Commit | Line | Data |
---|---|---|
460b9539 | 1 | /* |
2 | * This file is part of DisOrder. | |
5aff007d | 3 | * Copyright (C) 2004, 2005, 2007, 2008 Richard Kettlewell |
460b9539 | 4 | * |
e7eb3a27 | 5 | * This program is free software: you can redistribute it and/or modify |
460b9539 | 6 | * it under the terms of the GNU General Public License as published by |
e7eb3a27 | 7 | * the Free Software Foundation, either version 3 of the License, or |
460b9539 | 8 | * (at your option) any later version. |
9 | * | |
e7eb3a27 RK |
10 | * This program is distributed in the hope that it will be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
460b9539 | 15 | * You should have received a copy of the GNU General Public License |
e7eb3a27 | 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
460b9539 | 17 | */ |
0590cedc RK |
18 | /** @file server/daemonize.c |
19 | * @brief Go into background | |
20 | */ | |
460b9539 | 21 | |
05b75f8d | 22 | #include "disorder-server.h" |
460b9539 | 23 | |
0590cedc RK |
24 | /** @brief Go into background |
25 | * @param tag Message tag, or NULL | |
26 | * @param fac Logging facility | |
27 | * @param pidfile Where to store PID, or NULL | |
28 | * | |
29 | * Become a daemon. stdout/stderr are lost and DisOrder's logging is | |
30 | * redirected to syslog. It is assumed that there are no FDs beyond 2 | |
31 | * that need closing. | |
32 | */ | |
460b9539 | 33 | void daemonize(const char *tag, int fac, const char *pidfile) { |
34 | pid_t pid, r; | |
35 | int w, dn; | |
36 | FILE *fp; | |
37 | ||
38 | D(("daemonize tag=%s fac=%d pidfile=%s", | |
39 | tag ? tag : "NULL", fac, pidfile ? pidfile : "NULL")); | |
40 | /* make sure that FDs 0, 1, 2 all at least exist (and get a | |
41 | * /dev/null) */ | |
42 | do { | |
43 | if((dn = open("/dev/null", O_RDWR, 0)) < 0) | |
44 | fatal(errno, "error opening /dev/null"); | |
45 | } while(dn < 3); | |
46 | pid = xfork(); | |
47 | if(pid) { | |
48 | /* Parent process. Wait for the first child to finish, then | |
49 | * return to the caller. */ | |
50 | exitfn = _exit; | |
51 | while((r = waitpid(pid, &w, 0)) == -1 && errno == EINTR) | |
52 | ; | |
53 | if(r < 0) fatal(errno, "error calling waitpid"); | |
54 | if(w) error(0, "subprocess exited with wait status %#x", (unsigned)w); | |
55 | _exit(0); | |
56 | } | |
57 | /* First child process. This will be the session leader, and will | |
58 | * be transient. */ | |
59 | D(("first child pid=%lu", (unsigned long)getpid())); | |
60 | if(setsid() < 0) fatal(errno, "error calling setsid"); | |
61 | /* we'll log to syslog */ | |
62 | openlog(tag, LOG_PID, fac); | |
63 | log_default = &log_syslog; | |
64 | /* stdin/out/err we lose */ | |
65 | xdup2(dn, 0); | |
66 | xdup2(dn, 1); | |
67 | xdup2(dn, 2); | |
68 | xclose(dn); | |
69 | pid = xfork(); | |
70 | if(pid) | |
71 | _exit(0); | |
72 | /* second child. Write a pidfile if someone wanted it. */ | |
73 | D(("second child pid=%lu", (unsigned long)getpid())); | |
74 | if(pidfile) { | |
75 | if(!(fp = fopen(pidfile, "w")) | |
76 | || fprintf(fp, "%lu\n", (unsigned long)getpid()) < 0 | |
77 | || fclose(fp) < 0) | |
78 | fatal(errno, "error creating %s", pidfile); | |
79 | } | |
80 | } | |
81 | ||
82 | /* | |
83 | Local Variables: | |
84 | c-basic-offset:2 | |
85 | comment-column:40 | |
86 | End: | |
87 | */ |