{"id":381,"date":"2025-10-13T10:37:30","date_gmt":"2025-10-13T02:37:30","guid":{"rendered":"http:\/\/www.tgwttt.xyz\/?p=381"},"modified":"2025-11-24T16:36:12","modified_gmt":"2025-11-24T08:36:12","slug":"%e5%ae%88%e6%8a%a4%e8%bf%9b%e7%a8%8b","status":"publish","type":"post","link":"https:\/\/www.tgwttt.xyz\/?p=381","title":{"rendered":"\u5b88\u62a4\u8fdb\u7a0b"},"content":{"rendered":"\n

\u5b8c\u6574\u4ee3\u7801\uff1ahttps:\/\/gitee.com\/tgwTTT\/linux-learning-dai\/blob\/master\/netCal<\/a><\/p>\n\n\n\n

\u524d\u8a00<\/strong>\uff1a\u5728\u4e0a\u7bc7\u6587\u7ae0\u4f5c\u8005\u901a\u8fc7\u7f51\u7edc\u8ba1\u7b97\u5668\uff08http:\/\/www.tgwttt.xyz\/?p=368<\/a>\uff09\u8bb2\u89e3\u4e86\u81ea\u5b9a\u4e49\u534f\u8bae\uff0c\u4f46\u662f\u6211\u4eec\u8fd8\u7f3a\u5c11\u4e00\u4e2a\u4e1c\u897f\uff0c\u8bd5\u60f3\u5f53\u6211\u4eec\u767b\u5f55\u4e00\u4e2alinux\u7528\u6237\u65f6\uff0c\u5f53\u5c06\u7a0b\u5e8f\u8dd1\u8d77\u6765\uff0c\u4f46\u662f\u5f53\u6211\u4eec\u5173\u95ed\u7528\u6237\u65f6\uff0c\u6211\u4eec\u6302\u5728\u540e\u53f0\u8fd0\u884c\u7684\u670d\u52a1\u5668\u4f1a\u4e0d\u4f1a\u53d7\u5230\u5f71\u54cd\u5462\uff1f\u7b54\u6848\u662f\u5fc5\u7136\u7684\uff0c\u6240\u4ee5\u6211\u4eec\u5e94\u8be5\u91c7\u53d6\u4ec0\u4e48\u529e\u6cd5\u53bb\u9632\u8303\u5462\uff1f<\/p>\n\n\n\n

\u8fdb\u7a0b\u7ec4<\/strong>\uff1a<\/p>\n\n\n\n

\u2f00\u4e2a\u8fdb\u7a0b\u9664\u4e86\u6709\u2f00\u4e2a\u8fdb\u7a0bID(PID)\u4e4b\u5916 \u8fd8\u5c5e\u4e8e\u2f00\u4e2a\u8fdb\u7a0b\u7ec4\u3002\u8fdb\u7a0b\u7ec4\u662f\u2f00\u4e2a\u6216\u8005\u591a\u4e2a\u8fdb\u7a0b\u7684\u96c6\u5408\uff0c \u2f00\u4e2a\u8fdb\u7a0b\u7ec4\u53ef\u4ee5\u5305\u542b\u591a\u4e2a\u8fdb\u7a0b\u3002 \u6bcf\u2f00\u4e2a\u8fdb\u7a0b\u7ec4\u4e5f\u6709\u2f00\u4e2a\u552f\u2f00\u7684\u8fdb\u7a0b\u7ec4ID(PGID)\uff0c \u5e76\u4e14\u8fd9\u4e2aPGID\u7c7b\u4f3c\u4e8e\u8fdb\u7a0bID\uff0c \u540c\u6837\u662f\u2f00\u4e2a\u6b63\u6574\u6570\uff0c \u53ef\u4ee5\u5b58\u653e\u5728pid_t\u6570\u636e\u7c7b\u578b\u4e2d\u3002<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u5982\u4e0a\u9762\u7684pgid\u5c31\u662f\u8fdb\u7a0b\u7ec4id<\/p>\n\n\n\n

\n

\u7ec4\u2ed3\u8fdb\u7a0b<\/strong><\/em>
\u201c\u7ec4\u957f\u8fdb\u7a0b\u201d \u6307\u7684\u662f \u8fdb\u7a0b\u7ec4\u7684\u7ec4\u957f\uff0c\u4e5f\u5c31\u662f PGID\uff08\u8fdb\u7a0b\u7ec4 ID\uff09\u7b49\u4e8e\u8be5\u8fdb\u7a0b PID \u7684\u90a3\u4e2a\u8fdb\u7a0b\u3002<\/p>\n\n\n\n

