{"id":114906,"date":"2026-10-10T13:25:11","date_gmt":"2026-10-10T05:25:11","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/114906.html"},"modified":"2026-10-10T13:25:11","modified_gmt":"2026-10-10T05:25:11","slug":"%e3%80%90linux%e3%80%91%e8%bf%9b%e7%a8%8b%e7%a8%8b%e5%ba%8f%e6%9b%bf%e6%8d%a2%e4%b8%8e%e7%ae%80%e9%99%8bshell%e7%bc%96%e5%86%99","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/114906.html","title":{"rendered":"\u3010Linux\u3011\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362\u4e0e\u7b80\u964bShell\u7f16\u5199"},"content":{"rendered":"<p>\u524d\u8a00&#xff1a;\u8fd9\u7bc7\u4ecb\u7ecd\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362&#xff0c;\u8ba4\u8bc6 exec \u51fd\u6570\u65cf&#xff0c;\u518d\u628a\u8fdb\u7a0b\u521b\u5efa\u3001\u7a0b\u5e8f\u66ff\u6362\u548c\u8fdb\u7a0b\u7b49\u5f85\u7ed3\u5408\u8d77\u6765&#xff0c;\u7136\u540e\u518d\u5199\u4e00\u4e2a\u80fd\u6267\u884c\u7b80\u5355\u547d\u4ee4\u7684 Shell\u3002<\/p>\n<hr \/>\n<h3>1.\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362<\/h3>\n<p>\u524d\u9762\u901a\u8fc7 fork \u521b\u5efa\u4e86\u5b50\u8fdb\u7a0b&#xff0c;\u4f46\u7236\u5b50\u8fdb\u7a0b\u8fd0\u884c\u7684\u4ecd\u7136\u662f\u540c\u4e00\u4e2a\u7a0b\u5e8f&#xff0c;\u53ea\u662f\u53ef\u4ee5\u8fdb\u5165\u4e0d\u540c\u7684\u4ee3\u7801\u5206\u652f\u3002<\/p>\n<p>\u5982\u679c\u60f3\u8ba9\u5b50\u8fdb\u7a0b\u53bb\u8fd0\u884c\u53e6\u4e00\u4e2a\u7a0b\u5e8f&#xff0c;\u6bd4\u5982\u6267\u884c ls \u67e5\u770b\u6587\u4ef6&#xff0c;\u8be5\u600e\u4e48\u505a&#xff1f;\u8fd9\u5c31\u9700\u8981\u7528\u5230\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362\u3002<\/p>\n<p>\u7a0b\u5e8f\u66ff\u6362\u4f1a\u628a\u78c1\u76d8\u4e0a\u7684\u53e6\u4e00\u4e2a\u7a0b\u5e8f\u52a0\u8f7d\u8fdb\u6765&#xff0c;\u8ba9\u5f53\u524d\u8fdb\u7a0b\u5f00\u59cb\u6267\u884c\u5b83\u3002\u539f\u7a0b\u5e8f\u7684\u4ee3\u7801\u548c\u6570\u636e\u88ab\u66ff\u6362&#xff0c;\u63a5\u4e0b\u6765\u8fd0\u884c\u7684\u662f\u65b0\u7a0b\u5e8f\u3002<\/p>\n<p>\u8fd9\u91cc\u5148\u8bb0\u4f4f\u4e24\u4e2a\u7ed3\u8bba&#xff1a;<\/p>\n<ul>\n<li>fork \u521b\u5efa\u65b0\u8fdb\u7a0b&#xff0c;exec \u66ff\u6362\u5f53\u524d\u8fdb\u7a0b\u8fd0\u884c\u7684\u7a0b\u5e8f\u3002<\/li>\n<li>\u7a0b\u5e8f\u66ff\u6362\u6210\u529f\u540e&#xff0c;\u4e0d\u4f1a\u518d\u8fd4\u56de\u539f\u6765\u7684\u8c03\u7528\u4f4d\u7f6e&#xff1b;\u66ff\u6362\u5931\u8d25\u624d\u8fd4\u56de -1&#xff0c;\u5e76\u8bbe\u7f6e errno\u3002<\/li>\n<\/ul>\n<p>\u5148\u770b\u4e00\u4e2a\u76f4\u63a5\u8fdb\u884c\u7a0b\u5e8f\u66ff\u6362\u7684\u4f8b\u5b50&#xff1a;<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/10\/20261010052506-6ac9cc3225de5.png\" alt=\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \/><\/p>\n<p>\u7a0b\u5e8f\u5148\u6253\u5370\u201c\u7a0b\u5e8f\u5f00\u59cb\u6267\u884c\u201d&#xff0c;\u968f\u540e\u901a\u8fc7 execl \u6267\u884c ls&#xff0c;\u7ec8\u7aef\u4e0a\u663e\u793a\u7684\u5c31\u662f\u6587\u4ef6\u5217\u8868\u3002\u540e\u9762\u7684\u201c\u7a0b\u5e8f\u6267\u884c\u7ed3\u675f\u201d\u6ca1\u6709\u6253\u5370\u3002<\/p>\n<p>\u8fd9\u91cc\u88ab\u66ff\u6362\u7684\u662f\u6574\u4e2a\u539f\u7a0b\u5e8f&#xff0c;\u4e0d\u6267\u884c\u540e\u534a\u6bb5\u4ee3\u7801\u3002\u66ff\u6362\u6210\u529f\u4ee5\u540e&#xff0c;\u5f53\u524d\u8fdb\u7a0b\u5c31\u53bb\u6267\u884c ls \u4e86&#xff0c;\u7b49 ls \u7ed3\u675f\u4e5f\u4e0d\u4f1a\u56de\u6765\u6253\u5370\u201c\u7a0b\u5e8f\u6267\u884c\u7ed3\u675f\u201d\u3002<\/p>\n<p>\u518d\u6765\u770b\u7236\u5b50\u8fdb\u7a0b\u914d\u5408\u7684\u60c5\u51b5&#xff1a;<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/10\/20261010052506-6ac9cc32eab17.png\" alt=\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \/><\/p>\n<p>\u5148\u7528 fork \u521b\u5efa\u5b50\u8fdb\u7a0b&#xff0c;\u5b50\u8fdb\u7a0b\u6253\u5370\u81ea\u5df1\u7684 PID&#xff0c;\u518d\u6267\u884c execl&#xff0c;\u8fd0\u884c\u5df2\u7ecf\u7f16\u8bd1\u597d\u7684 .\/other\u3002<\/p>\n<p>\u66ff\u6362\u524d\u6253\u5370\u7684\u662f 11173&#xff0c;\u65b0\u7a0b\u5e8f\u6253\u5370\u7684\u4e5f\u662f 11173\u3002\u8fd9\u8bf4\u660e\u6267\u884c\u7a0b\u5e8f\u53d1\u751f\u4e86\u53d8\u5316&#xff0c;\u4f46\u8fd8\u662f\u539f\u6765\u7684\u90a3\u4e2a\u5b50\u8fdb\u7a0b&#xff0c;PID \u6ca1\u53d8\u3002<\/p>\n<p>\u7236\u8fdb\u7a0b\u6ca1\u6709\u8fdb\u884c\u7a0b\u5e8f\u66ff\u6362&#xff0c;\u6240\u4ee5\u5b83\u7b49\u5f85\u5b50\u8fdb\u7a0b\u7ed3\u675f\u4e4b\u540e&#xff0c;\u4ecd\u7136\u53ef\u4ee5\u6253\u5370\u201c\u7a0b\u5e8f\u6267\u884c\u7ed3\u675f\u201d\u3002<\/p>\n<h3>2.exec \u51fd\u6570\u65cf<\/h3>\n<p>\u5e73\u65f6\u8bf4\u7684 exec \u662f\u4e00\u7ec4\u51fd\u6570\u7684\u7edf\u79f0\u3002\u5b83\u4eec\u505a\u7684\u4e8b\u60c5\u76f8\u540c&#xff0c;\u4e3b\u8981\u533a\u522b\u5728\u4e8e&#xff1a;\u600e\u6837\u4f20\u53c2\u6570\u3001\u600e\u6837\u627e\u7a0b\u5e8f\u3001\u7ed9\u65b0\u7a0b\u5e8f\u4ec0\u4e48\u73af\u5883\u53d8\u91cf\u3002<\/p>\n<p>\u51fd\u6570\u540d\u4e0d\u7528\u4e00\u4e2a\u4e2a\u6b7b\u8bb0&#xff0c;\u5148\u770b\u540e\u9762\u7684\u51e0\u4e2a\u5b57\u6bcd&#xff1a;<\/p>\n<table>\n<tr>\u5b57\u6bcd\u542b\u4e49\u600e\u4e48\u7406\u89e3<\/tr>\n<tbody>\n<tr>\n<td>l<\/td>\n<td>list<\/td>\n<td>\u628a\u53c2\u6570\u4e00\u4e2a\u4e2a\u5217\u51fa\u6765<\/td>\n<\/tr>\n<tr>\n<td>v<\/td>\n<td>vector<\/td>\n<td>\u628a\u53c2\u6570\u653e\u5728\u6307\u9488\u6570\u7ec4\u4e2d\u4f20\u5165&#xff0c;\u8fd9\u91cc\u4e0d\u662f C&#043;&#043; \u7684 std::vector<\/td>\n<\/tr>\n<tr>\n<td>p<\/td>\n<td>PATH<\/td>\n<td>\u6587\u4ef6\u540d\u4e0d\u542b \/ \u65f6&#xff0c;\u6309\u7167\u73af\u5883\u53d8\u91cf PATH \u67e5\u627e\u7a0b\u5e8f<\/td>\n<\/tr>\n<tr>\n<td>e<\/td>\n<td>environment<\/td>\n<td>\u81ea\u5df1\u4f20\u5165\u65b0\u7a0b\u5e8f\u8981\u4f7f\u7528\u7684\u73af\u5883\u53d8\u91cf\u8868<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u7ec4\u5408\u8d77\u6765&#xff0c;\u5e38\u89c1\u7684\u51e0\u4e2a\u63a5\u53e3\u5c31\u662f&#xff1a;<\/p>\n<table>\n<tr>\u51fd\u6570\u53c2\u6570\u600e\u4e48\u4f20\u7a0b\u5e8f\u600e\u4e48\u627e\u65b0\u7a0b\u5e8f\u7684\u73af\u5883\u53d8\u91cf<\/tr>\n<tbody>\n<tr>\n<td>execl<\/td>\n<td>\u9010\u4e2a\u5217\u51fa<\/td>\n<td>\u6309\u7ed9\u5b9a\u8def\u5f84<\/td>\n<td>\u4f7f\u7528\u5f53\u524d\u73af\u5883<\/td>\n<\/tr>\n<tr>\n<td>execlp<\/td>\n<td>\u9010\u4e2a\u5217\u51fa<\/td>\n<td>\u53ef\u4ee5\u6309 PATH \u67e5\u627e<\/td>\n<td>\u4f7f\u7528\u5f53\u524d\u73af\u5883<\/td>\n<\/tr>\n<tr>\n<td>execle<\/td>\n<td>\u9010\u4e2a\u5217\u51fa<\/td>\n<td>\u6309\u7ed9\u5b9a\u8def\u5f84<\/td>\n<td>\u7531 envp \u6307\u5b9a<\/td>\n<\/tr>\n<tr>\n<td>execv<\/td>\n<td>\u6307\u9488\u6570\u7ec4<\/td>\n<td>\u6309\u7ed9\u5b9a\u8def\u5f84<\/td>\n<td>\u4f7f\u7528\u5f53\u524d\u73af\u5883<\/td>\n<\/tr>\n<tr>\n<td>execvp<\/td>\n<td>\u6307\u9488\u6570\u7ec4<\/td>\n<td>\u53ef\u4ee5\u6309 PATH \u67e5\u627e<\/td>\n<td>\u4f7f\u7528\u5f53\u524d\u73af\u5883<\/td>\n<\/tr>\n<tr>\n<td>execve<\/td>\n<td>\u6307\u9488\u6570\u7ec4<\/td>\n<td>\u6309\u7ed9\u5b9a\u8def\u5f84<\/td>\n<td>\u7531 envp \u6307\u5b9a<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u8fd9\u91cc\u7684\u8def\u5f84\u65e2\u53ef\u4ee5\u662f \/usr\/bin\/ls \u8fd9\u6837\u7684\u7edd\u5bf9\u8def\u5f84&#xff0c;\u4e5f\u53ef\u4ee5\u662f .