1#define _GNU_SOURCE
2#include <fcntl.h>
3#include <unistd.h>
4
5int daemon(int nochdir, int noclose)
6{
7 if (!nochdir && chdir("/"))
8 return -1;
9 if (!noclose) {
10 int fd, failed = 0;
11 if ((fd = open("/dev/null", O_RDWR)) < 0) return -1;
12 if (dup2(fd, 0) < 0 || dup2(fd, 1) < 0 || dup2(fd, 2) < 0)
13 failed++;
14 if (fd > 2) close(fd);
15 if (failed) return -1;
16 }
17
18 switch(fork()) {
19 case 0: break;
20 case -1: return -1;
21 default: _exit(0);
22 }
23
24 if (setsid() < 0) return -1;
25
26 switch(fork()) {
27 case 0: break;
28 case -1: return -1;
29 default: _exit(0);
30 }
31
32 return 0;
33}