{"id":1625,"date":"2015-11-12T12:09:23","date_gmt":"2015-11-12T04:09:23","guid":{"rendered":"http:\/\/www.51cos.com\/?p=1625"},"modified":"2015-11-12T12:09:23","modified_gmt":"2015-11-12T04:09:23","slug":"linux%ef%bc%9a%e7%94%a8%e5%9f%ba%e4%ba%8e%e7%ae%a1%e9%81%93%e7%9a%84popen%e5%92%8cpclose%e5%87%bd%e6%95%b0%e4%bb%a3%e6%9b%bfsystem","status":"publish","type":"post","link":"http:\/\/www.51cos.com\/?p=1625","title":{"rendered":"Linux\uff1a\u7528\u57fa\u4e8e\u7ba1\u9053\u7684popen\u548cpclose\u51fd\u6570\u4ee3\u66ffsystem"},"content":{"rendered":"<p>linux\u4e0b\u4f7f\u7528system\u9700\u8981\u8c28\u614e\uff0c\u90a3\u4e48\u4ee3\u66ff\u5b83\u7684\u65b9\u6cd5\u662f\u4ec0\u4e48\u5462\uff1f<\/p>\n<p> \u8fd9\u91cc\u6211\u4eec\u79f0\u8c03\u7528popen\u7684\u8fdb\u7a0b\u4e3a\u7236\u8fdb\u7a0b\uff0c\u7531popen\u542f\u52a8\u7684\u8fdb\u7a0b\u79f0\u4e3a\u5b50\u8fdb\u7a0b\u3002<\/p>\n<p>popen\u51fd\u6570\u8fd8\u521b\u5efa\u4e00\u4e2a\u7ba1\u9053\u7528\u4e8e\u7236\u5b50\u8fdb\u7a0b\u95f4\u901a\u4fe1\u3002\u7236\u8fdb\u7a0b\u8981\u4e48\u4ece\u7ba1\u9053\u8bfb\u4fe1\u606f\uff0c\u8981\u4e48\u5411\u7ba1\u9053\u5199\u4fe1\u606f\uff0c\u81f3\u4e8e\u662f\u8bfb\u8fd8\u662f\u5199\u53d6\u51b3\u4e8e\u7236\u8fdb\u7a0b\u8c03\u7528popen\u65f6\u4f20\u9012\u7684\u53c2\u6570\u3002\u4e0b\u5728\u7ed9\u51fapopen\u3001pclose\u7684\u5b9a\u4e49\uff1a<\/p>\n<pre class=\"prettyprint linenums\" >\n#include <stdio.h><br \/>\n\/*<br \/>\n\u51fd\u6570\u529f\u80fd\uff1apopen\uff08\uff09\u4f1a\u8c03\u7528fork\uff08\uff09\u4ea7\u751f\u5b50\u8fdb\u7a0b\uff0c\u7136\u540e\u4ece\u5b50\u8fdb\u7a0b\u4e2d\u8c03\u7528\/bin\/sh -c\u6765\u6267\u884c\u53c2\u6570command\u7684\u6307\u4ee4\u3002<br \/>\n        \u53c2\u6570type\u53ef\u4f7f\u7528\u201cr\u201d\u4ee3\u8868\u8bfb\u53d6\uff0c\u201cw\u201d\u4ee3\u8868\u5199\u5165\u3002<br \/>\n        \u4f9d\u7167\u6b64type\u503c\uff0cpopen\uff08\uff09\u4f1a\u5efa\u7acb\u7ba1\u9053\u8fde\u5230\u5b50\u8fdb\u7a0b\u7684\u6807\u51c6\u8f93\u51fa\u8bbe\u5907\u6216\u6807\u51c6\u8f93\u5165\u8bbe\u5907\uff0c\u7136\u540e\u8fd4\u56de\u4e00\u4e2a\u6587\u4ef6\u6307\u9488\u3002<br \/>\n        \u968f\u540e\u8fdb\u7a0b\u4fbf\u53ef\u5229\u7528\u6b64\u6587\u4ef6\u6307\u9488\u6765\u8bfb\u53d6\u5b50\u8fdb\u7a0b\u7684\u8f93\u51fa\u8bbe\u5907\u6216\u662f\u5199\u5165\u5230\u5b50\u8fdb\u7a0b\u7684\u6807\u51c6\u8f93\u5165\u8bbe\u5907\u4e2d<br \/>\n\u8fd4\u56de\u503c\uff1a\u82e5\u6210\u529f\u5219\u8fd4\u56de\u6587\u4ef6\u6307\u9488\uff0c\u5426\u5219\u8fd4\u56deNULL\uff0c\u9519\u8bef\u539f\u56e0\u5b58\u4e8eerrno\u4e2d<br \/>\n*\/<br \/>\nFILE * popen( const char * command,const char * type);<\/p>\n<p>\/*<br \/>\n\u51fd\u6570\u529f\u80fd\uff1apclose\uff08\uff09\u7528\u6765\u5173\u95ed\u7531popen\u6240\u5efa\u7acb\u7684\u7ba1\u9053\u53ca\u6587\u4ef6\u6307\u9488\u3002\u53c2\u6570stream\u4e3a\u5148\u524d\u7531popen\uff08\uff09\u6240\u8fd4\u56de\u7684\u6587\u4ef6\u6307\u9488<br \/>\n\u8fd4\u56de\u503c\uff1a\u82e5\u6210\u529f\u8fd4\u56deshell\u7684\u7ec8\u6b62\u72b6\u6001(\u4e5f\u5373\u5b50\u8fdb\u7a0b\u7684\u7ec8\u6b62\u72b6\u6001)\uff0c\u82e5\u51fa\u9519\u8fd4\u56de-1\uff0c\u9519\u8bef\u539f\u56e0\u5b58\u4e8eerrno\u4e2d<br \/>\n*\/<br \/>\nint pclose(FILE * stream);<\/p>\n<p> \u4e0b\u9762\u901a\u8fc7\u4f8b\u5b50\u770b\u4e0bpopen\u7684\u4f7f\u7528\uff1a<\/p>\n<p>\u5047\u5982\u6211\u4eec\u60f3\u53d6\u5f97\u5f53\u524d\u76ee\u5f55\u4e0b\u7684\u6587\u4ef6\u4e2a\u6570\uff0c\u5728shell\u4e0b\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\uff1a <\/p>\n<pre class=\"prettyprint linenums\" >\nls | wc -l<\/p>\n<p>\u6211\u4eec\u53ef\u4ee5\u5728\u7a0b\u5e8f\u4e2d\u8fd9\u6837\u5199\uff1a <\/p>\n<pre class=\"prettyprint linenums\" >\n\/*\u53d6\u5f97\u5f53\u524d\u76ee\u5f55\u4e0b\u7684\u6587\u4ef6\u4e2a\u6570*\/<br \/>\n#include <stdio.h><br \/>\n#include <stdlib.h><br \/>\n#include <errno.h><br \/>\n#include <sys\/wait.h><\/p>\n<p>#define MAXLINE 1024<\/p>\n<p>int main()<br \/>\n{<br \/>\n    char result_buf[MAXLINE], command[MAXLINE];<br \/>\n    int rc = 0; \/\/ \u7528\u4e8e\u63a5\u6536\u547d\u4ee4\u8fd4\u56de\u503c<br \/>\n    FILE *fp;<\/p>\n<p>    \/*\u5c06\u8981\u6267\u884c\u7684\u547d\u4ee4\u5199\u5165buf*\/<br \/>\n    snprintf(command, sizeof(command), \"ls .\/ | wc -l\");<\/p>\n<p>    \/*\u6267\u884c\u9884\u5148\u8bbe\u5b9a\u7684\u547d\u4ee4\uff0c\u5e76\u8bfb\u51fa\u8be5\u547d\u4ee4\u7684\u6807\u51c6\u8f93\u51fa*\/<br \/>\n    fp = popen(command, \"r\");<br \/>\n    if(NULL == fp)<br \/>\n    {<br \/>\n        perror(\"popen\u6267\u884c\u5931\u8d25\uff01\");<br \/>\n        exit(1);<br \/>\n    }<br \/>\n    while(fgets(result_buf, sizeof(result_buf), fp) != NULL)<br \/>\n    {<br \/>\n        \/*\u4e3a\u4e86\u4e0b\u9762\u8f93\u51fa\u597d\u770b\u4e9b\uff0c\u628a\u547d\u4ee4\u8fd4\u56de\u7684\u6362\u884c\u7b26\u53bb\u6389*\/<br \/>\n        if('\\n' == result_buf[strlen(result_buf)-1])<br \/>\n        {<br \/>\n            result_buf[strlen(result_buf)-1] = '\\0';<br \/>\n        }<br \/>\n        printf(\"\u547d\u4ee4\u3010%s\u3011 \u8f93\u51fa\u3010%s\u3011\\r\\n\", command, result_buf);<br \/>\n    }<\/p>\n<p>    \/*\u7b49\u5f85\u547d\u4ee4\u6267\u884c\u5b8c\u6bd5\u5e76\u5173\u95ed\u7ba1\u9053\u53ca\u6587\u4ef6\u6307\u9488*\/<br \/>\n    rc = pclose(fp);<br \/>\n    if(-1 == rc)<br \/>\n    {<br \/>\n        perror(\"\u5173\u95ed\u6587\u4ef6\u6307\u9488\u5931\u8d25\");<br \/>\n        exit(1);<br \/>\n    }<br \/>\n    else<br \/>\n    {<br \/>\n        printf(\"\u547d\u4ee4\u3010%s\u3011\u5b50\u8fdb\u7a0b\u7ed3\u675f\u72b6\u6001\u3010%d\u3011\u547d\u4ee4\u8fd4\u56de\u503c\u3010%d\u3011\\r\\n\", command, rc, WEXITSTATUS(rc));<br \/>\n    }<\/p>\n<p>    return 0;<br \/>\n}<\/p>\n<p> \u7f16\u8bd1\u5e76\u6267\u884c\uff1a<\/p>\n<p><span class=\"katex math inline\">gcc popen.c<\/span> .