src/legacy/daemon.c

   1 #define _GNU_SOURCE
   2 #include <fcntl.h>
   3 #include <unistd.h>
   4
   5 int 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 }