成的工作：", "score": 1.0 } ] } ] }, { "bbox": [ 86, 412, 504, 641 ], "type": "list", "angle": 0, "index": 25, "blocks": [ { "bbox": [ 86, 412, 504, 444 ], "type": "text", "angle": 0, "index": 18, "lines": [ { "bbox": [ 109, 412, 505, 426 ], "spans": [ { "bbox": [ 109, 412, 122, 425 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.86 }, { "bbox": [ 122, 413, 505, 426 ], "type": "text", "content": "使用malloc()申请 1024B空间作为缓冲区 buf，申请失败则返回-1，并显示出错信", "score": 1.0 } ] }, { "bbox": [ 88, 430, 107, 446 ], "spans": [ { "bbox": [ 88, 430, 107, 446 ], "type": "text", "content": "息；", "score": 1.0 } ] } ] }, { "bbox": [ 86, 449, 504, 497 ], "type": "text", "angle": 0, "index": 19, "lines": [ { "bbox": [ 109, 449, 502, 461 ], "spans": [ { "bbox": [ 109, 449, 122, 461 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.82 }, { 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"type": "text", "angle": 0, "index": 2, "lines": [ { "bbox": [ 115, 94, 226, 107 ], "spans": [ { "bbox": [ 115, 94, 226, 107 ], "type": "text", "content": "（5）函数需完成的工作：", "score": 1.0 } ] } ] } ], "sub_type": "text" }, { "bbox": [ 107, 111, 408, 179 ], "type": "list", "angle": 0, "index": 8, "blocks": [ { "bbox": [ 107, 111, 355, 125 ], "type": "text", "angle": 0, "index": 4, "lines": [ { "bbox": [ 109, 111, 355, 126 ], "spans": [ { "bbox": [ 109, 111, 122, 125 ], "type": "inline_equation", "content": "\\textcircled{1}", "score": 0.84 }, { "bbox": [ 123, 111, 355, 126 ], "type": "text", "content": "使用 C 库函数 fopen()打开磁盘上的 myfsys 文件；", "score": 1.0 } ] } ] }, { "bbox": [ 107, 130, 408, 143 ], "type": "text", "angle": 0, "index": 5, "lines": [ { "bbox": [ 109, 129, 409, 144 ], "spans": [ { "bbox": [ 109, 130, 122, 142 ], "type": "inline_equation", "content": "\\textcircled{2}", "score": 0.87 }, { "bbox": [ 123, 129, 409, 144 ], "type": "text", "content": "将虚拟磁盘空间中的所有内容保存到磁盘上的 myfsys 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