\/a.out<\/p>\n<p>\u547d\u4ee4\u3010ls .\/ | wc -l\u3011 \u8f93\u51fa\u30102\u3011<\/p>\n<p>\u547d\u4ee4\u3010ls .\/ | wc -l\u3011\u5b50\u8fdb\u7a0b\u7ed3\u675f\u72b6\u6001\u30100\u3011\u547d\u4ee4\u8fd4\u56de\u503c\u30100\u3011<\/p>\n<p>\u4e0a\u9762popen\u53ea\u6355\u83b7\u4e86command\u7684\u6807\u51c6\u8f93\u51fa\uff0c\u5982\u679ccommand\u6267\u884c\u5931\u8d25\uff0c\u5b50\u8fdb\u7a0b\u4f1a\u628a\u9519\u8bef\u4fe1\u606f\u6253\u5370\u5230\u6807\u51c6\u9519\u8bef\u8f93\u51fa\uff0c\u7236\u8fdb\u7a0b\u5c31\u65e0\u6cd5\u83b7\u53d6\u3002\u6bd4\u5982\uff0ccommand\u547d\u4ee4\u4e3a\u201cls nofile.txt\u201d \uff0c\u4e8b\u5b9e\u4e0a\u6211\u4eec\u6839\u672c\u6ca1\u6709nofile.txt\u8fd9\u4e2a\u6587\u4ef6\uff0c\u8fd9\u65f6shell\u4f1a\u8f93\u51fa\u201cls: nofile.txt: No such file or directory\u201d\u3002\u8fd9\u4e2a\u8f93\u51fa\u662f\u5728\u6807\u51c6\u9519\u8bef\u8f93\u51fa\u4e0a\u7684\u3002\u901a\u8fc7\u4e0a\u9762\u7684\u7a0b\u5e8f\u5e76\u65e0\u6cd5\u83b7\u53d6\u3002<\/p>\n<p>\u6ce8\uff1a\u5982\u679c\u4f60\u628a\u4e0a\u9762\u7a0b\u5e8f\u4e2d\u7684command\u8bbe\u6210\u201cls nofile.txt\u201d,\u7f16\u8bd1\u6267\u884c\u7a0b\u5e8f\u4f60\u4f1a\u770b\u5230\u5982\u4e0b\u7ed3\u679c\uff1a<\/p>\n<p><span class=\"katex math inline\">gcc popen.c<\/span> .\/a.out<\/p>\n<p>ls: nofile.txt: No such file or directory<\/p>\n<p>\u547d\u4ee4\u3010ls nofile.txt\u3011\u5b50\u8fdb\u7a0b\u7ed3\u675f\u72b6\u6001\u3010256\u3011\u547d\u4ee4\u8fd4\u56de\u503c\u30101\u3011<\/p>\n<p> \u9700\u8981\u6ce8\u610f\u7684\u662f\u7b2c\u4e00\u884c\u8f93\u51fa\u5e76\u4e0d\u662f\u7236\u8fdb\u7a0b\u7684\u8f93\u51fa\uff0c\u800c\u662f\u5b50\u8fdb\u7a0b\u7684\u6807\u51c6\u9519\u8bef\u8f93\u51fa\u3002<\/p>\n<p>\u6709\u65f6\u5b50\u8fdb\u7a0b\u7684\u9519\u8bef\u4fe1\u606f\u662f\u5f88\u6709\u7528\u7684\uff0c\u90a3\u4e48\u7236\u8fdb\u7a0b\u600e\u4e48\u624d\u80fd\u83b7\u53d6\u5b50\u8fdb\u7a0b\u7684\u9519\u8bef\u4fe1\u606f\u5462\uff1f<\/p>\n<p>\u8fd9\u91cc\u6211\u4eec\u53ef\u4ee5\u91cd\u5b9a\u5411\u5b50\u8fdb\u7a0b\u7684\u9519\u8bef\u8f93\u51fa\uff0c\u8ba9\u9519\u8bef\u8f93\u51fa\u91cd\u5b9a\u5411\u5230\u6807\u51c6\u8f93\u51fa\uff082>&1\uff09\uff0c\u8fd9\u6837\u7236\u8fdb\u7a0b\u5c31\u53ef\u4ee5\u6355\u83b7\u5b50\u8fdb\u7a0b\u7684\u9519\u8bef\u4fe1\u606f\u4e86\u3002\u4f8b\u5982command\u4e3a\u201cls nofile.txt 2>&1\u201d,\u8f93\u51fa\u5982\u4e0b\uff1a<\/p>\n<p>\u547d\u4ee4\u3010ls nofile.txt 2>&1\u3011 \u8f93\u51fa\u3010ls: nofile.txt: No such file or directory\u3011<\/p>\n<p>\u547d\u4ee4\u3010ls nofile.txt 2>&1\u3011\u5b50\u8fdb\u7a0b\u7ed3\u675f\u72b6\u6001\u3010256\u3011\u547d\u4ee4\u8fd4\u56de\u503c\u30101\u3011<\/p>\n<p>\u9644\uff1a\u5b50\u8fdb\u7a0b\u7684\u7ec8\u6b62\u72b6\u6001\u5224\u65ad\u6d89\u53ca\u5230\u7684\u5b8f\uff0c\u8bbe\u8fdb\u7a0b\u7ec8\u6b62\u72b6\u6001\u4e3astatus.