pid_t\u00a0<\/span> fork<\/span>(void<\/span>);<\/p>\n \u8fd4\u56de\u503c：\u5b50\u8fdb\u7a0b\u4e2d\u8fd4\u56de0，\u2f57\u8fdb\u7a0b\u8fd4\u56de\u2f26\u8fdb\u7a0bid，\u51fa\u9519\u8fd4\u56de-1<\/p>\n \u8fdb\u7a0b\u8c03\u2f64fork，\u5f53\u63a7\u5236\u8f6c\u79fb\u5230\u5185\u6838\u4e2d\u7684fork\u4ee3\u7801\u540e，\u5185\u6838\u505a：<\/p>\n \u5f53\u2f00\u4e2a\u8fdb\u7a0b\u8c03\u2f64fork\u4e4b\u540e，\u5c31\u6709\u4e24\u4e2a\u2f06\u8fdb\u5236\u4ee3\u7801\u76f8\u540c\u7684\u8fdb\u7a0b\u3002\u2f7d\u4e14\u5b83\u4eec\u90fd\u8fd0\u2f8f\u5230\u76f8\u540c\u7684\u5730\u2f45\u3002\u4f46\u6bcf\u4e2a\u8fdb\u7a0b\u90fd\u5c06\u53ef\u4ee5\u5f00\u59cb\u5b83\u4eec\u2f83\u2f30\u7684\u65c5\u7a0b，\u5982\u4e0b\u56fe：<\/p>\n \u6240\u4ee5，fork\u4e4b\u524d\u2f57\u8fdb\u7a0b\u72ec\u2f74\u6267\u2f8f，fork\u4e4b\u540e，\u2f57\u2f26\u4e24\u4e2a\u6267\u2f8f\u6d41\u5206\u522b\u6267\u2f8f\u3002\u6ce8\u610f，fork\u4e4b\u540e，\u8c01\u5148\u6267\u2f8f\u5b8c\u5168\u7531\u8c03\u5ea6\u5668\u51b3\u5b9a\u3002<\/p>\n \u901a\u5e38，\u2f57\u2f26\u4ee3\u7801\u5171\u4eab，\u2f57\u2f26\u5728\u4e0d\u5199\u2f0a\u65f6，\u6570\u636e\u4e5f\u662f\u5171\u4eab\u7684，\u5f53\u4efb\u610f\u2f00\u2f45\u8bd5\u56fe\u5199\u2f0a，\u4fbf\u4ee5\u5199\u65f6\u62f7\u2ec9\u7684\u2f45\u5f0f\u5404\u2f83\u2f00\u4efd\u526f\u672c\u3002\u5177\u4f53\u2ec5\u4e0b\u56fe:<\/p>\n \u8be6\u7ec6\u89e3\u91ca：\u7236\u8fdb\u7a0b\u521b\u5efa\u5b50\u8fdb\u7a0b\u540e，\u66f4\u65b0\u9875\u8868\u4e2d\u8868\u793a\u6570\u636e\u8bbf\u95ee\u6743\u9650\u7684\u6807\u5fd7\u4f4d\u4e3a\u53ea\u8bfb\u5c5e\u6027，\u5f53\u7236\u5b50\u8fdb\u7a0b\u4e2d\u7684\u67d0\u4e00\u65b9\u5199\u5165\u6570\u636e\u65f6，\u89e6\u53d1\u7cfb\u7edf\u9519\u8bef，\u8fdb\u800c\u5f15\u53d1\u7f3a\u9875\u4e2d\u65ad，\u7136\u540e\u7cfb\u7edf\u5c31\u4f1a\u8fdb\u884c\u4e00\u7cfb\u5217\u8f83\u4e3a\u590d\u6742\u7684\u68c0\u6d4b，\u5f53\u5224\u5b9a\u9700\u8981\u53d1\u751f\u5199\u5b9e\u62f7\u8d1d\u540e，\u5c31\u4f1a\u5f00\u59cb\u7533\u8bf7\u5185\u5b58，\u53d1\u751f\u62f7\u8d1d，\u4fee\u6539\u7236\u5b50\u9875\u8868\u5bf9\u5e94\u6570\u636e\u7684\u6743\u9650\u4e3a\u53ef\u8bfb\u53ef\u5199，\u7136\u540e\u6062\u590d\u6267\u884c\u3002<\/p>\n \u610f\u4e49：\u56e0\u4e3a\u6709\u5199\u65f6\u62f7\u2ec9\u6280\u672f\u7684\u5b58\u5728,\u6240\u4ee5\u2f57\u2f26\u8fdb\u7a0b\u5f97\u4ee5\u5f7b\u5e95\u5206\u79bb\u79bb！\u5b8c\u6210\u4e86\u8fdb\u7a0b\u72ec\u2f74\u6027\u7684\u6280\u672f\u4fdd\u8bc1!<\/p>\n \u5199\u65f6\u62f7\u2ec9，\u662f\u2f00\u79cd\u5ef6\u65f6\u7533\u8bf7\u6280\u672f，\u53ef\u4ee5\u63d0\u2fbc\u6574\u673a\u5185\u5b58\u7684\u4f7f\u2f64\u7387\u3002<\/p>\n \u8fdb\u7a0b\u7ec8\u2f4c\u7684\u672c\u8d28\u662f\u91ca\u653e\u7cfb\u7edf\u8d44\u6e90，\u5c31\u662f\u91ca\u653e\u8fdb\u7a0b\u7533\u8bf7\u7684\u76f8\u5173\u5185\u6838\u6570\u636e\u7ed3\u6784\u548c\u5bf9\u5e94\u7684\u6570\u636e\u548c\u4ee3\u7801\u3002<\/p>\n \u6240\u6709\u4fe1\u53f7：<\/p>\n \u6b63\u5e38\u7ec8\u2f4c（\u53ef\u4ee5\u901a\u8fc7 echo $? \u67e5\u770b\u8fdb\u7a0b\u9000\u51fa\u7801）：<\/p>\n \u5f02\u5e38\u9000\u51fa：<\/p>\n \u9000\u51fa\u7801（\u9000\u51fa\u72b6\u6001）\u53ef\u4ee5\u544a\u8bc9\u6211\u4eec\u6700\u540e\u2f00\u6b21\u6267\u2f8f\u7684\u547d\u4ee4\u7684\u72b6\u6001\u3002\u5728\u547d\u4ee4\u7ed3\u675f\u4ee5\u540e，\u6211\u4eec\u53ef\u4ee5\u77e5\u9053\u547d\u4ee4\u662f\u6210\u529f\u5b8c\u6210\u7684\u8fd8\u662f\u4ee5\u9519\u8bef\u7ed3\u675f\u7684\u3002\u5176\u57fa\u672c\u601d\u60f3\u662f，\u7a0b\u5e8f\u8fd4\u56de\u9000\u51fa\u4ee3\u7801 0 \u65f6\u8868\u2f70\u6267\u2f8f\u6210\u529f，\u6ca1\u6709\u95ee\u9898\u3002 \u4ee3\u7801 1 \u6216 0 \u4ee5\u5916\u7684\u4efb\u4f55\u4ee3\u7801\u90fd\u88ab\u89c6\u4e3a\u4e0d\u6210\u529f\u3002\u901a\u8fc7\u9519\u8bef\u7801，\u6211\u4eec\u53ef\u4ee5\u8ba9\u7236\u8fdb\u7a0b\u6216\u7cfb\u7edf\u66f4\u597d\u7684\u4e86\u89e3\u5f53\u524d\u8fdb\u7a0b\u662f\u6210\u529f\u4e86\u8fd8\u662f\u5931\u8d25\u4e86，\u5982\u679c\u5931\u8d25\u4e86\u662f\u56e0\u4e3a\u4ec0\u4e48\u5931\u8d25\u7684\u3002<\/p>\n Linux Shell \u4e2d\u7684\u4e3b\u8981\u9000\u51fa\u7801：<\/p>\n \u793a\u4f8b\u4ee3\u7801：<\/p>\n 1 #include<iostream> \u6548\u679c：<\/p>\n \u89e3\u91ca：C\u8bed\u8a00\u4e2d\u63d0\u4f9b\u4e86\u53ef\u4ee5\u67e5\u770b\u5f53\u524d\u9519\u8bef\u7801\u7684\u5168\u5c40\u53d8\u91cferrno，\u53ea\u8981\u5305\u542berrno.h\u5934\u6587\u4ef6\u5c31\u53ef\u4ee5\u4f7f\u7528，\u8fd8\u63d0\u4f9b\u4e86\u5c06\u9519\u8bef\u7801\u8f6c\u6362\u4e3a\u5bf9\u5e94\u9519\u8bef\u4fe1\u606f\u7684strerror\u51fd\u6570\u3002<\/p>\n #<\/span>include<\/span><unistd.h><\/span><\/p>\n void <\/span>_exit(int<\/span> status);<\/p>\n \u53c2\u6570：status \u5b9a\u4e49\u4e86\u8fdb\u7a0b\u7684\u7ec8\u2f4c\u72b6\u6001，\u2f57\u8fdb\u7a0b\u901a\u8fc7wait\u6765\u83b7\u53d6\u8be5\u503c<\/p>\n \u8bf4\u660e：\u867d\u7136status\u662fint，\u4f46\u662f\u4ec5\u6709\u4f4e8\u4f4d\u53ef\u4ee5\u88ab\u2f57\u8fdb\u7a0b\u6240\u2f64\u3002\u6240\u4ee5_exit(-1)\u65f6，\u5728\u7ec8\u7aef\u6267\u2f8f$?