\/other \u8fd9\u6837\u7684\u76f8\u5bf9\u8def\u5f84&#xff0c;\u4e0d\u662f\u4e00\u5b9a\u8981\u628a\u5b8c\u6574\u8def\u5f84\u5199\u51fa\u6765\u3002<\/p>\n<h4>2.1execl \u4e0e execlp<\/h4>\n<p>\u5148\u770b execl&#xff0c;\u53ef\u4ee5\u628a\u5b83\u7684\u53c2\u6570\u7406\u89e3\u4e3a&#xff1a;\u6267\u884c\u8c01&#xff0c;\u7ed9\u5b83\u54ea\u4e9b\u53c2\u6570\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/10\/20261010052507-6ac9cc338f7f3.png\" alt=\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \/><\/p>\n<p>\u4e0b\u9762\u7528\u51e0\u6bb5 C \u4ee3\u7801\u8bf4\u660e\u63a5\u53e3\u7528\u6cd5&#xff0c;\u6bcf\u6bb5\u5206\u522b\u7406\u89e3\u5373\u53ef&#xff0c;\u4e0d\u8981\u628a\u5b83\u4eec\u5f53\u4f5c\u4f1a\u4f9d\u6b21\u6267\u884c\u7684\u7a0b\u5e8f\u3002<\/p>\n<p><span class=\"token function\">execl<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\/bin\/ps&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;ps&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;-ef&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>\u8fd9\u51e0\u4e2a\u53c2\u6570\u5206\u522b\u8868\u793a&#xff1a;<\/p>\n<table>\n<tr>\u53c2\u6570\u4f5c\u7528<\/tr>\n<tbody>\n<tr>\n<td>&#034;\/bin\/ps&#034;<\/td>\n<td>\u8981\u6267\u884c\u7684\u7a0b\u5e8f\u8def\u5f84<\/td>\n<\/tr>\n<tr>\n<td>&#034;ps&#034;<\/td>\n<td>\u4f20\u7ed9\u65b0\u7a0b\u5e8f\u7684 argv[0]&#xff0c;\u901a\u5e38\u5199\u7a0b\u5e8f\u540d<\/td>\n<\/tr>\n<tr>\n<td>&#034;-ef&#034;<\/td>\n<td>\u4f20\u7ed9\u65b0\u7a0b\u5e8f\u7684\u9009\u9879&#xff0c;\u5bf9\u5e94 argv[1]<\/td>\n<\/tr>\n<tr>\n<td>NULL<\/td>\n<td>\u8868\u793a\u53c2\u6570\u5217\u8868\u7ed3\u675f<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u7b2c\u4e00\u4e2a &#034;\/bin\/ps&#034; \u662f\u7528\u6765\u627e\u7a0b\u5e8f\u7684&#xff0c;\u540e\u9762\u7684 &#034;ps&#034; \u624d\u662f\u65b0\u7a0b\u5e8f\u770b\u5230\u7684\u7b2c\u4e00\u4e2a\u547d\u4ee4\u884c\u53c2\u6570&#xff0c;\u4e8c\u8005\u7684\u4f5c\u7528\u4e0d\u540c\u3002<\/p>\n<p>\u56fe\u4e2d\u201c\u547d\u4ee4\u884c\u600e\u4e48\u5199\u5c31\u600e\u4e48\u5199\u201d&#xff0c;\u6307\u7684\u662f\u628a\u7a0b\u5e8f\u540d\u548c\u5404\u4e2a\u9009\u9879\u5206\u522b\u4f20\u8fdb\u53bb\u3002\u4f8b\u5982\u524d\u9762\u7684 ls -l -a&#xff0c;\u8981\u5206\u522b\u4f20\u5165 &#034;ls&#034;\u3001&#034;-l&#034;\u3001&#034;-a&#034;&#xff0c;\u4e0d\u80fd\u628a\u6574\u6761\u547d\u4ee4\u5f53\u6210\u4e00\u4e2a\u5b57\u7b26\u4e32\u4ea4\u7ed9 execl \u89e3\u6790\u3002<\/p>\n<p>\u672b\u5c3e\u8981\u4f20\u7684\u662f\u7a7a\u6307\u9488\u3002\u5728 execl \u8fd9\u7c7b\u53ef\u53d8\u53c2\u6570\u51fd\u6570\u4e2d&#xff0c;\u53ef\u4ee5\u7528 (char *)NULL \u660e\u786e\u5b83\u7684\u7c7b\u578b\u3002<\/p>\n<p>execlp \u6bd4 execl \u591a\u4e86\u4e00\u4e2a p&#xff0c;\u4f7f\u7528\u8d77\u6765\u66f4\u63a5\u8fd1\u5e73\u65f6\u8f93\u5165\u547d\u4ee4\u7684\u4e60\u60ef&#xff1a;<\/p>\n<p><span class=\"token function\">execlp<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;ps&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;ps&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;-ef&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/10\/20261010052508-6ac9cc344cbc0.png\" alt=\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \/><\/p>\n<p>\u8fd9\u91cc\u7b2c\u4e00\u4e2a\u53c2\u6570\u53ea\u5199 &#034;ps&#034;&#xff0c;\u51fd\u6570\u5c31\u4f1a\u6309\u7167\u5f53\u524d\u73af\u5883\u53d8\u91cf PATH \u4e2d\u7684\u76ee\u5f55\u53bb\u67e5\u627e\u3002<\/p>\n<p>\u9700\u8981\u6ce8\u610f\u7684\u662f&#xff0c;\u53ea\u6709\u6587\u4ef6\u540d\u4e2d\u4e0d\u542b \/ \u65f6\u624d\u8fd9\u6837\u641c\u7d22\u3002\u5982\u679c\u4f20\u5165\u7684\u662f .\/other \u6216 \/bin\/ps&#xff0c;\u5c31\u6309\u7167\u7ed9\u5b9a\u8def\u5f84\u6267\u884c\u3002<\/p>\n<h4>2.2execv \u4e0e execvp<\/h4>\n<p>\u53c2\u6570\u6570\u91cf\u5c11\u65f6&#xff0c;\u4e00\u4e2a\u4e2a\u5217\u51fa\u6765\u6bd4\u8f83\u76f4\u89c2&#xff1b;\u5982\u679c\u53c2\u6570\u662f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u624d\u62ff\u5230\u7684&#xff0c;\u653e\u8fdb\u6570\u7ec4\u4f1a\u65b9\u4fbf\u5f88\u591a\u3002<\/p>\n<p>execv \u4f7f\u7528\u7684\u5c31\u662f\u4ee5\u7a7a\u6307\u9488\u7ed3\u5c3e\u7684\u53c2\u6570\u6570\u7ec4&#xff1a;<\/p>\n<p><span class=\"token keyword\">char<\/span> <span class=\"token operator\">*<\/span><span class=\"token keyword\">const<\/span> argv<span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token string\">&#034;ps&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;-ef&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">execv<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\/bin\/ps&#034;<\/span><span class=\"token punctuation\">,<\/span> argv<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>\u6570\u7ec4\u4e2d&#xff0c;argv[0] \u662f &#034;ps&#034;&#xff0c;argv[1] \u662f &#034;-ef&#034;&#xff0c;\u6700\u540e\u4e00\u4e2a\u5143\u7d20\u4e3a NULL\u3002\u63a5\u53e3\u901a\u8fc7\u8fd9\u4e2a\u7a7a\u6307\u9488\u77e5\u9053\u53c2\u6570\u5df2\u7ecf\u7ed3\u675f\u3002<\/p>\n<p>\u5982\u679c\u8fd8\u60f3\u6309\u7167 PATH \u67e5\u627e&#xff0c;\u5c31\u6cbf\u7528\u8fd9\u4e2a\u6570\u7ec4&#xff0c;\u6539\u7528 execvp&#xff1a;<\/p>\n<p><span class=\"token function\">execvp<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;ps&#034;<\/span><span class=\"token punctuation\">,<\/span> argv<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>execvp \u5f88\u9002\u5408\u7528\u6765\u7f16\u5199\u7b80\u964b Shell\u3002 \u56e0\u4e3a\u7528\u6237\u8fd9\u4e00\u884c\u8f93\u5165\u4e86\u51e0\u4e2a\u53c2\u6570&#xff0c;\u6211\u4eec\u4e8b\u5148\u5e76\u4e0d\u77e5\u9053&#xff1b;\u8bfb\u53d6\u547d\u4ee4\u540e&#xff0c;\u628a\u5b83\u62c6\u6210\u6570\u7ec4&#xff0c;\u518d\u4ea4\u7ed9 execvp \u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n<p>\u8fd9\u91cc\u7684\u6570\u7ec4\u793a\u4f8b\u6309 C \u5199\u6cd5\u7406\u89e3&#xff0c;\u540e\u9762\u7684 Shell \u5219\u4f7f\u7528 C&#043;&#043; \u5b9e\u73b0&#xff0c;\u53c2\u6570\u76f4\u63a5\u6307\u5411\u8bfb\u5165\u7684\u547d\u4ee4\u5b57\u7b26\u4e32\u3002<\/p>\n<h4>2.3\u73af\u5883\u53d8\u91cf\u600e\u4e48\u4f20<\/h4>\n<p>\u6ca1\u6709 e \u7684\u63a5\u53e3&#xff0c;\u4f1a\u628a\u5f53\u524d\u8fdb\u7a0b\u7684\u73af\u5883\u53d8\u91cf\u4ea4\u7ed9\u65b0\u7a0b\u5e8f&#xff1b;\u5e26 e \u7684\u63a5\u53e3&#xff0c;\u5219\u4f7f\u7528\u6211\u4eec\u6307\u5b9a\u7684\u73af\u5883\u53d8\u91cf\u8868\u3002<\/p>\n<p>\u6cbf\u7528\u524d\u9762\u7684 argv&#xff0c;\u53ef\u4ee5\u8fd9\u6837\u4e3a execve \u6307\u5b9a\u73af\u5883\u53d8\u91cf&#xff1a;<\/p>\n<p><span class=\"token keyword\">char<\/span> <span class=\"token operator\">*<\/span><span class=\"token keyword\">const<\/span> envp<span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token string\">&#034;PATH&#061;\/bin:\/usr\/bin&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;TERM&#061;console&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">execve<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\/bin\/ps&#034;<\/span><span class=\"token punctuation\">,<\/span> argv<span class=\"token punctuation\">,<\/span> envp<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>argv \u91cc\u653e\u547d\u4ee4\u884c\u53c2\u6570&#xff0c;envp \u91cc\u653e\u73af\u5883\u53d8\u91cf\u3002\u5b83\u4eec\u90fd\u662f\u6307\u9488\u6570\u7ec4&#xff0c;\u4e5f\u90fd\u4ee5\u7a7a\u6307\u9488\u7ed3\u5c3e&#xff0c;\u53ea\u662f\u91cc\u9762\u7684\u5b57\u7b26\u4e32\u542b\u4e49\u4e0d\u540c\u3002<\/p>\n<p>\u73af\u5883\u53d8\u91cf\u6309 \u540d\u5b57&#061;\u5185\u5bb9 \u7684\u5f62\u5f0f\u7ec4\u7ec7\u3002\u4f8b\u5982\u4e0a\u9762\u7684 PATH&#061;\/bin:\/usr\/bin&#xff0c;\u5c31\u662f\u65b0\u7a0b\u5e8f\u80fd\u62ff\u5230\u7684\u4e00\u4e2a\u73af\u5883\u53d8\u91cf\u3002\u663e\u5f0f\u4f20\u5165 envp \u65f6&#xff0c;\u65b0\u7a0b\u5e8f\u4f7f\u7528\u7684\u5c31\u662f\u8fd9\u5f20\u8868&#xff0c;\u4e0d\u4f1a\u81ea\u52a8\u628a\u9057\u6f0f\u7684\u539f\u73af\u5883\u53d8\u91cf\u8865\u8fdb\u6765\u3002<\/p>\n<p>\u53e6\u5916\u8fd8\u80fd\u770b\u5230\u628a v\u3001p\u3001e \u5408\u5728\u4e00\u8d77\u7684 execvpe&#xff1a;<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/10\/20261010052509-6ac9cc357e24c.png\" alt=\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \/><\/p>\n<p>\u8fd9\u4e9b\u63a5\u53e3\u6700\u7ec8\u5b8c\u6210\u7684\u662f\u540c\u4e00\u4ef6\u4e8b\u3002\u5728\u4e0a\u9762\u5217\u51fa\u7684\u516d\u4e2a\u63a5\u53e3\u4e2d&#xff0c;execve \u662f\u7cfb\u7edf\u8c03\u7528&#xff0c;\u5176\u4ed6\u51e0\u4e2a\u662f\u5728\u5b83\u7684\u57fa\u7840\u4e0a\u63d0\u4f9b\u66f4\u65b9\u4fbf\u7684\u4f20\u53c2\u3001\u67e5\u627e\u65b9\u5f0f\u3002\u5148\u6839\u636e\u53c2\u6570\u5f62\u5f0f\u9009\u63a5\u53e3&#xff0c;\u5177\u4f53\u58f0\u660e\u9700\u8981\u65f6\u518d\u67e5\u5c31\u884c\u3002<\/p>\n<h3>3.\u7f16\u5199\u4e00\u4e2a\u7b80\u964b Shell<\/h3>\n<p>\u73b0\u5728\u628a\u524d\u9762\u7684\u5185\u5bb9\u8fde\u8d77\u6765\u3002\u6211\u4eec\u8f93\u5165 ls&#xff0c;\u7ec8\u7aef\u5c31\u80fd\u5217\u51fa\u6587\u4ef6&#xff0c;\u662f\u56e0\u4e3a Shell \u8bfb\u5230\u4e86\u547d\u4ee4&#xff0c;\u7136\u540e\u8ba9\u76f8\u5e94\u7684\u7a0b\u5e8f\u53bb\u6267\u884c\u3002<\/p>\n<p>\u5bf9\u4e8e\u8fd9\u91cc\u8981\u5b9e\u73b0\u7684\u7b80\u5355\u5916\u90e8\u547d\u4ee4&#xff0c;\u6d41\u7a0b\u5c31\u662f&#xff1a;<\/p>\n<p>\u6253\u5370\u63d0\u793a\u7b26 \u2192 \u8bfb\u53d6\u547d\u4ee4 \u2192 \u62c6\u5206\u53c2\u6570 \u2192 \u521b\u5efa\u5b50\u8fdb\u7a0b \u2192 \u5b50\u8fdb\u7a0b\u66ff\u6362\u7a0b\u5e8f \u2192 \u7236\u8fdb\u7a0b\u7b49\u5f85 \u2192 \u7ee7\u7eed\u8bfb\u53d6\u4e0b\u4e00\u6761\u547d\u4ee4\u3002<\/p>\n<p>\u4e3a\u4ec0\u4e48\u4e0d\u8ba9 Shell \u81ea\u5df1\u76f4\u63a5\u8c03\u7528 exec&#xff1f;\u56e0\u4e3a\u66ff\u6362\u6210\u529f\u4ee5\u540e&#xff0c;\u5b83\u81ea\u5df1\u5c31\u53bb\u8fd0\u884c ls \u4e86&#xff0c;\u539f\u6765\u7684\u8bfb\u547d\u4ee4\u5faa\u73af\u4e5f\u6ca1\u4e86\u3002\u6240\u4ee5\u9700\u8981\u8ba9\u5b50\u8fdb\u7a0b\u6267\u884c\u5916\u90e8\u7a0b\u5e8f&#xff0c;\u7236\u8fdb\u7a0b\u7ee7\u7eed\u4fdd\u7559 Shell \u7684\u5de5\u4f5c\u3002<\/p>\n<p>\u9664\u6b64\u4e4b\u5916&#xff0c;\u8fd8\u8981\u63d0\u524d\u5224\u65ad\u662f\u4e0d\u662f\u5185\u5efa\u547d\u4ee4\u3002\u8fd9\u4efd\u5b9e\u73b0\u4e2d\u7684 cd \u548c echo&#xff0c;\u4f1a\u76f4\u63a5\u5728 Shell \u8fdb\u7a0b\u4e2d\u5904\u7406\u3002<\/p>\n<h4>3.1\u6587\u4ef6\u5212\u5206\u4e0e\u4e3b\u5faa\u73af<\/h4>\n<p>\u6574\u4e2a\u5b9e\u73b0\u5206\u4e3a\u4e09\u4e2a\u6587\u4ef6&#xff1a;<\/p>\n<table>\n<tr>\u6587\u4ef6\u5185\u5bb9<\/tr>\n<tbody>\n<tr>\n<td>myShell.h<\/td>\n<td>\u5934\u6587\u4ef6\u3001\u5e38\u91cf\u3001\u5168\u5c40\u53d8\u91cf\u58f0\u660e\u548c\u51fd\u6570\u58f0\u660e<\/td>\n<\/tr>\n<tr>\n<td>myShell.cpp<\/td>\n<td>\u63d0\u793a\u7b26\u3001\u547d\u4ee4\u8bfb\u53d6\u3001\u53c2\u6570\u62c6\u5206\u3001\u5185\u5efa\u547d\u4ee4\u548c\u5916\u90e8\u547d\u4ee4\u6267\u884c<\/td>\n<\/tr>\n<tr>\n<td>main.cpp<\/td>\n<td>\u628a\u5404\u4e2a\u6b65\u9aa4\u7ec4\u7ec7\u6210\u5faa\u73af<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u5148\u770b myShell.h&#xff1a;<\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;stdio.h&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;cstring&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;stdlib.h&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;string&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;unistd.h&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;iostream&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;sys\/types.h&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;sys\/wait.h&gt;<\/span><\/span><\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">FORMAT<\/span> <span class=\"token string\">&#034;[%s&#064;%s %s]#&#034;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">COMMAND_SIZE<\/span> <span class=\"token expression\"><span class=\"token number\">1024<\/span><\/span><\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u547d\u4ee4\u884c\u53c2\u6570\u8868<\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">MAXARGC<\/span> <span class=\"token expression\"><span class=\"token number\">248<\/span><\/span><\/span><br \/>\n<span class=\"token keyword\">extern<\/span> <span class=\"token keyword\">char<\/span> <span class=\"token operator\">*<\/span>g_argv<span class=\"token punctuation\">[<\/span>MAXARGC<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">extern<\/span> <span class=\"token keyword\">int<\/span> g_argc<span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u73af\u5883\u53d8\u91cf\u8868<\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">MAXENVS<\/span> <span class=\"token expression\"><span class=\"token number\">248<\/span><\/span><\/span><br \/>\n<span class=\"token keyword\">extern<\/span> <span class=\"token keyword\">char<\/span> <span class=\"token operator\">*<\/span>g_env<span class=\"token punctuation\">[<\/span>MAXENVS<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">extern<\/span> <span class=\"token keyword\">int<\/span> g_envc<span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u6a21\u62df\u8fdb\u7a0b\u5de5\u4f5c\u8def\u5f84<\/span><br \/>\n<span class=\"token keyword\">extern<\/span> <span class=\"token keyword\">char<\/span> cwd<span class=\"token punctuation\">[<\/span><span class=\"token number\">1024<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">extern<\/span> <span class=\"token keyword\">char<\/span> cwdenv<span class=\"token punctuation\">[<\/span><span class=\"token number\">1024<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u9000\u51fa\u7801<\/span><br \/>\n<span class=\"token keyword\">extern<\/span> <span class=\"token keyword\">int<\/span> lastcode<span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u521d\u59cb\u5316\u73af\u5883\u53d8\u91cf<\/span><br \/>\n<span class=\"token keyword\">void<\/span> <span class=\"token function\">InitEvn<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u6253\u5370\u547d\u4ee4\u884c<\/span><br \/>\n<span class=\"token keyword\">void<\/span> <span class=\"token function\">PrintCommandPrompt<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u83b7\u53d6\u7528\u6237\u8f93\u5165<\/span><br \/>\n<span class=\"token keyword\">bool<\/span> <span class=\"token function\">GetCommandLine<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> commandline<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">int<\/span> size<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u5904\u7406\u547d\u4ee4<\/span><br \/>\n<span