\n

\u8fdb\u7a0b\u7ec4\u7ec4\u2ed3\u7684\u4f5c\u2f64\uff1a \u8fdb\u7a0b\u7ec4\u7ec4\u2ed3\u53ef\u4ee5\u521b\u5efa\u2f00\u4e2a\u8fdb\u7a0b\u7ec4\u6216\u8005\u521b\u5efa\u8be5\u7ec4\u4e2d\u7684\u8fdb\u7a0b <\/p>\n\n\n\n

\u8fdb\u7a0b\u7ec4\u7684\u2f63\u547d\u5468\u671f\uff1a \u4ece\u8fdb\u7a0b\u7ec4\u521b\u5efa\u5f00\u59cb\u5230\u5176\u4e2d\u6700\u540e\u2f00\u4e2a\u8fdb\u7a0b\u79bb\u5f00\u4e3a\u2f4c\u3002\u6ce8\u610f\uff1a \u4e3b\u8981\u67d0\u4e2a\u8fdb\u7a0b\u7ec4\u4e2d\u6709\u2f00\u4e2a\u8fdb\u7a0b\u5b58\u5728\uff0c \u5219\u8be5\u8fdb\u7a0b\u7ec4\u5c31\u5b58\u5728\uff0c \u8fd9\u4e0e\u5176\u7ec4\u2ed3\u8fdb\u7a0b\u662f\u5426\u5df2\u7ecf\u7ec8\u2f4c\u2f46\u5173<\/p>\n\n\n\n

<\/p>\n<\/div>\n<\/div>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u4f1a\u8bdd\uff1a<\/strong>\u5728 Linux \u4e2d\uff0c\u201c\u4f1a\u8bdd\uff08Session\uff09\u201d \u662f\u6bd4\u8fdb\u7a0b\u7ec4\uff08Process Group\uff09\u66f4\u9ad8\u4e00\u7ea7\u7684\u8fdb\u7a0b\u7ec4\u7ec7\u5355\u4f4d\uff0c\u6bcf\u4e2a\u4f1a\u8bdd\u53ef\u4ee5\u5305\u542b\u591a\u4e2a\u8fdb\u7a0b\u7ec4\uff0c\u4f46\u53ea\u80fd\u6709\u4e00\u4e2a\u524d\u53f0\u8fdb\u7a0b\u7ec4\u3002<\/p>\n\n\n\n

\u5982\u4f55\u521b\u5efa\u4f1a\u8bdd\u5462\uff1f<\/strong><\/p>\n\n\n\n

\n

include \/<\/p>\n\n\n\n

\u529f\u80fd\uff1a\u521b\u5efa\u4f1a\u8bdd*\u8fd4\u56de\u503c\uff1a\u521b\u5efa\u6210\u529f\u8fd4\u56deSID, \u5931\u8d25\u8fd4\u56de-1<\/p>\n\n\n\n

pid_t setsid(void);<\/p>\n<\/div>\n\n\n\n

\u63a5\u4e0b\u6765\u6211\u4eec\u5c31\u81ea\u5df1\u5b9e\u73b0\u4e00\u4e2a\u5b88\u62a4\u8fdb\u7a0b<\/strong><\/p>\n\n\n\n