\u53d1\u73b0 \u8fd4\u56de\u503c\u662f255\u3002<\/p>\n \u793a\u4f8b\u4ee3\u7801\u4e00：<\/p>\n 1 #include<iostream> \u6548\u679c：<\/p>\n \u89e3\u91ca：\u53ef\u4ee5\u770b\u5230 "\u8fdb\u7a0b\u7ed3\u675f\u4e86"\u8fd9\u53e5\u8bdd\u5e76\u6ca1\u6709\u6253\u5370，\u6240\u4ee5\u5f97\u5230\u7ed3\u8bba\u00a0_exit \u65b9\u6cd5\u7684\u4f5c\u7528\u662f\u7ed3\u675f\u6574\u4e2a\u8fdb\u7a0b\u3002<\/p>\n \u793a\u4f8b\u4ee3\u7801\u4e8c：<\/p>\n #include<stdio.h> int main() return 0; \u6548\u679c：<\/p>\n \u89e3\u91ca：\u4ece\u4e0a\u9762\u4ee3\u7801\u53ef\u4ee5\u5f97\u5230\u7ed3\u8bba，_exit \u7ed3\u675f\u8fdb\u7a0b\u65f6，\u5982\u679c\u7f13\u51b2\u533a\u5185\u6709\u6570\u636e，_exit \u4e0d\u4f1a\u5237\u65b0\u3002<\/p>\n #<\/span>include<\/span><unistd.h><\/span><\/p>\n void\u00a0\u00a0<\/span>exit(int<\/span> status);<\/p>\n exit\u6700\u540e\u4e5f\u4f1a\u8c03\u2f64_exit，\u4f46\u5728\u8c03\u2f64_exit\u4e4b\u524d，\u8fd8\u505a\u4e86\u5176\u4ed6\u2f2f\u4f5c：<\/p>\n \u793a\u4f8b\u4ee3\u7801\u4e00：<\/p>\n 1 #include<iostream> \u6548\u679c：<\/p>\n \u89e3\u91ca：\u53ef\u4ee5\u770b\u5230 "\u8fdb\u7a0b\u7ed3\u675f\u4e86"\u8fd9\u53e5\u8bdd\u5e76\u6ca1\u6709\u6253\u5370，\u6240\u4ee5\u5f97\u5230\u7ed3\u8bba\u00a0exit \u65b9\u6cd5\u7684\u4f5c\u7528\u662f\u7ed3\u675f\u6574\u4e2a\u8fdb\u7a0b\u3002<\/p>\n \u793a\u4f8b\u4ee3\u7801\u4e8c：<\/p>\n #include<stdio.h> int main() return 0; \u6548\u679c：<\/p>\n \u89e3\u91ca：\u6211\u4eec\u53ef\u4ee5\u770b\u5230 "\u8fdb\u7a0b\u7ed3\u675f\u4e86"\u8fd9\u53e5\u8bdd\u6253\u5370\u51fa\u6765\u4e86，\u8fd9\u91cc\u4ee3\u7801\u6211\u4eec\u6ca1\u6709\u901a\u8fc7 '\\\\n' \u5f3a\u5236\u5237\u65b0\u7f13\u51b2\u533a，\u6240\u4ee5\u8bf4\u660e exit \u65b9\u6cd5\u7ed3\u675f\u8fdb\u7a0b\u524d\u4f1a\u4e3b\u52a8\u5e2e\u6211\u4eec\u5237\u65b0\u7f13\u51b2\u533a\u3002<\/p>\n \u793a\u4f8b\u4ee3\u7801：<\/p>\n 1 #include<iostream> \u6548\u679c：<\/p>\n \u89e3\u91ca：return\u662f\u2f00\u79cd\u66f4\u5e38\u2ec5\u7684\u9000\u51fa\u8fdb\u7a0b\u2f45\u6cd5\u3002\u6267\u2f8freturn num\u7b49\u540c\u4e8e\u6267\u2f8fexit(n)，\u56e0\u4e3a\u8c03\u2f64main\u7684\u8fd0\u2f8f\u65f6\u51fd\u6570\u4f1a\u5c06main\u7684\u8fd4\u56de\u503c\u5f53\u505a exit \u7684\u53c2\u6570\u3002\u53e6\u5916，\u53ea\u6709main\u51fd\u6570\u6267\u884c return \u8bed\u53e5\u624d\u4f1a\u7ed3\u675f\u8fdb\u7a0b，\u5176\u4ed6\u51fd\u6570\u6267\u884c return \u8bed\u53e5\u53ea\u662f\u7ed3\u675f\u5f53\u524d\u51fd\u6570\u800c\u5df2\u3002<\/p>\n #<\/span>include<\/span><sys\/types.h><\/span><\/p>\n #<\/span>include<\/span><sys\/wait.h><\/span><\/p>\n pid_t<\/span> wait<\/span>(int<\/span>* status);<\/p>\n<\/p>\n \u8fd4\u56de\u503c：<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u6210\u529f\u8fd4\u56de\u88ab\u7b49\u5f85\u8fdb\u7a0bpid，\u5931\u8d25\u8fd4\u56de-1\u3002<\/p>\n \u53c2\u6570：<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u8f93\u51fa\u578b\u53c2\u6570，\u83b7\u53d6\u2f26\u8fdb\u7a0b\u9000\u51fa\u72b6\u6001,\u4e0d\u5173\u2f3c\u5219\u53ef\u4ee5\u8bbe\u7f6e\u6210\u4e3aNULL\u3002<\/p>\n \u793a\u4f8b\u4ee3\u7801：<\/p>\n 1 #include<stdio.h> \u6548\u679c：<\/p>\n pid_ t waitpid<\/span>(pid_t<\/span> pid, int<\/span> *status, int <\/span>options);<\/p>\n \u8fd4\u56de\u503c：<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u5f53\u6b63\u5e38\u8fd4\u56de\u7684\u65f6\u5019waitpid\u8fd4\u56de\u6536\u96c6\u5230\u7684\u2f26\u8fdb\u7a0b\u7684\u8fdb\u7a0bID；<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u5982\u679c\u8bbe\u7f6e\u4e86\u9009\u9879WNOHANG,\u2f7d\u8c03\u2f64\u4e2dwaitpid\u53d1\u73b0\u6ca1\u6709\u5df2\u9000\u51fa\u7684\u2f26\u8fdb\u7a0b\u53ef\u6536\u96c6,\u5219\u8fd4\u56de0；<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u5982\u679c\u8c03\u2f64\u4e2d\u51fa\u9519,\u5219\u8fd4\u56de-1,\u8fd9\u65f6errno\u4f1a\u88ab\u8bbe\u7f6e\u6210\u76f8\u5e94\u7684\u503c\u4ee5\u6307\u2f70\u9519\u8bef\u6240\u5728；<\/p>\n \u53c2\u6570：<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0pid：<\/p>\n \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 pid=-1,\u7b49\u5f85\u4efb\u2f00\u4e2a\u2f26\u8fdb\u7a0b\u3002\u4e0ewait\u7b49\u6548\u3002<\/p>\n \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 pid>0.\u7b49\u5f85\u5176\u8fdb\u7a0bID\u4e0epid\u76f8\u7b49\u7684\u2f26\u8fdb\u7a0b\u3002<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0status: \u8f93\u51fa\u578b\u53c2\u6570<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0WIFEXITED(status): \u82e5\u4e3a\u6b63\u5e38\u7ec8\u2f4c\u2f26\u8fdb\u7a0b\u8fd4\u56de\u7684\u72b6\u6001，\u5219\u4e3a\u771f\u3002（\u67e5\u770b\u8fdb\u7a0b\u662f\u5426\u662f\u6b63\u5e38\u9000\u51fa）<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0WEXITSTATUS(status): \u82e5WIFEXITED\u2fae\u96f6，\u63d0\u53d6\u2f26\u8fdb\u7a0b\u9000\u51fa\u7801\u3002（\u67e5\u770b\u8fdb\u7a0b\u7684\u9000\u51fa\u7801）<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0options:\u9ed8\u8ba4\u4e3a0，\u8868\u2f70\u963b\u585e\u7b49\u5f85\u3002<\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0WNOHANG: \u82e5pid\u6307\u5b9a\u7684\u2f26\u8fdb\u7a0b\u6ca1\u6709\u7ed3\u675f，\u5219waitpid()\u51fd\u6570\u8fd4\u56de0，\u4e0d\u4e88\u4ee5\u7b49\u5f85\u3002\u82e5\u6b63\u5e38\u7ed3\u675f，\u5219\u8fd4\u56de\u8be5\u2f26\u8fdb\u7a0b\u7684ID\u3002<\/p>\n \u793a\u4f8b\u4ee3\u7801：<\/p>\n 1 #include<stdio.h> \u6548\u679c：<\/p>\n wait\u548cwaitpid，\u90fd\u6709\u2f00\u4e2astatus\u53c2\u6570，\u8be5\u53c2\u6570\u662f\u2f00\u4e2a\u8f93\u51fa\u578b\u53c2\u6570，\u7531\u64cd\u4f5c\u7cfb\u7edf\u586b\u5145\u3002<\/p>\n \u5982\u679c\u4f20\u9012NULL，\u8868\u2f70\u4e0d\u5173\u2f3c\u2f26\u8fdb\u7a0b\u7684\u9000\u51fa\u72b6\u6001\u4fe1\u606f\u3002<\/p>\n \u5426\u5219，\u64cd\u4f5c\u7cfb\u7edf\u4f1a\u6839\u636e\u8be5\u53c2\u6570，\u5c06\u2f26\u8fdb\u7a0b\u7684\u9000\u51fa\u4fe1\u606f\u53cd\u9988\u7ed9\u2f57\u8fdb\u7a0b\u3002<\/p>\n status\u4e0d\u80fd\u7b80\u5355\u7684\u5f53\u4f5c\u6574\u5f62\u6765\u770b\u5f85，\u53ef\u4ee5\u5f53\u4f5c\u4f4d\u56fe\u6765\u770b\u5f85，\u5177\u4f53\u7ec6\u8282\u5982\u4e0b\u56fe（\u53ea\u7814\u7a76status\u4f4e16 \u2f50\u7279\u4f4d）：<\/p>\n \u5728 status \u7684\u4f4e\u5341\u516d\u4f4d\u4e2d，\u6b21\u4f4e\u516b\u4f4d\u662f\u9000\u51fa\u7801，\u6b21\u4f4e\u4e03\u4f4d\u662f\u9000\u51fa\u4fe1\u53f7\u7684\u503c\u3002<\/p>\n \u793a\u4f8b\u4ee3\u7801：<\/p>\n 1 #include<stdio.h> \u6548\u679c：<\/p>\n \u793a\u4f8b\u4ee3\u7801：<\/p>\n #include <iostream> enum{ const std::string gsep = " "; int SaveBegin() std::string dataStr; void Save() int main() if(cnt % 10 == 0) \u5982\u679c\u6211\u4eec\u60f3\u8ba9\u7236\u8fdb\u7a0b\u5728\u7b49\u5f85\u5b50\u8fdb\u7a0b\u7684\u540c\u65f6\u8fd8\u53ef\u4ee5\u505a\u81ea\u5df1\u7684\u4e8b，\u4e0d\u88ab\u963b\u585e\u4f4f，\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u5c06waitpid\u65b9\u6cd5\u7684\u7b2c\u4e09\u4e2a\u53c2\u6570\u4f20\u5165WNOHANG，\u5373\u53ef\u8fdb\u5165\u975e\u963b\u585e\u7b49\u5f85\u6a21\u5f0f\u3002\u8be5\u65b9\u6cd5\u8fd4\u56de\u503c > 0 \u65f6，\u7b49\u5f85\u6210\u529f，\u8fd4\u56de\u503c\u4e3a\u76ee\u6807\u5b50\u8fdb\u7a0b\u7684pid；\u5f53\u8fd4\u56de\u503c == 0 \u65f6，\u7b49\u5f85\u6210\u529f，\u4f46\u662f\u76ee\u6807\u5b50\u8fdb\u7a0b\u6ca1\u6709\u9000\u51fa，\u8fd4\u56de\u503c< 0 \u65f6，\u7b49\u5f85\u5931\u8d25\u3002<\/p>\n \u793a\u4f8b\u4ee3\u7801：<\/p>\n task.h:<\/p>\n #pragma once void PrintLog(); task.cc:<\/p>\n #include "task.h"<\/p>\n void PrintLog() void Download() void Backup() proc.cc<\/p>\n #include <iostream> typedef std::function<void()> task_t;<\/p>\n void LoadTask(std::vector<task_t> &tasks) int main() pid_t id = fork(); \/\/ father \/\/ \u505a\u81ea\u5df1\u7684\u4e8b\u60c5 } <\/p>\n Makefile:<\/p>\n process:process.cc task.cc .PHONY:clean \u8fd9\u662f\u56e0\u4e3a\u5982\u679c\u6211\u4eec\u4f7f\u7528\u5168\u5c40\u53d8\u91cf\u6765\u83b7\u53d6，\u5b50\u8fdb\u7a0b\u548c\u7236\u8fdb\u7a0b\u7684\u6570\u636e\u5728\u4e0d\u4fee\u6539\u65f6\u662f\u5171\u4eab\u7684，\u4f46\u662f\u4e00\u65e6\u4fee\u6539\u5c31\u4f1a\u53d1\u751f\u5199\u5b9e\u62f7\u8d1d，\u8fd9\u5c31\u5bfc\u81f4\u7236\u8fdb\u7a0b\u62ff\u4e0d\u5230\u4fee\u6539\u540e\u7684\u503c，\u53ef\u5b50\u8fdb\u7a0b\u8981\u60f3\u901a\u8fc7\u53d8\u91cf\u5c06\u9000\u51fa\u7801\u4f20\u9012\u51fa\u53bb，\u5c31\u5fc5\u987b\u5bf9\u53d8\u91cf\u8fdb\u884c\u4fee\u6539，\u6240\u4ee5\u901a\u8fc7\u53d8\u91cf\u7684\u65b9\u5f0f\u884c\u4e0d\u901a，\u5c31\u53ea\u80fd\u901a\u8fc7\u7cfb\u7edf\u63d0\u4f9b\u7684\u63a5\u53e3\u4e86\u3002<\/p>\n fork() \u4e4b\u540e,\u2f57\u2f26\u5404\u2f83\u6267\u2f8f\u2f57\u8fdb\u7a0b\u4ee3\u7801\u7684\u2f00\u90e8\u5206\u5982\u679c\u2f26\u8fdb\u7a0b\u5c31\u60f3\u6267\u2f8f\u2f00\u4e2a\u5168\u65b0\u7684\u7a0b\u5e8f\u5462？\u8fdb\u7a0b\u7684\u7a0b\u5e8f \u66ff\u6362\u6765\u5b8c\u6210\u8fd9\u4e2a\u529f\u80fd！\u7a0b\u5e8f\u66ff\u6362\u662f\u901a\u8fc7\u7279\u5b9a\u7684\u63a5\u2f1d，\u52a0\u8f7d\u78c1\u76d8\u4e0a\u7684\u2f00\u4e2a\u5168\u65b0\u7684\u7a0b\u5e8f(\u4ee3\u7801\u548c\u6570\u636e)，\u52a0\u8f7d\u5230\u8c03\u2f64\u8fdb\u7a0b\u7684\u5730\u5740\u7a7a\u95f4\u4e2d！<\/p>\n \u2f64fork\u521b\u5efa\u2f26\u8fdb\u7a0b\u540e\u6267\u2f8f\u7684\u662f\u548c\u2f57\u8fdb\u7a0b\u76f8\u540c\u7684\u7a0b\u5e8f(\u4f46\u6709\u53ef\u80fd\u6267\u2f8f\u4e0d\u540c\u7684\u4ee3\u7801\u5206\u2f40),\u2f26\u8fdb\u7a0b\u5f80\u5f80\u8981\u8c03\u2f64\u2f00\u79cdexec\u51fd\u6570\u4ee5\u6267\u2f8f\u53e6\u2f00\u4e2a\u7a0b\u5e8f\u3002\u5f53\u8fdb\u7a0b\u8c03\u2f64\u2f00\u79cdexec\u51fd\u6570\u65f6,\u8be5\u8fdb\u7a0b\u7684\u7528\u6237\u7a7a\u95f4\u4ee3\u7801\u548c\u6570\u636e\u5b8c\u5168\u88ab\u65b0\u7a0b\u5e8f\u66ff\u6362,\u4ece\u65b0\u7a0b\u5e8f\u7684\u542f\u52a8\u4f8b\u7a0b\u5f00\u59cb\u6267\u2f8f\u3002\u8c03\u2f64exec\u5e76\u4e0d\u521b\u5efa\u65b0\u8fdb\u7a0b,\u6240\u4ee5\u8c03\u2f64exec\u524d\u540e\u8be5\u8fdb\u7a0b\u7684id\u5e76\u672a\u6539\u53d8\u3002<\/p>\n \u5176\u5b9e\u6709\u516d\u79cd\u4ee5exec\u5f00\u5934\u7684\u51fd\u6570,\u7edf\u79f0exec\u51fd\u6570:<\/p>\n #<\/span>include<\/span><unistd.h><\/span><\/p>\n<\/p>\n int<\/span> execl<\/span>(const char<\/span> *path, const char<\/span> *arg, …);<\/p>\n int <\/span>execlp<\/span>(const char<\/span> *file, const char<\/span> *arg, …);<\/p>\n int<\/span> execle<\/span>(const char <\/span>*path, const char<\/span> *arg, …,char<\/span> *const<\/span> envp[]);<\/p>\n int <\/span>execv<\/span>(const char <\/span>*path, char<\/span> *const<\/span> argv[]);<\/p>\n int<\/span> execvp<\/span>(const char <\/span>*file, char <\/span>*const <\/span>argv[]);<\/p>\n int<\/span> execve<\/span>(const char<\/span> *path, char <\/span>*const<\/span> argv[], char<\/span> *const <\/span>envp[]);<\/p>\n \u8fd9\u4e9b\u51fd\u6570\u539f\u578b\u770b\u8d77\u6765\u5f88\u5bb9\u6613\u6df7,\u4f46\u53ea\u8981\u638c\u63e1\u4e86\u89c4\u5f8b\u5c31\u5f88\u597d\u8bb0\u3002<\/p>\n exec\u8c03\u2f64\u4e3e\u4f8b\u5982\u4e0b:<\/span><\/p>\n \u4e3a\u4e86\u65b9\u4fbf\u6f14\u793a，\u6240\u6709exec\u8c03\u7528\u90fd\u653e\u5230\u4e86\u4e00\u4e2a\u7a0b\u5e8f\u4e2d\u4e86，\u5b9e\u9645\u4f7f\u7528\u65f6\u4e00\u4e2a\u5b50\u8fdb\u7a0b\u6839\u636e\u9700\u8981\u6267\u884c\u67d0\u4e00\u4e2a\u5c31\u53ef\u4ee5\u3002<\/span><\/p>\n myexec.cc:<\/p>\n 1 #include <iostream> other.c:<\/p>\n #include <stdio.h><\/p>\n extern char**environ;<\/p>\n int main() test.py:<\/p>\n #!\/usr\/bin\/python<\/p>\n print ("hello python")<\/p>\n test.sh:<\/p>\n #!\/bin\/bash<\/p>\n echo "hello shell"<\/p>\n Makefile:<\/p>\n myexec:myexec.cc .PHONY:clean \u4e8b\u5b9e\u4e0a,\u53ea\u6709execve\u662f\u771f\u6b63\u7684\u7cfb\u7edf\u8c03\u2f64,\u5176\u5b83\u4e94\u4e2a\u51fd\u6570\u6700\u7ec8\u90fd\u8c03\u2f64execve,\u6240\u4ee5execve\u5728man\u2f3f\u518c\u7b2c2\u8282, \u5176\u5b83\u51fd\u6570\u5728man\u2f3f\u518c\u7b2c3\u8282\u3002\u8fd9\u4e9b\u51fd\u6570\u4e4b\u95f4\u7684\u5173\u7cfb\u5982\u4e0b\u56fe\u6240\u2f70\u3002\u4e0b\u56feexec\u51fd\u6570\u7c07\u2f00\u4e2a\u5b8c\u6574\u7684\u4f8b\u2f26：<\/p>\n \u2f64\u4e0b\u56fe\u7684\u65f6\u95f4\u8f74\u6765\u8868\u2f70\u4e8b\u4ef6\u7684\u53d1\u2f63\u6b21\u5e8f\u3002\u5176\u4e2d\u65f6\u95f4\u4ece\u5de6\u5411\u53f3\u3002shell\u7531\u6807\u8bc6\u4e3ash\u7684\u2f45\u5757\u4ee3\u8868，\u5b83\u968f\u7740\u65f6\u95f4\u7684\u6d41\u901d\u4ece\u5de6\u5411\u53f3\u79fb\u52a8\u3002shell\u4ece\u7528\u6237\u8bfb\u2f0a\u5b57\u7b26\u4e32"ls"\u3002shell\u5efa\u2f74\u2f00\u4e2a\u65b0\u7684\u8fdb\u7a0b，\u7136\u540e\u5728\u90a3\u4e2a\u8fdb\u7a0b\u4e2d\u8fd0\u2f8fls\u7a0b\u5e8f\u5e76\u7b49\u5f85\u90a3\u4e2a\u8fdb\u7a0b\u7ed3\u675f\u3002<\/p>\n \u7136\u540eshell\u8bfb\u53d6\u65b0\u7684\u2f00\u2f8f\u8f93\u2f0a，\u5efa\u2f74\u2f00\u4e2a\u65b0\u7684\u8fdb\u7a0b，\u5728\u8fd9\u4e2a\u8fdb\u7a0b\u4e2d\u8fd0\u2f8f\u7a0b\u5e8f\u5e76\u7b49\u5f85\u8fd9\u4e2a\u8fdb\u7a0b\u7ed3\u675f\u3002\u00a0\u6240\u4ee5\u8981\u5199\u2f00\u4e2ashell，\u9700\u8981\u5faa\u73af\u4ee5\u4e0b\u8fc7\u7a0b:<\/p>\n \u6839\u636e\u8fd9\u4e9b\u601d\u8def，\u548c\u6211\u4eec\u524d\u2faf\u7684\u5b66\u7684\u6280\u672f，\u5c31\u53ef\u4ee5\u2f83\u2f30\u6765\u5b9e\u73b0\u2f00\u4e2ashell\u4e86\u3002<\/p>\n #include <iostream> using namespace std;<\/p>\n const int basesize = 1024; \/\/ \u5168\u5c40\u7684\u53d8\u91cf \/\/ \u6211\u7684\u7cfb\u7edf\u7684\u73af\u5883\u53d8\u91cf \/\/ \u5168\u5c40\u7684\u5f53\u524dshell\u5de5\u4f5c\u8def\u5f84 string GetUserName() string GetHostName() string GetPwd() \/\/string pwd = getenv("PWD"); string LastDir() string MakeCommandLine() void PrintCommandLine() \/\/ 1. \u547d\u4ee4\u884c\u63d0\u793a\u7b26 bool GetCommandLine(char command_buffer[], int size) \/\/ 2. \u83b7\u53d6\u7528\u6237\u547d\u4ee4 void ParseCommandLine(char command_buffer[], int len) \/\/ 3. \u5206\u6790\u547d\u4ee4 void debug() void AddEnv(const char *item) genv[index] = (char*)malloc(strlen(item)+1); \/\/ \u4f5c\u4e3a\u4e00\u4e2ashell，\u83b7\u53d6\u73af\u5883\u53d8\u91cf\u5e94\u8be5\u4ece\u7cfb\u7edf\u7684\u914d\u7f6e\u6765 int main() if ( CheckAndExecBuiltCommand() ) ExecuteCommand(); \/\/ 4. \u6267\u884c\u547d\u4ee4 exec\/exit\u5c31\u50cfcall\/return\u3002<\/p>\n \u00a0\u2f00\u4e2aC\u7a0b\u5e8f\u6709\u5f88\u591a\u51fd\u6570\u7ec4\u6210\u3002\u2f00\u4e2a\u51fd\u6570\u53ef\u4ee5\u8c03\u2f64\u53e6\u5916\u2f00\u4e2a\u51fd\u6570，\u540c\u65f6\u4f20\u9012\u7ed9\u5b83\u2f00\u4e9b\u53c2\u6570\u3002\u88ab\u8c03\u2f64\u7684\u51fd\u6570\u6267\u2f8f\u2f00\u5b9a\u7684\u64cd\u4f5c，\u7136\u540e\u8fd4\u56de\u2f00\u4e2a\u503c\u3002\u6bcf\u4e2a\u51fd\u6570\u90fd\u6709\u4ed6\u7684\u5c40\u90e8\u53d8\u91cf，\u4e0d\u540c\u7684\u51fd\u6570\u901a\u8fc7call\/return\u7cfb\u7edf\u8fdb\u2f8f\u901a\u4fe1\u3002<\/p>\n \u8fd9\u79cd\u901a\u8fc7\u53c2\u6570\u548c\u8fd4\u56de\u503c\u5728\u62e5\u6709\u79c1\u6709\u6570\u636e\u7684\u51fd\u6570\u95f4\u901a\u4fe1\u7684\u6a21\u5f0f\u662f\u7ed3\u6784\u5316\u7a0b\u5e8f\u8bbe\u8ba1\u7684\u57fa\u7840\u3002Linux\u2fce\u52b1\u5c06\u8fd9\u79cd\u5e94\u2f64\u4e8e\u7a0b\u5e8f\u4e4b\u5185\u7684\u6a21\u5f0f\u6269\u5c55\u5230\u7a0b\u5e8f\u4e4b\u95f4\u3002\u5982\u4e0b\u56fe<\/p>\n \u2f00\u4e2aC\u7a0b\u5e8f\u53ef\u4ee5fork\/exec\u53e6\u2f00\u4e2a\u7a0b\u5e8f，\u5e76\u4f20\u7ed9\u5b83\u2f00\u4e9b\u53c2\u6570\u3002\u8fd9\u4e2a\u88ab\u8c03\u2f64\u7684\u7a0b\u5e8f\u6267\u2f8f\u2f00\u5b9a\u7684\u64cd\u4f5c，\u7136\u540e\u901a\u8fc7exit(n)\u6765\u8fd4\u56de\u503c\u3002\u8c03\u2f64\u5b83\u7684\u8fdb\u7a0b\u53ef\u4ee5\u901a\u8fc7wait（&ret）\u6765\u83b7\u53d6exit\u7684\u8fd4\u56de\u503c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":" \u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb1.1k\u6b21\uff0c\u70b9\u8d5e39\u6b21\uff0c\u6536\u85cf50\u6b21\u3002Linux\u4e4b\u8fdb\u7a0b\u63a7\u5236_linux\u8fdb\u7a0b\u7684\u521b\u5efa\u548c\u63a7\u5236<\/p>\n","protected":false},"author":2,"featured_media":37799,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[55,58,190,305,124],"topic":[],"class_list":["post-37819","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server","tag-c","tag-linux","tag-190","tag-305","tag-124"],"yoast_head":"\n\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094605-68285add2631c.png\")
<\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094605-68285add6115c.png\")
<\/p>\n1.2\u3001fork\u51fd\u6570\u8fd4\u56de\u503c<\/h3>\n
\n
1.3\u3001\u5199\u5b9e\u62f7\u8d1d<\/h3>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094605-68285add9480e.png\")
<\/p>\n1.4\u3001fork\u5e38\u89c4\u7528\u6cd5<\/h3>\n
\n
1.5\u3001fork\u8c03\u7528\u5931\u8d25\u7684\u539f\u56e0<\/h3>\n
\n
\u4e8c\u3001\u8fdb\u7a0b\u7ec8\u6b62<\/h2>\n
2.1\u3001\u8fdb\u7a0b\u9000\u51fa\u573a\u666f<\/h3>\n
\n
\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094605-68285addcb85f.png\")
<\/p>\n2.2\u3001\u8fdb\u7a0b\u5e38\u89c1\u9000\u51fa\u65b9\u6cd5<\/h3>\n
\n
\n
2.2.1\u3001\u9000\u51fa\u7801<\/h4>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285ade0d30d.png\")
<\/p>\n\n
\n 2 #include<string>
\n 3 #include<cstdio>
\n 4 #include<string.h>
\n 5 #include<error.h>
\n 6
\n 7 int main()
\n 8 {
\n 9 printf("before: errno: %d, errstring: %s\\\\n",errno,strerror(errno));
\n 10
\n 11 FILE *fp = fopen("log.txt","r");
\n 12 if(fp == nullptr)
\n 13 {
\n 14 printf("after: errno: %d, errstring: %s\\\\n",errno,strerror(errno));
\n 15 return errno;
\n 16 }
\n 17
\n 18 return 0;
\n 19 } <\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285ade47e1a.png\")
<\/p>\n2.3.2\u3001_exit\u51fd\u6570<\/h4>\n
\n 2 #include<string>
\n 3 #include<cstdio>
\n 4 #include<string.h>
\n 5 #include<unistd.h>
\n 6
\n 7 void func()
\n 8 {
\n 9 std::cout<<"hello,bit"<<std::endl;
\n 10
\n 11 _exit(10);
\n 12 }
\n 13
\n 14 int main()
\n 15 {
\n 16 func();
\n 17 std::cout<<"\u8fdb\u7a0b\u7ed3\u675f\u4e86"<<std::endl;
\n 18
\n 19 return 0;
\n 20 } <\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285ade5a2bb.png\")
<\/p>\n
\n#include <unistd.h>
\n#include<stdlib.h><\/p>\n
\n{
\n printf("\u8fdb\u7a0b\u8fd0\u884c\u7ed3\u675f!\\\\n");
\n sleep(2);
\n _exit(20);<\/p>\n
\n} <\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285ade6d7bd.png\")
<\/p>\n2.3.3\u3001exit\u51fd\u6570<\/h4>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285ade7e82f.png\")
<\/p>\n
\n 2 #include<string>
\n 3 #include<cstdio>
\n 4 #include<string.h>
\n 5 #include<unistd.h>
\n 6
\n 7 void func()
\n 8 {
\n 9 std::cout<<"hello,bit"<<std::endl;
\n 10
\n 11 exit(10);
\n 12 }
\n 13
\n 14 int main()
\n 15 {
\n 16 func();
\n 17 std::cout<<"\u8fdb\u7a0b\u7ed3\u675f\u4e86"<<std::endl;
\n 18
\n 19 return 0;
\n 20 } <\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285adeb5d8f.png\")
<\/p>\n
\n#include <unistd.h>
\n#include<stdlib.h><\/p>\n
\n{
\n printf("\u8fdb\u7a0b\u8fd0\u884c\u7ed3\u675f!\\\\n");
\n sleep(2);
\n exit(20);<\/p>\n
\n}<\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285adec7281.png\")
<\/p>\n2.3.4\u3001return\u9000\u51fa<\/h4>\n
\n 2 #include<string>
\n 3 #include<cstdio>
\n 4 #include<string.h>
\n 5 #include<unistd.h>
\n 6
\n 7 int func()
\n 8 {
\n 9 std::cout<<"hello,bit"<<std::endl;
\n 10
\n 11 return 10;
\n 12 }
\n 13
\n 14 int main()
\n 15 {
\n 16 func();
\n 17 std::cout<<"\u8fdb\u7a0b\u7ed3\u675f\u4e86"<<std::endl;
\n 18
\n 19 return 0;
\n 20 } <\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285aded7ed6.png\")
<\/p>\n\u4e09\u3001\u8fdb\u7a0b\u7b49\u5f85<\/h2>\n
3.1\u3001\u8fdb\u7a0b\u7b49\u5f85\u5fc5\u8981\u6027<\/h3>\n
\n
3.2\u3001\u8fdb\u7a0b\u7b49\u5f85\u7684\u65b9\u6cd5<\/h3>\n
3.2.1\u3001wait\u65b9\u6cd5<\/h4>\n
\n 2 #include<unistd.h>
\n 3 #include<errno.h>
\n 4 #include<string.h>
\n 5 #include<stdlib.h>
\n 6 #include<sys\/wait.h>
\n 7
\n 8 int main()
\n 9 {
\n 10 pid_t id = fork();
\n 11 if(id < 0)
\n 12 {
\n 13 printf("errno: %d,errstring: %s\\\\n",errno,strerror(errno));
\n 14 return errno;
\n 15 }
\n 16 else if(id == 0)
\n 17 {
\n 18 int cnt = 3;
\n 19 while(cnt)
\n 20 {
\n 21 printf("\u5b50\u8fdb\u7a0b\u8fd0\u884c\u4e2d，pid：%d\\\\n",getpid());