class=\"token keyword\">bool<\/span> <span class=\"token function\">CommandParse<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> commandline<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u5904\u7406\u5185\u8054\u547d\u4ee4<\/span><br \/>\n<span class=\"token keyword\">bool<\/span> <span class=\"token function\">CheckExecBuiltin<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u6267\u884c<\/span><br \/>\n<span class=\"token keyword\">int<\/span> <span class=\"token function\">ExecCommand<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>g_argv \u4fdd\u5b58\u62c6\u5206\u540e\u7684\u547d\u4ee4\u884c\u53c2\u6570&#xff0c;g_argc \u8bb0\u5f55\u53c2\u6570\u4e2a\u6570&#xff1b;g_env \u4fdd\u5b58\u73af\u5883\u53d8\u91cf\u5b57\u7b26\u4e32&#xff0c;g_envc \u8bb0\u5f55\u6570\u91cf\u3002lastcode \u7528\u6765\u4fdd\u5b58\u540e\u9762\u53d6\u5f97\u7684\u5916\u90e8\u547d\u4ee4\u9000\u51fa\u7801\u3002<\/p>\n<p>cwd \u548c cwdenv \u867d\u7136\u90fd\u4e0e\u8def\u5f84\u6709\u5173&#xff0c;\u7528\u9014\u5374\u4e0d\u540c&#xff1a;\u524d\u8005\u653e\u5f53\u524d\u5de5\u4f5c\u76ee\u5f55&#xff0c;\u540e\u8005\u653e PWD&#061;\u8def\u5f84 \u8fd9\u6837\u7684\u73af\u5883\u53d8\u91cf\u5b57\u7b26\u4e32\u3002<\/p>\n<p>\u518d\u770b main.cpp&#xff0c;\u5148\u4ece\u6574\u4f53\u4e0a\u4e86\u89e3\u6267\u884c\u987a\u5e8f&#xff1a;<\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&#034;myShell.h&#034;<\/span><\/span><\/p>\n<p><span class=\"token keyword\">int<\/span> <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n   <span class=\"token function\">InitEvn<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n   <span class=\"token keyword\">while<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><br \/>\n   <span class=\"token punctuation\">{<\/span><br \/>\n       <span class=\"token function\">PrintCommandPrompt<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n       <span class=\"token keyword\">char<\/span> commandline<span class=\"token punctuation\">[<\/span>COMMAND_SIZE<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n       <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token operator\">!<\/span><span class=\"token function\">GetCommandLine<\/span><span class=\"token punctuation\">(<\/span>commandline<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">sizeof<\/span><span class=\"token punctuation\">(<\/span>commandline<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\n           <span class=\"token keyword\">continue<\/span><span class=\"token punctuation\">;<\/span><br \/>\n       <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token operator\">!<\/span><span class=\"token function\">CommandParse<\/span><span class=\"token punctuation\">(<\/span>commandline<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\n           <span class=\"token keyword\">continue<\/span><span class=\"token punctuation\">;<\/span><br \/>\n       <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">CheckExecBuiltin<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\n           <span class=\"token keyword\">continue<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>       <span class=\"token function\">ExecCommand<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>   <span class=\"token punctuation\">}<\/span><\/p>\n<p>   <span class=\"token keyword\">return<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u542f\u52a8\u65f6\u5148\u521d\u59cb\u5316\u73af\u5883&#xff0c;\u4e4b\u540e\u4e0d\u65ad\u6253\u5370\u63d0\u793a\u7b26\u3001\u83b7\u53d6\u547d\u4ee4\u3001\u62c6\u5206\u53c2\u6570\u3002<\/p>\n<p>\u5982\u679c\u672c\u8f6e\u6ca1\u6709\u8bfb\u5230\u6709\u6548\u8f93\u5165&#xff0c;\u5c31\u901a\u8fc7 continue \u91cd\u65b0\u5f00\u59cb&#xff1b;\u5982\u679c\u547d\u4e2d\u4e86\u5185\u5efa\u547d\u4ee4&#xff0c;\u5904\u7406\u5b8c\u4e5f\u76f4\u63a5\u8fdb\u5165\u4e0b\u4e00\u8f6e\u3002\u5269\u4e0b\u7684\u547d\u4ee4\u624d\u4ea4\u7ed9 ExecCommand\u3002<\/p>\n<p>\u4e0b\u9762\u6309\u529f\u80fd\u5c55\u5f00 myShell.cpp&#xff0c;\u5404\u6bb5\u6309\u987a\u5e8f\u63a5\u8d77\u6765\u5c31\u662f\u8fd9\u4e2a\u6587\u4ef6\u7684\u5185\u5bb9\u3002<\/p>\n<h4>3.2\u73af\u5883\u53d8\u91cf\u4e0e\u547d\u4ee4\u63d0\u793a\u7b26<\/h4>\n<p>\u5148\u5b9a\u4e49\u5168\u5c40\u53d8\u91cf&#xff0c;\u5e76\u5b8c\u6210\u73af\u5883\u53d8\u91cf\u7684\u521d\u59cb\u5316&#xff1a;<\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&#034;myShell.h&#034;<\/span><\/span><\/p>\n<p><span class=\"token keyword\">char<\/span> <span class=\"token operator\">*<\/span>g_argv<span class=\"token punctuation\">[<\/span>MAXARGC<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">int<\/span> g_argc <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">char<\/span> <span class=\"token operator\">*<\/span>g_env<span class=\"token punctuation\">[<\/span>MAXENVS<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">int<\/span> g_envc <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">int<\/span> lastcode <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">char<\/span> cwd<span class=\"token punctuation\">[<\/span><span class=\"token number\">1024<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">char<\/span> cwdenv<span class=\"token punctuation\">[<\/span><span class=\"token number\">1024<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">void<\/span> <span class=\"token function\">InitEvn<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">extern<\/span> <span class=\"token keyword\">char<\/span> <span class=\"token operator\">*<\/span><span class=\"token operator\">*<\/span>environ<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token function\">memset<\/span><span class=\"token punctuation\">(<\/span>g_env<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">sizeof<\/span><span class=\"token punctuation\">(<\/span>g_env<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    g_envc <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">for<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">int<\/span> i <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span> environ<span class=\"token punctuation\">[<\/span>i<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span> i<span class=\"token operator\">&#043;&#043;<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        g_env<span class=\"token punctuation\">[<\/span>i<span class=\"token punctuation\">]<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span><span class=\"token function\">malloc<\/span><span class=\"token punctuation\">(<\/span><span class=\"token function\">strlen<\/span><span class=\"token punctuation\">(<\/span>environ<span class=\"token punctuation\">[<\/span>i<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">strcpy<\/span><span class=\"token punctuation\">(<\/span>g_env<span class=\"token punctuation\">[<\/span>i<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">,<\/span> environ<span class=\"token punctuation\">[<\/span>i<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">putenv<\/span><span class=\"token punctuation\">(<\/span>g_env<span class=\"token