#pragma once\n#include\n#include\n#include\n#include\n#include\n#include\n#include\n#include\"Log.hpp\"\nusing namespace LogMoudle;\n\/\/\u5c06\u670d\u52a1\u8fdb\u884c\u5b88\u62a4\u8fdb\u7a0b\u5316\u7684\u670d\u52a1\nconst std::string dev=\"\/dev\/null\";\nvoid Daemon(){\n    \/\/\u5ffd\u7565\u4fe1\u53f7\n    signal(SIGPIPE,SIG_IGN);\n    signal(SIGCHLD,SIG_IGN);\n    if(fork()>0)\n        \/\/\u7236\u8fdb\u7a0b\u9000\u51fa\n        exit(0);\n    \/\/\u5b50\u8fdb\u7a0b\u7ee7\u7eed\uff0c\u5b64\u513f\u8fdb\u7a0b\uff0c\u7236\u8fdb\u7a0b\u5c31\u662f1\n    setsid();\n    \/\/\u5b88\u62a4\u8fdb\u7a0b\u4e0d\u8981\u91cd\u952e\u76d8\u8f93\u5165\u4e5f\u4e0d\u9700\u8981\u5411\u663e\u793a\u5668\u6253\u5370\n    \/\/\u65b9\u6cd5\u4e00\uff1a\u5173\u95ed0,1,2\uff08\u4e0d\u63a8\u8350\uff09\n    \/\/\u65b9\u6cd5\u4e8c\uff1a\u6253\u5f00\/dev\/null\u5c06\u6807\u51c60,1,2\u91cd\u5b9a\u5411\u5230\/dev\/null\n    int fd=open(dev.c_str(),O_RDWR);\n    if(fd<0){\n        LOG(LogLevel::FATAL)<<\"\u6253\u5f00\"<<\/pre>\n\n\n\n
linux\u4e2d\u4e5f\u6709\u81ea\u5df1\u7684\u7cfb\u7edf\u8c03\u7528\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
daemon\uff1a<\/strong><\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u53c2\u6570<\/th>\u542b\u4e49<\/th><\/tr><\/thead>
nochdir<\/code><\/td>\u4f20 0 \u2192 \u5c06\u5de5\u4f5c\u76ee\u5f55\u5207\u5230 \/<\/code>\uff1b\u975e 0 \u2192 \u4fdd\u6301\u539f\u76ee\u5f55<\/td><\/tr>
noclose<\/code><\/td>\u4f20 0 \u2192 \u628a stdin\/stdout\/stderr<\/code> \u91cd\u5b9a\u5411\u5230 \/dev\/null<\/code>\uff1b\u975e 0 \u2192 \u4fdd\u6301\u539f\u6253\u5f00\u6587\u4ef6<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u8fd9\u5c31\u662f\u5b88\u62a4\u8fdb\u7a0b\uff0c\u5b83\u672c\u8d28\u662f\u4e00\u4e2a\u5b50\u8fdb\u7a0b\u3002<\/p>\n\n\n\n
\u4e0e\u5b64\u513f\u8fdb\u7a0b\u5bf9\u6bd4<\/strong><\/p>\n\n\n\n
\u7ef4\u5ea6<\/th>\u5b88\u62a4\u8fdb\u7a0b\uff08daemon\uff09<\/th>\u5b64\u513f\u8fdb\u7a0b\uff08orphan process\uff09<\/th><\/tr><\/thead>
\u4ea7\u751f\u65b9\u5f0f<\/td>\u6709\u610f\u8bbe\u8ba1\uff1a\u8fdb\u7a0b\u4e3b\u52a8\u8c03\u7528 daemon()<\/code> \u6216\u624b\u52a8 fork+setsid+\u53ccfork<\/code> \u7b49\u6b65\u9aa4\uff0c\u4f7f\u81ea\u5df1\u8131\u79bb\u7ec8\u7aef\u3001\u4f1a\u8bdd\u548c\u7236\u8fdb\u7a0b\u3002<\/td>\u65e0\u610f\u4ea7\u751f\uff1a\u7236\u8fdb\u7a0b\u5148 exit<\/code>\uff0c\u5b50\u8fdb\u7a0b\u4ecd\u5728\u8fd0\u884c\uff0c\u4e8e\u662f\u88ab init\uff08\u6216 systemd\uff09\u201c\u6536\u517b\u201d\uff0c\u77ac\u95f4\u53d8\u6210\u5b64\u513f\u3002<\/td><\/tr>
\u662f\u5426\u9884\u671f<\/td>\u5f00\u53d1\u8005 \u4e3b\u52a8\u60f3\u8981 \u7684\u540e\u53f0\u670d\u52a1\u3002<\/td>\u610f\u5916\u4e8b\u4ef6\uff0c\u7a0b\u5e8f\u5458\u901a\u5e38\u4e0d\u5e0c\u671b\u51fa\u73b0\u3002<\/td><\/tr>
\u7236\u8fdb\u7a0b<\/td>\u6700\u7ec8 PPID = 1\uff08\u88ab init \u6536\u517b\uff09\u3002<\/td>\u540c\u6837 PPID = 1\uff08\u88ab init \u6536\u517b\uff09\u3002<\/td><\/tr>