\n 22 cnt–;
\n 23 sleep(1);
\n 24 }
\n 25 exit(123);
\n 26 }
\n 27 else
\n 28 {
\n 29 sleep(5);
\n 30 pid_t rid = wait(nullptr);
\n 31 if(rid > 0)
\n 32 {
\n 33 printf("wait sub process success,rid: %d\\\\n",rid);
\n 34 }
\n 35 else
\n 36 {
\n 37 perror("wait fail:");
\n 38 }
\n 39 while(true)
\n 40 {
\n 41 printf("\u6211\u662f\u7236\u8fdb\u7a0b,pid: %d\\\\n",getpid());
\n 42 sleep(1);
\n 43 }
\n 44 }
\n 45
\n 46 return 0;
\n 47 }<\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094606-68285adeeb981.png\")
<\/p>\n3.2.2\u3001waitpid\u65b9\u6cd5<\/h4>\n
\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094607-68285adf0ff48.png\")
<\/p>\n
\n 2 #include<unistd.h>
\n 3 #include<errno.h>
\n 4 #include<string.h>
\n 5 #include<stdlib.h>
\n 6 #include<sys\/wait.h>
\n 7
\n 8 int main()
\n 9 {
\n 10 pid_t id = fork();
\n 11 if(id < 0)
\n 12 {
\n 13 printf("errno: %d,errstring: %s\\\\n",errno,strerror(errno));
\n 14 return errno;
\n 15 }
\n 16 else if(id == 0)
\n 17 {
\n 18 int cnt = 3;
\n 19 while(cnt)
\n 20 {
\n 21 printf("\u5b50\u8fdb\u7a0b\u8fd0\u884c\u4e2d，pid：%d\\\\n",getpid());
\n 22 cnt–;
\n 23 sleep(1);
\n 24 }
\n 25 exit(123);
\n 26 }
\n 27 else
\n 28 {
\n 29 sleep(5);
\n 30 pid_t rid = waitpid(id,nullptr,0);
\n 31 if(rid > 0)
\n 32 {
\n 33 printf("wait sub process success,rid: %d\\\\n",rid);
\n 34 }
\n 35 else
\n 36 {
\n 37 perror("wait fail:");
\n 38 }
\n 39 while(true)
\n 40 {
\n 41 printf("\u6211\u662f\u7236\u8fdb\u7a0b,pid: %d\\\\n",getpid());
\n 42 sleep(1);
\n 43 }
\n 44 }
\n 45
\n 46 return 0;
\n 47 } <\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094607-68285adf50ac6.png\")
<\/p>\n3.2.3\u3001\u83b7\u53d6\u5b50\u8fdb\u7a0bstatus<\/h4>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094607-68285adf739fe.png\")
<\/p>\n
\n 2 #include<unistd.h>
\n 3 #include<errno.h>
\n 4 #include<string.h>
\n 5 #include<stdlib.h>
\n 6 #include<sys\/wait.h>
\n 7
\n 8 int main()
\n 9 {
\n 10 pid_t id = fork();
\n 11 if(id < 0)
\n 12 {
\n 13 printf("errno: %d,errstring: %s\\\\n",errno,strerror(errno));
\n 14 return errno;
\n 15 }
\n 16 else if(id == 0)
\n 17 {
\n 18 int cnt = 3;
\n 19 while(cnt)
\n 20 {
\n 21 printf("\u5b50\u8fdb\u7a0b\u8fd0\u884c\u4e2d，pid：%d\\\\n",getpid());
\n 22 cnt–;
\n 23 sleep(1);
\n 24 }
\n 25 exit(123);
\n 26 }
\n 27 else
\n 28 {
\n 29 sleep(5);
\n 30
\n 31 int status = 0;
\n 32 pid_t rid = waitpid(id, &status, 0);
\n 33
\n 34 if(rid > 0)
\n 35 {
\n 36 if(WIFEXITED(status))
\n 37 {
\n 38 \/\/\u4e24\u79cd\u83b7\u53d6\u9000\u51fa\u7801\u7684\u65b9\u6cd5，\u7b2c\u4e00\u79cd\u8fd8\u53ef\u4ee5\u83b7\u53d6\u9000\u51fa\u4fe1\u53f7
\n 39 printf("wait sub process success,rid: %d, status code: %d, exit signal: %d\\\\n", rid, (status>>8)&0xFF, status&0x7F);
\n 40
\n 41 printf("wait sub process success,rid: %d, status code: %d\\\\n", rid, WEXITSTATUS(status));
\n 42 }
\n 43 else
\n 44 {
\n 45 printf("child process quit error!\\\\n");
\n 46 }
\n 47 }
\n 48 else
\n 49 {
\n 50 perror("wait fail:");
\n 51 }
\n 52
\n 53 while(true)
\n 54 {
\n 55 printf("\u6211\u662f\u7236\u8fdb\u7a0b,pid: %d\\\\n",getpid());
\n 56 sleep(1);
\n 57 }
\n 58 }
\n 59
\n 60 return 0;
\n 61 }<\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094607-68285adf974a9.png\")
<\/p>\n3.2.4\u3001\u963b\u585e\u4e0e\u975e\u963b\u585e\u7b49\u5f85<\/h4>\n
\n
\n#include <vector>
\n#include <cstdio>
\n#include <unistd.h>
\n#include <sys\/types.h>
\n#include <sys\/wait.h>
\n#include <functional>
\n#include "task.h"<\/p>\n
\n OK = 0,
\n OPEN_FILE_ERROR,
\n};<\/p>\n
\nstd::vector<int> data;<\/p>\n
\n{
\n std::string name = std::to_string(time(nullptr));
\n name += ".backup";
\n FILE *fp = fopen(name.c_str(), "w");
\n if(fp == nullptr) return OPEN_FILE_ERROR;<\/p>\n
\n for (auto d : data)
\n {
\n dataStr += std::to_string(d);
\n dataStr += gsep;
\n }
\n fputs(dataStr.c_str(), fp);
\n fclose(fp);
\n return OK;
\n}<\/p>\n
\n{
\n pid_t id = fork();
\n if(id == 0) \/\/ \u5b50\u8fdb\u7a0b
\n {
\n int code = SaveBegin();
\n exit(code);
\n }
\n int status = 0;
\n pid_t rid = waitpid(id, &status, 0);
\n if(rid > 0)
\n {
\n int code = WEXITSTATUS(status);
\n if(code == 0) printf("\u5907\u4efd\u6210\u529f, exit code : %d\\\\n", code);
\n else printf("\u5907\u4efd\u5931\u8d25, exit code : %d\\\\n", code);
\n }
\n else
\n {
\n perror("waitpid");
\n }
\n}<\/p>\n
\n{
\n int cnt = 1;
\n while(true)
\n {
\n data.push_back(cnt++);
\n sleep(1);<\/p>\n
\n {
\n Save();
\n }
\n }
\n}<\/p>\n\n
\n#include <iostream><\/p>\n
\nvoid Download();
\nvoid Backup();<\/p>\n
\n{
\n std::cout << "Print log task" << std::endl;
\n}<\/p>\n
\n{
\n std::cout << "DownLoad task" << std::endl;
\n}<\/p>\n
\n{
\n std::cout << "BackUp task" << std::endl;
\n}<\/p>\n
\n#include <vector>
\n#include <cstdio>
\n#include <unistd.h>
\n#include <sys\/types.h>
\n#include <sys\/wait.h>
\n#include <functional>
\n#include "task.h"<\/p>\n