punctuation\">[<\/span>i<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        g_envc <span class=\"token operator\">&#043;&#061;<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span> <\/p>\n<p><span class=\"token punctuation\">}<\/span><\/p>\n<p>environ \u6307\u5411\u5f53\u524d\u8fdb\u7a0b\u7684\u73af\u5883\u53d8\u91cf\u8868&#xff0c;\u91cc\u9762\u4fdd\u5b58\u7684\u662f\u4e00\u4e2a\u4e2a \u540d\u5b57&#061;\u5185\u5bb9 \u5b57\u7b26\u4e32\u3002<\/p>\n<p>\u5faa\u73af\u53d6\u51fa\u8fd9\u4e9b\u5b57\u7b26\u4e32&#xff0c;\u7533\u8bf7\u7a7a\u95f4\u3001\u590d\u5236\u5185\u5bb9&#xff0c;\u518d\u8c03\u7528 putenv \u653e\u5230\u5f53\u524d\u8fdb\u7a0b\u7684\u73af\u5883\u4e2d\u3002\u8fd9\u91cc\u7684 g_env \u4fdd\u5b58\u8fd9\u4e9b\u5b57\u7b26\u4e32\u7684\u5730\u5740\u3002<\/p>\n<p>putenv \u4f1a\u7ee7\u7eed\u4f7f\u7528\u4f20\u5165\u7684\u90a3\u5757\u5b57\u7b26\u4e32\u7a7a\u95f4&#xff0c;\u6240\u4ee5\u8fd9\u91cc\u7528 malloc \u5206\u914d\u7684\u7a7a\u95f4\u4e0d\u80fd\u5728\u653e\u8fdb\u53bb\u540e\u9a6c\u4e0a\u91ca\u653e\u3002\u540e\u9762\u4fdd\u5b58 PWD \u7684 cwdenv \u4e5f\u662f\u5168\u5c40\u6570\u7ec4&#xff0c;\u51fd\u6570\u8fd4\u56de\u540e\u4ecd\u7136\u5b58\u5728\u3002<\/p>\n<p>\u63a5\u4e0b\u6765\u83b7\u53d6\u63d0\u793a\u7b26\u9700\u8981\u7684\u4fe1\u606f&#xff1a;<\/p>\n<p><span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> <span class=\"token function\">GetUserName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> name <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">getenv<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;USER&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> name <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token constant\">NULL<\/span> <span class=\"token operator\">?<\/span> <span class=\"token string\">&#034;None&#034;<\/span> <span class=\"token operator\">:<\/span> name<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> <span class=\"token function\">GetHostName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> hostName <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">getenv<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;HOSTNAME&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> hostName <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token constant\">NULL<\/span> <span class=\"token operator\">?<\/span> <span class=\"token string\">&#034;None&#034;<\/span> <span class=\"token operator\">:<\/span> hostName<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> <span class=\"token function\">GetPwd<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">getcwd<\/span><span class=\"token punctuation\">(<\/span>cwd<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">sizeof<\/span><span class=\"token punctuation\">(<\/span>cwd<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">!&#061;<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token function\">snprintf<\/span><span class=\"token punctuation\">(<\/span>cwdenv<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">sizeof<\/span><span class=\"token punctuation\">(<\/span>cwdenv<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;PWD&#061;%s&#034;<\/span><span class=\"token punctuation\">,<\/span> cwd<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">putenv<\/span><span class=\"token punctuation\">(<\/span>cwdenv<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u540c\u6b65\u7ef4\u62a4\u5f53\u524d\u8fdb\u7a0b\u7684 PWD \u73af\u5883\u53d8\u91cf<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> cwd<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> <span class=\"token string\">&#034;None&#034;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> <span class=\"token function\">GetHome<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> home <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">getenv<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;HOME&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> home <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token constant\">NULL<\/span> <span class=\"token operator\">?<\/span> <span class=\"token string\">&#034;None&#034;<\/span> <span class=\"token operator\">:<\/span> home<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>std<span class=\"token double-colon punctuation\">::<\/span>string <span class=\"token function\">CutPwd<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> pwd<span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    std<span class=\"token double-colon punctuation\">::<\/span>string <span class=\"token function\">str<\/span><span class=\"token punctuation\">(<\/span>pwd<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>str <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token string\">&#034;\/&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> str<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token keyword\">auto<\/span> pos <span class=\"token operator\">&#061;<\/span> str<span class=\"token punctuation\">.<\/span><span class=\"token function\">rfind<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\/&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pos <span class=\"token operator\">&#061;&#061;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>string<span class=\"token double-colon punctuation\">::<\/span>npos<span class=\"token punctuation\">)<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> <span class=\"token string\">&#034;BUG&#034;<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token keyword\">return<\/span> str<span class=\"token punctuation\">.<\/span><span class=\"token function\">substr<\/span><span class=\"token punctuation\">(<\/span>pos <span class=\"token operator\">&#043;<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <\/p>\n<p><span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token keyword\">void<\/span> <span class=\"token function\">PrintCommandPrompt<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">char<\/span> commandLine<span class=\"token punctuation\">[<\/span>COMMAND_SIZE<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token function\">snprintf<\/span><span class=\"token punctuation\">(<\/span>commandLine<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">sizeof<\/span><span class=\"token punctuation\">(<\/span>commandLine<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> FORMAT<span class=\"token punctuation\">,<\/span> <span class=\"token function\">GetUserName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">GetHostName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">CutPwd<\/span><span class=\"token punctuation\">(<\/span><span class=\"token function\">GetPwd<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">.