\u63a7\u5236\u7ec8\u7aef<\/td>\u65e0 TTY\uff08\u81ea\u5df1\u8c03\u7528 setsid()<\/code> \u521b\u5efa\u65b0\u4f1a\u8bdd\u5e76\u8131\u79bb\u7ec8\u7aef\uff09\u3002<\/td>\u53ef\u80fd\u4ecd\u6709\u539f TTY\uff0c\u76f4\u5230\u8be5\u7ec8\u7aef\u5173\u95ed\uff1b\u4e0d\u4fdd\u8bc1\u8131\u79bb\u3002<\/td><\/tr>
\u4f1a\u8bdd\/\u8fdb\u7a0b\u7ec4<\/td>\u81ea\u5df1\u65b0\u5efa \u4f1a\u8bdd\uff08SID=PID\uff09 \u548c \u8fdb\u7a0b\u7ec4\uff08PGID=PID\uff09\uff0c\u6210\u4e3a\u4f1a\u8bdd\u9996\u8fdb\u7a0b+\u7ec4\u957f\u3002<\/td>\u6cbf\u7528\u539f\u6765\u7684 \u4f1a\u8bdd\u548c\u8fdb\u7a0b\u7ec4\uff0c\u4e0d\u4f1a\u81ea\u52a8\u8c03\u7528 setsid()<\/code>\uff0c\u56e0\u6b64\u4e0d\u662f\u4f1a\u8bdd\u9996\u8fdb\u7a0b\u3002<\/td><\/tr>
\u751f\u547d\u5468\u671f<\/td>\u7cfb\u7edf\u7ea7\u670d\u52a1\uff0c\u5e38\u9a7b\uff0c\u968f\u7cfb\u7edf\u5173\u95ed\u6216\u624b\u52a8 systemctl stop<\/code> \u7ed3\u675f\u3002<\/td>\u968f\u81ea\u8eab\u903b\u8f91\u7ed3\u675f\uff1b\u751f\u547d\u5468\u671f\u4e0e\u201c\u5b64\u513f\u201d\u72b6\u6001\u65e0\u5173\uff0c\u53ea\u662f\u7236\u8fdb\u7a0b\u6362\u4e86\u3002<\/td><\/tr>
\u8d44\u6e90\u5360\u7528<\/td>\u4e3b\u52a8 chdir(\"\/\")<\/code>\u3001umask(0)<\/code>\u3001\u5173\u95ed\/\u91cd\u5b9a\u5411 0\/1\/2\uff0c\u8d44\u6e90\u5e72\u51c0\u3002<\/td>\u4fdd\u6301\u539f\u5de5\u4f5c\u76ee\u5f55\u3001\u6587\u4ef6\u63cf\u8ff0\u7b26\u3001\u4fe1\u53f7\u5904\u7406\u7b49\uff0c\u53ef\u80fd\u6b8b\u7559\u8d44\u6e90\u3002<\/td><\/tr>
\u65e5\u5fd7\/\u8f93\u51fa<\/td>\u81ea\u5df1\u63a5\u7ba1 syslog \u6216\u6587\u4ef6\uff0c\u4e0d\u5f80\u7ec8\u7aef\u5199\u3002<\/td>\u82e5\u539f\u6765 stdout \u6307\u5411\u7ec8\u7aef\uff0c\u53ef\u80fd\u7ee7\u7eed\u5199\uff0c\u4f46\u7ec8\u7aef\u5df2\u5173\u95ed\u65f6\u4f1a\u6536\u5230 SIGPIPE<\/code> \u6216\u5199\u5931\u8d25\u3002<\/td><\/tr>
\u793a\u4f8b<\/td>httpd<\/code>\u3001sshd<\/code>\u3001crond<\/code>\u3001systemd-logind<\/code> \u7b49\u7cfb\u7edf\u670d\u52a1\u3002<\/td>bash<\/code> \u91cc\u6267\u884c sleep 100 &<\/code> \u540e\u9000\u51fa bash\uff1bsleep<\/code> \u77ac\u95f4\u6210\u4e3a\u5b64\u513f\u8fdb\u7a0b\u3002<\/td><\/tr>
\u4e00\u53e5\u8bdd\u603b\u7ed3<\/td>\u201c\u4e3b\u52a8\u79bb\u5a5a\uff0c\u51c0\u8eab\u51fa\u6237\uff0c\u53e6\u7acb\u95e8\u6237\u201d \u2014\u2014 \u8131\u79bb\u7ec8\u7aef\u3001\u8131\u79bb\u7236\u8fdb\u7a0b\uff0c\u6210\u4e3a\u540e\u53f0\u670d\u52a1\u3002<\/td>\u201c\u7236\u6bcd\u53cc\u4ea1\uff0c\u88ab init \u6536\u517b\u201d \u2014\u2014 \u53ea\u662f\u7236\u8fdb\u7a0b\u5148\u6b7b\uff0c\u5b50\u8fdb\u7a0b\u88ab\u52a8\u53d8\u6210\u5b64\u513f\uff0c\u6ca1\u6709\u505a\u8131\u79bb\u64cd\u4f5c\u3002<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u4eca\u5929\u7684\u66f4\u65b0\u5c31\u5230\u8fd9\u91cc\uff0c\u5982\u6709\u9519\u8bef\u6b22\u8fce\u6307\u51fa\uff01\uff01\uff01<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
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