\n{
\n tasks.push_back(PrintLog);
\n tasks.push_back(Download);
\n tasks.push_back(Backup);
\n}<\/p>\n
\n{
\n std::vector<task_t> tasks;
\n LoadTask(tasks);<\/p>\n
\n if(id == 0)
\n {
\n \/\/ child
\n while(true)
\n {
\n printf("\u6211\u662f\u5b50\u8fdb\u7a0b, pid : %d\\\\n", getpid());
\n sleep(1);
\n }
\n exit(0);
\n }<\/p>\n
\n while(true)
\n {
\n sleep(1);
\n pid_t rid = waitpid(id, nullptr, WNOHANG);
\n if(rid > 0)
\n {
\n printf("\u7b49\u5f85\u5b50\u8fdb\u7a0b%d \u6210\u529f\\\\n", rid);
\n break;
\n }
\n else if(rid < 0)
\n {
\n printf("\u7b49\u5f85\u5b50\u8fdb\u7a0b\u5931\u8d25\\\\n");
\n break;
\n }
\n else
\n {
\n printf("\u5b50\u8fdb\u7a0b\u5c1a\u672a\u9000\u51fa\\\\n");<\/p>\n
\n for(auto &task : tasks)
\n {
\n task();
\n }
\n }
\n }<\/p>\n
\ng++ -o $@ $^ -std=c++11<\/p>\n
\nclean:
\nrm -f process<\/p>\n3.2.5\u3001\u4e3a\u4ec0\u4e48\u8981\u901a\u8fc7\u7cfb\u7edf\u8c03\u7528\u6765\u83b7\u53d6\u8fdb\u7a0b\u9000\u51fa\u7801<\/h4>\n
\u56db\u3001\u8fdb\u7a0b\u7a0b\u5e8f\u66ff\u6362<\/h2>\n
4.1\u3001\u66ff\u6362\u539f\u7406<\/h3>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094607-68285adfc0237.png\")
<\/p>\n4.2\u3001\u66ff\u6362\u51fd\u6570<\/h3>\n
4.2.1\u3001\u51fd\u6570\u89e3\u91ca<\/h4>\n
\n
4.2.2\u3001\u547d\u540d\u7406\u89e3<\/h4>\n
\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094608-68285ae00309a.png\")
<\/p>\n
\n 2 #include <cstdio>
\n 3 #include <unistd.h>
\n 4 #include <sys\/types.h>
\n 5 #include <sys\/wait.h>
\n 6
\n 7 const std::string myenv="HELLO=AAAAAAAAAAAAAAAAAAAA";
\n 8
\n 9 extern char **environ;
\n 10 int main()
\n 11 {
\n 12 \/\/\u5728\u539f\u6709\u73af\u5883\u53d8\u91cf\u4e0a\u589e\u52a0\u65b0\u7684
\n 13 putenv((char*)myenv.c_str());
\n 14
\n 15 pid_t id = fork();
\n 16
\n 17 if(id == 0)
\n 18 {
\n 19 char *const argv[] = {
\n 20 (char*)"other",
\n 21 nullptr
\n 22 };
\n 23
\n 24 \/\/(void)argv;
\nW> 25 char *const env[] = {
\n 26 (char*)"HELLO=bite",
\n 27 (char*)"HELLO1=bite1",
\n 28 (char*)"HELLO2=bite2",
\n 29 (char*)"HELLO3=bite3"
\n 30 };
\n 31
\n 32 \/\/\u5141\u8bb8\u81ea\u5df1\u4f20\u5165\u73af\u5883\u53d8\u91cf
\n 33 \/\/ \u4f20\u5165\u7684\u4f1a\u8986\u76d6\u7ee7\u627f\u6765\u7684
\n 34 \/\/ \u8be5\u65b9\u6cd5\u4f1a\u4f7f\u7528\u4f20\u5165\u7684\u65b0\u7684\u73af\u5883\u53d8\u91cf
\n 35 \/\/ \u6211\u4eec\u53ef\u4ee5\u81ea\u5df1\u5199\u4e00\u4e2a\u5168\u65b0\u7684，\u4e5f\u53ef\u4ee5\u5728\u539f\u6709\u73af\u5883\u53d8\u91cf\u540e\u9762\u6dfb\u52a0\u65b0\u7684\u9879
\n 36 execvpe(".\/other", argv, environ);
\n 37
\n 38 \/\/\u53ef\u4ee5\u81ea\u52a8\u67e5\u627e\u73af\u5883\u53d8\u91cf，\u7b2c\u4e00\u4e2a\u53c2\u6570\u4e0d\u9700\u8981\u6307\u660e\u8def\u5f84
\n 39 execvp(argv[0], argv);
\n 40
\n 41 \/\/\u548cexecl\u4e00\u6837，\u53ea\u662f\u7b2c\u4e8c\u4e2a\u53c2\u6570\u53d8\u6210\u4e86\u6570\u7ec4
\n 42 execv("\/usr\/bin\/ls", argv);
\n 43
\n 44 \/\/ execl\u6700\u540e\u4e00\u4e2a\u53c2\u6570\u5fc5\u987b\u662fnullptr
\n 45 \/\/ \u7b2c\u4e00\u4e2a\u53c2\u6570\u4ee3\u8868\u8981\u6267\u884c\u8c01
\n 46 \/\/ \u540e\u9762\u7684\u53ef\u53d8\u53c2\u6570\u5217\u8868\u8868\u660e\u8981\u600e\u4e48\u6267\u884c
\n 47 execl("\/bin\/ls", "ls", "-l", "–color", "-a", nullptr);
\n 48 execl(".\/other", "other", nullptr);
\n 49 execl("\/usr\/bin\/python", "python", "test.py", nullptr);
\n 50 execl("\/usr\/bin\/bash", "bash", "test.sh", nullptr);
\n 51
\n 52 \/\/\u81ea\u52a8\u67e5\u627e\u73af\u5883\u53d8\u91cf，\u7b2c\u4e00\u4e2a\u53c2\u6570\u4e0d\u9700\u8981\u6307\u660e\u8def\u5f84
\n 53 execlp("ls", "ls", "–color", "-aln", nullptr);
\n 54
\n 55 \/\/\u5982\u679c\u7a0b\u5e8f\u66ff\u6362\u5931\u8d25，\u7ed3\u675f\u5b50\u8fdb\u7a0b\u8fd4\u56de\u9519\u8bef\u7801 -> 1
\n 56 exit(1);
\n 57 }
\n 58
\n 59 \/\/ father
\n 60 pid_t rid = waitpid(id, nullptr, 0);
\n 61 if(rid > 0)
\n 62 {
\n 63 printf("\u7b49\u5f85\u5b50\u8fdb\u7a0b\u6210\u529f!\\\\n");
\n 64 }
\n 65
\n 66 return 0;
\n 67 }<\/p>\n
\n{
\n for(int i = 0; environ[i]; i++)
\n {
\n printf("evn[%d]: %s\\\\n", i, environ[i]);
\n }
\n}<\/p>\n
\ng++ -o $@ $^ -std=c++11<\/p>\n
\nclean:
\nrm -f myexec<\/p>\n![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250517094608-68285ae0314f7.png\")
<\/p>\n\u4e94\u3001\u81ea\u4e3bShell\u547d\u4ee4\u884c\u89e3\u91ca\u5668<\/h2>\n
5.1\u3001\u76ee\u6807<\/h3>\n
\n
5.2\u3001\u5b9e\u73b0\u539f\u7406<\/h3>\n
![\"\"](\"2025-05-175rrmdsqazx5.png\")
<\/p>\n\n
5.3\u3001\u6e90\u7801<\/h3>\n
\n#include <cstdio>
\n#include <cstdlib>
\n#include <cstring>
\n#include <string>
\n#include <unistd.h>
\n#include <sys\/types.h>
\n#include <sys\/wait.h><\/p>\n
\nconst int argvnum = 64;
\nconst int envnum = 64;
\n\/\/ \u5168\u5c40\u7684\u547d\u4ee4\u884c\u53c2\u6570\u8868
\nchar *gargv[argvnum];
\nint gargc = 0;<\/p>\n
\nint lastcode = 0;<\/p>\n
\nchar *genv[envnum];<\/p>\n
\nchar pwd[basesize];
\nchar pwdenv[basesize];<\/p>\n
\n{
\n string name = getenv("USER");