<\/span><span class=\"token function\">c_str<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token function\">printf<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;%s&#034;<\/span><span class=\"token punctuation\">,<\/span> commandLine<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token function\">fflush<\/span><span class=\"token punctuation\">(<\/span><span class=\"token constant\">stdout<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u8fd9\u4e00\u6bb5\u4e3b\u8981\u505a\u4e09\u4ef6\u4e8b\u3002<\/p>\n<p>\u9996\u5148&#xff0c;getenv \u901a\u8fc7\u540d\u5b57\u8bfb\u53d6\u73af\u5883\u53d8\u91cf\u3002GetUserName \u8bfb\u53d6 USER&#xff0c;GetHostName \u8bfb\u53d6 HOSTNAME&#xff0c;GetHome \u8bfb\u53d6 HOME\u3002\u5982\u679c\u5bf9\u5e94\u53d8\u91cf\u4e0d\u5b58\u5728&#xff0c;\u5c31\u8fd4\u56de &#034;None&#034;\u3002<\/p>\n<p>\u5176\u6b21&#xff0c;GetPwd \u7528 getcwd \u53d6\u5f97\u8fdb\u7a0b\u5f53\u524d\u7684\u5de5\u4f5c\u76ee\u5f55&#xff0c;\u518d\u628a\u5b83\u7ec4\u7ec7\u6210 PWD&#061;&#8230; \u653e\u5165\u73af\u5883\u53d8\u91cf\u3002**\u5b9e\u9645\u5de5\u4f5c\u76ee\u5f55\u7531\u8fdb\u7a0b\u7ef4\u62a4&#xff0c;\u6211\u8fd9\u91cc\u53ea\u662f\u7b80\u5355\u7684\u6a21\u62df\u4e00\u4e0b\u3002<\/p>\n<p>CutPwd \u5219\u53d6\u8def\u5f84\u6700\u540e\u4e00\u6bb5&#xff0c;\u8ba9\u63d0\u793a\u7b26\u77ed\u4e00\u4e9b\u3002\u4f8b\u5982\u5b8c\u6574\u8def\u5f84\u4e3a \/home\/hjy\/MyShell&#xff0c;\u63d0\u793a\u7b26\u91cc\u53ea\u663e\u793a MyShell&#xff1b;\u5982\u679c\u5f53\u524d\u5c31\u5728\u6839\u76ee\u5f55 \/&#xff0c;\u5219\u76f4\u63a5\u4fdd\u7559 \/\u3002<\/p>\n<p>\u6700\u540e&#xff0c;PrintCommandPrompt \u6309\u7167 FORMAT \u62fc\u63a5\u5e76\u6253\u5370\u63d0\u793a\u7b26\u3002\u8fd9\u91cc\u6ca1\u6709\u6253\u5370\u6362\u884c&#xff0c;\u56e0\u6b64\u7d27\u8ddf\u4e00\u4e2a fflush(stdout)&#xff0c;\u8ba9\u63d0\u793a\u7b26\u53ca\u65f6\u663e\u793a\u51fa\u6765&#xff0c;\u518d\u7b49\u7528\u6237\u8f93\u5165\u3002<\/p>\n<p>\u672b\u5c3e\u7684 # \u4e5f\u662f\u6211\u4eec\u81ea\u5df1\u6253\u5370\u7684\u5b57\u7b26&#xff0c;\u4e3b\u8981\u662f\u672a\u6765\u505a\u533a\u5206\u5e76\u4e0d\u662f\u83b7\u5f97\u4e86root\u8eab\u4efd\u3002<\/p>\n<h4>3.3\u8bfb\u53d6\u547d\u4ee4\u5e76\u62c6\u5206\u53c2\u6570<\/h4>\n<p>Shell \u8bfb\u5230\u7684\u9996\u5148\u662f\u4e00\u6574\u884c\u5b57\u7b26\u4e32\u3002\u8981\u4ea4\u7ed9 execvp&#xff0c;\u8fd8\u9700\u8981\u628a\u7a0b\u5e8f\u540d\u548c\u5404\u4e2a\u53c2\u6570\u62c6\u51fa\u6765&#xff1a;<\/p>\n<p><span class=\"token keyword\">bool<\/span> <span class=\"token function\">GetCommandLine<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> commandline<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">int<\/span> size<span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">char<\/span> <span class=\"token operator\">*<\/span>tmp <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">fgets<\/span><span class=\"token punctuation\">(<\/span>commandline<span class=\"token punctuation\">,<\/span> size<span class=\"token punctuation\">,<\/span> <span class=\"token constant\">stdin<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>tmp <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">false<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    commandline<span class=\"token punctuation\">[<\/span><span class=\"token function\">strlen<\/span><span class=\"token punctuation\">(<\/span>commandline<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&#8211;<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u6e05\u7406 \\\\n<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">strlen<\/span><span class=\"token punctuation\">(<\/span>commandline<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">false<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">true<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token keyword\">bool<\/span> <span class=\"token function\">CommandParse<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> commandline<span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">BLANK<\/span> <span class=\"token string\">&#034; &#034;<\/span><\/span><br \/>\n    g_argc <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    g_argv<span class=\"token punctuation\">[<\/span>g_argc<span class=\"token operator\">&#043;&#043;<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">strtok<\/span><span class=\"token punctuation\">(<\/span>commandline<span class=\"token punctuation\">,<\/span> BLANK<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">while<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">bool<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">(<\/span>g_argv<span class=\"token punctuation\">[<\/span>g_argc<span class=\"token operator\">&#043;&#043;<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">strtok<\/span><span class=\"token punctuation\">(<\/span><span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">,<\/span> BLANK<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    g_argc <span class=\"token operator\">-&#061;<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> g_argc <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">0<\/span> <span class=\"token operator\">?<\/span> <span class=\"token boolean\">true<\/span> <span class=\"token operator\">:<\/span> <span class=\"token boolean\">false<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>fgets \u4ece\u6807\u51c6\u8f93\u5165\u8bfb\u53d6\u4e00\u884c\u5185\u5bb9\u3002\u5728\u6b63\u5e38\u8f93\u5165\u4e00\u884c\u5e76\u6309\u4e0b\u56de\u8f66\u7684\u60c5\u51b5\u4e0b&#xff0c;\u7ed3\u5c3e\u4f1a\u5e26\u6709 \\\\n&#xff0c;\u6240\u4ee5\u4ee3\u7801\u628a\u6700\u540e\u4e00\u4e2a\u5b57\u7b26\u6539\u6210 0&#xff0c;\u53bb\u6389\u8fd9\u4e2a\u6362\u884c\u3002<\/p>\n<p>\u5982\u679c\u53ea\u6309\u56de\u8f66&#xff0c;\u53bb\u6389\u6362\u884c\u540e\u5c31\u662f\u7a7a\u5b57\u7b26\u4e32&#xff0c;\u5f53\u524d\u8fd9\u8f6e\u4e0d\u6267\u884c\u547d\u4ee4\u3002<\/p>\n<p>\u63a5\u4e0b\u6765\u7528 strtok \u6309\u7a7a\u683c\u62c6\u5206\u3002\u6bd4\u5982\u8f93\u5165 ls -l -a&#xff0c;\u62c6\u5b8c\u4e4b\u540e\u5c31\u662f&#xff1a;<\/p>\n<table>\n<tr>\u6570\u7ec4\u4f4d\u7f6e\u4fdd\u5b58\u7684\u5185\u5bb9<\/tr>\n<tbody>\n<tr>\n<td>g_argv[0]<\/td>\n<td>\u6307\u5411 &#034;ls&#034;<\/td>\n<\/tr>\n<tr>\n<td>g_argv[1]<\/td>\n<td>\u6307\u5411 &#034;-l&#034;<\/td>\n<\/tr>\n<tr>\n<td>g_argv[2]<\/td>\n<td>\u6307\u5411 &#034;-a&#034;<\/td>\n<\/tr>\n<tr>\n<td>g_argv[3]<\/td>\n<td>\u7a7a\u6307\u9488<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u7b2c\u4e00\u6b21\u8c03\u7528 strtok \u65f6\u4f20\u5165 commandline&#xff0c;\u540e\u9762\u4f20\u5165 NULL&#xff0c;\u8868\u793a\u7ee7\u7eed\u62c6\u5206\u521a\u624d\u90a3\u4e00\u884c\u3002\u5b83\u4f1a\u4fee\u6539\u539f\u5b57\u7b26\u4e32&#xff0c;\u628a\u5206\u9694\u4f4d\u7f6e\u6539\u6210\u5b57\u7b26\u4e32\u7ed3\u675f\u7b26&#xff0c;\u518d\u8fd4\u56de\u5404\u6bb5\u7684\u5730\u5740\u3002<\/p>\n<h4>3.4\u5185\u5efa\u547d\u4ee4 cd \u4e0e echo<\/h4>\n<p>\u666e\u901a\u5916\u90e8\u547d\u4ee4\u53ef\u4ee5\u4ea4\u7ed9\u5b50\u8fdb\u7a0b\u6267\u884c&#xff0c;\u4f46 cd \u8981\u5355\u72ec\u5904\u7406\u3002<\/p>\n<p>\u5b50\u8fdb\u7a0b\u6539\u53d8\u81ea\u5df1\u7684\u5de5\u4f5c\u76ee\u5f55&#xff0c;\u4e0d\u4f1a\u6539\u53d8\u7236\u8fdb\u7a0b\u7684\u5de5\u4f5c\u76ee\u5f55\u3002 \u5982\u679c\u628a cd \u653e\u5230\u5b50\u8fdb\u7a0b\u4e2d&#xff0c;\u7b49\u5b50\u8fdb\u7a0b\u9000\u51fa&#xff0c;Shell \u81ea\u5df1\u8fd8\u7559\u5728\u539f\u6765\u7684\u76ee\u5f55&#xff0c;\u4e0b\u4e00\u6761\u547d\u4ee4\u4e5f\u5c31\u6ca1\u6709\u771f\u6b63\u201c\u5207\u6362\u8fc7\u53bb\u201d\u3002<\/p>\n<p>\u56e0\u6b64&#xff0c;cd \u5fc5\u987b\u5728\u5f53\u524d Shell \u8fdb\u7a0b\u4e2d\u6267\u884c\u3002\u8fd9\u91cc\u4e5f\u628a echo \u653e\u5728\u5185\u90e8\u5904\u7406&#xff0c;\u65b9\u4fbf\u6253\u5370\u6587\u5b57\u3001\u67e5\u770b\u73af\u5883\u53d8\u91cf\u548c\u4fdd\u5b58\u7684\u9000\u51fa\u7801&#xff1a;<\/p>\n<p><span class=\"token keyword\">void<\/span> <span class=\"token function\">Cd<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>g_argc <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token comment\">\/\/ \u56de\u5230\u5bb6\u76ee\u5f55<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> homedir <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">GetHome<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">chdir<\/span><span class=\"token punctuation\">(<\/span>homedir<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token keyword\">else<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        std<span class=\"token double-colon punctuation\">::<\/span>string <span class=\"token function\">where<\/span><span class=\"token punctuation\">(<\/span>g_argv<span class=\"token punctuation\">[<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>where <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token string\">&#034;~&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\n        <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token function\">chdir<\/span><span class=\"token punctuation\">(<\/span><span class=\"token function\">GetHome<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token keyword\">else<\/span><br \/>\n        <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token function\">chdir<\/span><span class=\"token punctuation\">(<\/span>where<span class=\"token punctuation\">.<\/span><span class=\"token function\">c_str<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token keyword\">void<\/span> <span class=\"token function\">Echo<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>g_argc <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token number\">2<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        std<span class=\"token double-colon punctuation\">::<\/span>string opt <span class=\"token operator\">&#061;<\/span> g_argv<span class=\"token punctuation\">[<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>opt <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token string\">&#034;$?&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\n        <span class=\"token punctuation\">{<\/span><br \/>\n            std<span class=\"token double-colon punctuation\">::<\/span>cout <span class=\"token operator\">&lt;&lt;<\/span> lastcode <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><br \/>\n            lastcode <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token keyword\">else<\/span> <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>opt<span class=\"token punctuation\">[<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token char\">&#039;$&#039;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token comment\">\/\/ \u83b7\u53d6\u73af\u5883\u53d8\u91cf<\/span><br \/>\n        <span class=\"token punctuation\">{<\/span><br \/>\n            std<span class=\"token double-colon punctuation\">::<\/span>string envName <span class=\"token operator\">&#061;<\/span> opt<span class=\"token punctuation\">.<\/span><span class=\"token function\">substr<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> envValue <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">getenv<\/span><span class=\"token punctuation\">(<\/span>envName<span class=\"token punctuation\">.<\/span><span class=\"token function\">c_str<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>envValue <span class=\"token operator\">!&#061;<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span><br \/>\n                std<span class=\"token double-colon punctuation\">::<\/span>cout <span class=\"token operator\">&lt;&lt;<\/span> envValue <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token keyword\">else<\/span><br \/>\n                std<span class=\"token double-colon punctuation\">::<\/span>cout <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token keyword\">else<\/span><br \/>\n        <span class=\"token punctuation\">{<\/span><br \/>\n            std<span class=\"token double-colon punctuation\">::<\/span>cout <span class=\"token operator\">&lt;&lt;<\/span> opt <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token keyword\">bool<\/span> <span class=\"token function\">CheckExecBuiltin<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    std<span class=\"token double-colon punctuation\">::<\/span>string <span class=\"token function\">command<\/span><span class=\"token punctuation\">(<\/span>g_argv<span class=\"token punctuation\">[<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>command <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token string\">&#034;cd&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token function\">Cd<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">true<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token keyword\">else<\/span> <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>command <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token string\">&#034;echo&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token function\">Echo<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">true<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">false<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token punctuation\">}<\/span><\/p>\n<p>Cd \u7684\u5904\u7406\u6bd4\u8f83\u76f4\u63a5&#xff1a;<\/p>\n<ul>\n<li>\u53ea\u6709 cd&#xff0c;\u6ca1\u6709\u5176\u4ed6\u53c2\u6570&#xff1a;\u901a\u8fc7 HOME \u56de\u5230\u5bb6\u76ee\u5f55\u3002<\/li>\n<li>\u53c2\u6570\u6070\u597d\u662f ~&#xff1a;\u540c\u6837\u56de\u5230\u5bb6\u76ee\u5f55\u3002<\/li>\n<li>\u4f20\u5165\u5176\u4ed6\u8def\u5f84&#xff1a;\u628a\u8fd9\u4e2a\u8def\u5f84\u4ea4\u7ed9 chdir\u3002<\/li>\n<\/ul>\n<p>chdir \u6210\u529f\u540e&#xff0c;Shell \u8fdb\u7a0b\u7684\u5de5\u4f5c\u76ee\u5f55\u53d1\u751f\u53d8\u5316\u3002\u4e0b\u4e00\u6b21\u6253\u5370\u63d0\u793a\u7b26\u65f6&#xff0c;GetPwd \u4f1a\u91cd\u65b0\u53d6\u5f97\u8def\u5f84&#xff0c;\u5e76\u66f4\u65b0 PWD&#xff0c;\u540e\u9762\u521b\u5efa\u7684\u5b50\u8fdb\u7a0b\u4e5f\u4f1a\u7ee7\u627f\u8fd9\u4e2a\u5de5\u4f5c\u76ee\u5f55\u3002<\/p>\n<p>\u6211\u53ea\u5b9e\u73b0\u4e86\u4e00\u5c0f\u90e8\u5206\u529f\u80fd&#xff0c;\u6bd5\u7adf\u4e3b\u8981\u76ee\u7684\u8fd8\u662f\u5b66\u4e60\u3002<\/p>\n<p>Echo \u5219\u53ea\u5904\u7406\u547d\u4ee4\u540e\u9762\u6070\u597d\u6709\u4e00\u4e2a\u53c2\u6570\u7684\u60c5\u51b5&#xff1a;<\/p>\n<table>\n<tr>\u8f93\u5165\u5f62\u5f0f\u8fd9\u91cc\u7684\u5904\u7406\u65b9\u5f0f<\/tr>\n<tbody>\n<tr>\n<td>echo hello<\/td>\n<td>\u6253\u5370 hello<\/td>\n<\/tr>\n<tr>\n<td>echo $HOME<\/td>\n<td>\u901a\u8fc7 getenv \u8bfb\u53d6 HOME \u5e76\u6253\u5370<\/td>\n<\/tr>\n<tr>\n<td>echo $?