<\/p>\n<p>WIFEXITED(status)\u5982\u679c\u5b50\u8fdb\u7a0b\u6b63\u5e38\u7ed3\u675f\u5219\u4e3a\u975e0\u503c\u3002<\/p>\n<p>WEXITSTATUS(status)\u53d6\u5f97\u5b50\u8fdb\u7a0bexit()\u8fd4\u56de\u7684\u7ed3\u675f\u4ee3\u7801\uff0c\u4e00\u822c\u4f1a\u5148\u7528WIFEXITED \u6765\u5224\u65ad\u662f\u5426\u6b63\u5e38\u7ed3\u675f\u624d\u80fd\u4f7f\u7528\u6b64\u5b8f\u3002<\/p>\n<p>WIFSIGNALED(status)\u5982\u679c\u5b50\u8fdb\u7a0b\u662f\u56e0\u4e3a\u4fe1\u53f7\u800c\u7ed3\u675f\u5219\u6b64\u5b8f\u503c\u4e3a\u771f\u3002<\/p>\n<p>WTERMSIG(status)\u53d6\u5f97\u5b50\u8fdb\u7a0b\u56e0\u4fe1\u53f7\u800c\u4e2d\u6b62\u7684\u4fe1\u53f7\u4ee3\u7801\uff0c\u4e00\u822c\u4f1a\u5148\u7528WIFSIGNALED \u6765\u5224\u65ad\u540e\u624d\u4f7f\u7528\u6b64\u5b8f\u3002<\/p>\n<p>WIFSTOPPED(status)\u5982\u679c\u5b50\u8fdb\u7a0b\u5904\u4e8e\u6682\u505c\u6267\u884c\u60c5\u51b5\u5219\u6b64\u5b8f\u503c\u4e3a\u771f\u3002\u4e00\u822c\u53ea\u6709\u4f7f\u7528WUNTRACED \u65f6\u624d\u4f1a\u6709\u6b64\u60c5\u51b5\u3002<\/p>\n<p>WSTOPSIG(status)\u53d6\u5f97\u5f15\u53d1\u5b50\u8fdb\u7a0b\u6682\u505c\u7684\u4fe1\u53f7\u4ee3\u7801\uff0c\u4e00\u822c\u4f1a\u5148\u7528WIFSTOPPED \u6765\u5224\u65ad\u540e\u624d\u4f7f\u7528\u6b64\u5b8f\u3002 <\/p>\n","protected":false},"excerpt":{"rendered":"<p>linux\u4e0b\u4f7f\u7528system\u9700\u8981\u8c28\u614e\uff0c\u90a3\u4e48\u4ee3\u66ff\u5b83\u7684\u65b9\u6cd5\u662f\u4ec0\u4e48\u5462\uff1f \u8fd9\u91cc\u6211\u4eec\u79f0\u8c03\u7528popen\u7684\u8fdb\u7a0b\u4e3a\u7236\u8fdb\u7a0b\uff0c\u7531p [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-1625","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/posts\/1625","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.51cos.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1625"}],"version-history":[{"count":4,"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/posts\/1625\/revisions"}],"predecessor-version":[{"id":1629,"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/posts\/1625\/revisions\/1629"}],"wp:attachment":[{"href":"http:\/\/www.51cos.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1625"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.51cos.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1625"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.51cos.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1625"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}