\n return name.empty() ? "None" : name;
\n}<\/p>\n
\n{
\n string hostname = getenv("HOSTNAME");
\n return hostname.empty() ? "None" : hostname;
\n}<\/p>\n
\n{
\n if(nullptr == getcwd(pwd, sizeof(pwd))) return "None";
\n snprintf(pwdenv, sizeof(pwdenv),"PWD=%s", pwd);
\n putenv(pwdenv); \/\/ PWD=XXX
\n return pwd;<\/p>\n
\n \/\/return pwd.empty() ? "None" : pwd;
\n}<\/p>\n
\n{
\n string curr = GetPwd();
\n if(curr == "\/" || curr == "None") return curr;
\n \/\/ \/home\/whb\/XXX
\n size_t pos = curr.rfind("\/");
\n if(pos == std::string::npos) return curr;
\n return curr.substr(pos+1);
\n}<\/p>\n
\n{
\n \/\/ [whb@bite-alicloud myshell]$
\n char command_line[basesize];
\n snprintf(command_line, basesize, "[%s@%s %s]# ",\\\\
\n GetUserName().c_str(), GetHostName().c_str(), LastDir().c_str());
\n return command_line;
\n}<\/p>\n
\n{
\n printf("%s", MakeCommandLine().c_str());
\n fflush(stdout);
\n}<\/p>\n
\n{
\n \/\/ \u6211\u4eec\u8ba4\u4e3a：\u6211\u4eec\u8981\u5c06\u7528\u6237\u8f93\u5165\u7684\u547d\u4ee4\u884c，\u5f53\u505a\u4e00\u4e2a\u5b8c\u6574\u7684\u5b57\u7b26\u4e32
\n \/\/ "ls -a -l -n"
\n char *result = fgets(command_buffer, size, stdin);
\n if(!result)
\n {
\n return false;
\n }
\n command_buffer[strlen(command_buffer)-1] = 0;
\n if(strlen(command_buffer) == 0) return false;
\n return true;
\n}<\/p>\n
\n{
\n (void)len;
\n memset(gargv, 0, sizeof(gargv));
\n gargc = 0;
\n \/\/ "ls -a -l -n"
\n const char *sep = " ";
\n gargv[gargc++] = strtok(command_buffer, sep);
\n \/\/ =\u662f\u523b\u610f\u5199\u7684
\n while((bool)(gargv[gargc++] = strtok(nullptr, sep)));
\n gargc–;
\n}<\/p>\n
\n{
\n printf("argc: %d\\\\n", gargc);
\n for(int i = 0; gargv[i]; i++)
\n {
\n printf("argv[%d]: %s\\\\n", i, gargv[i]);
\n }
\n}
\n\/\/ \u5728shell\u4e2d
\n\/\/ \u6709\u4e9b\u547d\u4ee4，\u5fc5\u987b\u7531\u5b50\u8fdb\u7a0b\u6765\u6267\u884c
\n\/\/ \u6709\u4e9b\u547d\u4ee4，\u4e0d\u80fd\u7531\u5b50\u8fdb\u7a0b\u6267\u884c，\u8981\u7531shell\u81ea\u5df1\u6267\u884c — \u5185\u5efa\u547d\u4ee4 built command
\nbool ExecuteCommand() \/\/ 4. \u6267\u884c\u547d\u4ee4
\n{
\n \/\/ \u8ba9\u5b50\u8fdb\u7a0b\u8fdb\u884c\u6267\u884c
\n pid_t id = fork();
\n if(id < 0) return false;
\n if(id == 0)
\n {
\n \/\/\u5b50\u8fdb\u7a0b
\n \/\/ 1. \u6267\u884c\u547d\u4ee4
\n execvpe(gargv[0], gargv, genv);
\n \/\/ 2. \u9000\u51fa
\n exit(1);
\n }
\n int status = 0;
\n pid_t rid = waitpid(id, &status, 0);
\n if(rid > 0)
\n {
\n if(WIFEXITED(status))
\n {
\n lastcode = WEXITSTATUS(status);
\n }
\n else
\n {
\n lastcode = 100;
\n }
\n return true;
\n }
\n return false;
\n}<\/p>\n
\n{
\n int index = 0;
\n while(genv[index])
\n {
\n index++;
\n }<\/p>\n
\n strncpy(genv[index], item, strlen(item)+1);
\n genv[++index] = nullptr;
\n}
\n\/\/ shell\u81ea\u5df1\u6267\u884c\u547d\u4ee4，\u672c\u8d28\u662fshell\u8c03\u7528\u81ea\u5df1\u7684\u51fd\u6570
\nbool CheckAndExecBuiltCommand()
\n{
\n if(strcmp(gargv[0], "cd") == 0)
\n {
\n \/\/ \u5185\u5efa\u547d\u4ee4
\n if(gargc == 2)
\n {
\n chdir(gargv[1]);
\n lastcode = 0;
\n }
\n else
\n {
\n lastcode = 1;
\n }
\n return true;
\n }
\n else if(strcmp(gargv[0], "export") == 0)
\n {
\n \/\/ export\u4e5f\u662f\u5185\u5efa\u547d\u4ee4
\n if(gargc == 2)
\n {
\n AddEnv(gargv[1]);
\n lastcode = 0;
\n }
\n else
\n {
\n lastcode = 2;
\n }
\n return true;
\n }
\n else if(strcmp(gargv[0], "env") == 0)
\n {
\n for(int i = 0; genv[i]; i++)
\n {
\n printf("%s\\\\n", genv[i]);
\n }
\n lastcode = 0;
\n return true;
\n }
\n else if(strcmp(gargv[0], "echo") == 0)
\n {
\n if(gargc == 2)
\n {
\n \/\/ echo $?
\n \/\/ echo $PATH
\n \/\/ echo hello
\n if(gargv[1][0] == '$')
\n {
\n if(gargv[1][1] == '?')
\n {
\n printf("%d\\\\n", lastcode);
\n lastcode = 0;
\n }
\n }
\n else
\n {
\n printf("%s\\\\n", gargv[1]);
\n lastcode = 0;
\n }
\n }
\n else
\n {
\n lastcode = 3;
\n }
\n return true;
\n }
\n return false;
\n}<\/p>\n
\n\/\/ \u6211\u4eec\u4eca\u5929\u5c31\u76f4\u63a5\u4ece\u7236shell\u4e2d\u83b7\u53d6\u73af\u5883\u53d8\u91cf
\nvoid InitEnv()
\n{
\n extern char **environ;
\n int index = 0;
\n while(environ[index])
\n {
\n genv[index] = (char*)malloc(strlen(environ[index])+1);
\n strncpy(genv[index], environ[index], strlen(environ[index])+1);
\n index++;
\n }
\n genv[index] = nullptr;
\n}<\/p>\n
\n{
\n InitEnv();
\n char command_buffer[basesize];
\n while(true)
\n {
\n PrintCommandLine(); \/\/ 1. \u547d\u4ee4\u884c\u63d0\u793a\u7b26
\n \/\/ command_buffer -> output
\n if( !GetCommandLine(command_buffer, basesize) ) \/\/ 2. \u83b7\u53d6\u7528\u6237\u547d\u4ee4
\n {
\n continue;
\n }
\n \/\/printf("%s\\\\n", command_buffer);
\n \/\/ls
\n \/\/"ls -a -b -c -d"->"ls" "-a" "-b" "-c" "-d"
\n ParseCommandLine(command_buffer, strlen(command_buffer)); \/\/ 3. \u5206\u6790\u547d\u4ee4<\/p>\n
\n {
\n continue;
\n }<\/p>\n
\n }
\n return 0;
\n} <\/p>\n5.4\u3001\u603b\u7ed3<\/h3>\n
![\"\"](\"2025-05-17jy1lc5kw4pi.png\")
<\/p>\n