<\/td>\n<td>\u6253\u5370 lastcode&#xff0c;\u968f\u540e\u628a\u5b83\u8bbe\u7f6e\u4e3a 0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u8fd9\u91cc\u7684 $HOME\u3001$? \u662f Echo \u51fd\u6570\u81ea\u5df1\u5224\u65ad\u5e76\u5904\u7406\u7684&#xff0c;\u8fd8\u6ca1\u6709\u5b9e\u73b0\u5bf9\u6240\u6709\u547d\u4ee4\u901a\u7528\u7684\u53d8\u91cf\u66ff\u6362\u3002<\/p>\n<p>CheckExecBuiltin \u8d1f\u8d23\u770b\u547d\u4ee4\u540d\u662f\u4e0d\u662f cd \u6216 echo&#xff0c;\u5982\u679c\u662f\u5c31\u6267\u884c\u5bf9\u5e94\u51fd\u6570&#xff0c;\u5e76\u8fd4\u56de true\u3002\u4e3b\u5faa\u73af\u62ff\u5230\u8fd9\u4e2a\u7ed3\u679c&#xff0c;\u76f4\u63a5\u8fdb\u5165\u4e0b\u4e00\u8f6e&#xff0c;\u4e0d\u518d\u521b\u5efa\u5b50\u8fdb\u7a0b\u3002<\/p>\n<h4>3.5\u6267\u884c\u5916\u90e8\u547d\u4ee4\u5e76\u7b49\u5f85<\/h4>\n<p>\u547d\u4ee4\u8bfb\u53d6\u3001\u53c2\u6570\u6570\u7ec4\u548c\u5185\u5efa\u547d\u4ee4\u90fd\u51c6\u5907\u597d\u4e4b\u540e&#xff0c;\u5916\u90e8\u547d\u4ee4\u7684\u6267\u884c\u90e8\u5206\u53cd\u800c\u4e0d\u957f&#xff1a;<\/p>\n<p><span class=\"token keyword\">int<\/span> <span class=\"token function\">ExecCommand<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n    pid_t id <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">fork<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>id <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ child<\/span><br \/>\n        <span class=\"token function\">execvp<\/span><span class=\"token punctuation\">(<\/span>g_argv<span class=\"token punctuation\">[<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">,<\/span> g_argv<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token keyword\">int<\/span> status <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    pid_t rid <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">waitpid<\/span><span class=\"token punctuation\">(<\/span>id<span class=\"token punctuation\">,<\/span> <span class=\"token operator\">&amp;<\/span>status<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>rid <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token punctuation\">{<\/span><br \/>\n        lastcode <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">WEXITSTATUS<\/span><span class=\"token punctuation\">(<\/span>status<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">return<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u5148\u901a\u8fc7 fork \u521b\u5efa\u5b50\u8fdb\u7a0b\u3002\u5b50\u8fdb\u7a0b\u4e2d id &#061;&#061; 0&#xff0c;\u4e8e\u662f\u8c03\u7528&#xff1a;execvp(g_argv[0], g_argv)\u3002<\/p>\n<p>\u8fd9\u91cc\u7684\u4e24\u4e2a\u53c2\u6570\u6b63\u597d\u5bf9\u5e94\u524d\u9762\u62c6\u5206\u7684\u7ed3\u679c&#xff1a;<\/p>\n<ul>\n<li>g_argv[0]&#xff1a;\u8981\u6267\u884c\u7684\u7a0b\u5e8f\u540d&#xff0c;\u6bd4\u5982 ls\u3002<\/li>\n<li>g_argv&#xff1a;\u5b8c\u6574\u53c2\u6570\u6570\u7ec4&#xff0c;\u5176\u4e2d\u5305\u62ec\u7a0b\u5e8f\u540d\u3001\u9009\u9879\u4ee5\u53ca\u672b\u5c3e\u7684\u7a7a\u6307\u9488\u3002<\/li>\n<\/ul>\n<p>execvp \u6210\u529f\u540e&#xff0c;\u5b50\u8fdb\u7a0b\u5c31\u53bb\u8fd0\u884c\u5916\u90e8\u7a0b\u5e8f&#xff1b;\u53ea\u6709\u5931\u8d25\u624d\u4f1a\u6267\u884c exit(1)&#xff0c;\u907f\u514d\u7ee7\u7eed\u8fdb\u5165 Shell \u7684\u8bfb\u547d\u4ee4\u5faa\u73af\u3002<\/p>\n<p>\u7236\u8fdb\u7a0b\u8d70\u5230 waitpid(id, &amp;status, 0)&#xff0c;\u963b\u585e\u7b49\u5f85\u521a\u624d\u521b\u5efa\u7684\u5b50\u8fdb\u7a0b\u3002<\/p>\n<p>\u7b49\u5b50\u8fdb\u7a0b\u7ed3\u675f&#xff0c;\u7236\u8fdb\u7a0b\u56de\u6536\u5b83\u7684\u8d44\u6e90&#xff0c;\u5e76\u4ece status \u4e2d\u53d6\u5f97\u9000\u51fa\u7801&#xff0c;\u4fdd\u5b58\u5230 lastcode\u3002\u7136\u540e ExecCommand \u8fd4\u56de&#xff0c;\u4e3b\u5faa\u73af\u518d\u6b21\u6253\u5370\u63d0\u793a\u7b26&#xff0c;\u7b49\u5f85\u4e0b\u4e00\u6761\u547d\u4ee4\u3002<\/p>\n<p>\u6765\u770b\u7b80\u5355\u5916\u90e8\u547d\u4ee4\u7684\u8fd0\u884c\u6548\u679c&#xff1a;<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/10\/20261010052510-6ac9cc366f26d.png\" alt=\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \/><\/p>\n<p>\u8fdb\u5165\u81ea\u5236 Shell \u540e&#xff0c;\u5206\u522b\u8f93\u5165 ls\u3001pwd\u3001whoami&#xff0c;\u80fd\u770b\u5230\u6587\u4ef6\u5217\u8868\u3001\u5f53\u524d\u8def\u5f84\u548c\u7528\u6237\u540d\u3002\u6bcf\u6267\u884c\u5b8c\u4e00\u6761\u547d\u4ee4&#xff0c;\u63d0\u793a\u7b26\u90fd\u4f1a\u91cd\u65b0\u51fa\u73b0&#xff0c;\u8bf4\u660e\u7236\u8fdb\u7a0b\u4e00\u76f4\u4fdd\u7559\u7740\u8bfb\u547d\u4ee4\u7684\u5faa\u73af\u3002<\/p>\n<hr \/>\n<p>\u5b8c<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u524d\u8a00&#xff1a;\u8fd9\u7bc7\u4ecb\u7ecd\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362&#xff0c;\u8ba4\u8bc6 exec \u51fd\u6570\u65cf&#xff0c;\u518d\u628a\u8fdb\u7a0b\u521b\u5efa\u3001\u7a0b\u5e8f\u66ff\u6362\u548c\u8fdb\u7a0b\u7b49\u5f85\u7ed3\u5408\u8d77\u6765&#xff0c;\u7136\u540e\u518d\u5199\u4e00\u4e2a\u80fd\u6267\u884c\u7b80\u5355\u547d\u4ee4\u7684 Shell\u30021.\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362<br \/>\n\u524d\u9762\u901a\u8fc7 fork \u521b\u5efa\u4e86\u5b50\u8fdb\u7a0b&#xff0c;\u4f46\u7236\u5b50\u8fdb\u7a0b\u8fd0\u884c\u7684\u4ecd\u7136\u662f\u540c\u4e00\u4e2a\u7a0b\u5e8f&#xff0c;\u53ea\u662f\u53ef\u4ee5\u8fdb\u5165\u4e0d\u540c\u7684\u4ee3\u7801\u5206\u652f\u3002<br \/>\n\u5982\u679c\u60f3\u8ba9\u5b50\u8fdb\u7a0b\u53bb\u8fd0\u884c\u53e6\u4e00\u4e2a\u7a0b\u5e8f&#xff0c;\u6bd4\u5982\u6267\u884c ls \u67e5\u770b\u6587\u4ef6&#xff0c;\u8be5\u600e\u4e48\u505a&#xff1f;\u8fd9\u5c31\u9700\u8981\u7528\u5230\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362\u3002<br \/>\n\u7a0b\u5e8f\u66ff<\/p>\n","protected":false},"author":2,"featured_media":114900,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[9098,58,149,305,44],"topic":[],"class_list":["post-114906","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server","tag-it","tag-linux","tag-windows","tag-305","tag-44"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v20.3 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>\u3010Linux\u3011\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362\u4e0e\u7b80\u964bShell\u7f16\u5199 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/114906.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"\u3010Linux\u3011\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362\u4e0e\u7b80\u964bShell\u7f16\u5199 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"\u524d\u8a00&#xff1a;\u8fd9\u7bc7\u4ecb\u7ecd\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362&#xff0c;\u8ba4\u8bc6 exec \u51fd\u6570\u65cf&#xff0c;\u518d\u628a\u8fdb\u7a0b\u521b\u5efa\u3001\u7a0b\u5e8f\u66ff\u6362\u548c\u8fdb\u7a0b\u7b49\u5f85\u7ed3\u5408\u8d77\u6765&#xff0c;\u7136\u540e\u518d\u5199\u4e00\u4e2a\u80fd\u6267\u884c\u7b80\u5355\u547d\u4ee4\u7684 Shell\u30021.\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362 \u524d\u9762\u901a\u8fc7 fork \u521b\u5efa\u4e86\u5b50\u8fdb\u7a0b&#xff0c;\u4f46\u7236\u5b50\u8fdb\u7a0b\u8fd0\u884c\u7684\u4ecd\u7136\u662f\u540c\u4e00\u4e2a\u7a0b\u5e8f&#xff0c;\u53ea\u662f\u53ef\u4ee5\u8fdb\u5165\u4e0d\u540c\u7684\u4ee3\u7801\u5206\u652f\u3002 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