diplodocus.org Git - nmh/blob - sbr/push.c

   1
   2 /*
   3  * push.c -- push a fork into the background
   4  *
   5  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 #include <h/mh.h>
  11 #include <h/signals.h>
  12 #include <signal.h>
  13
  14
  15 void
  16 push(void)
  17 {
  18     pid_t pid;
  19     int i;
  20
  21     for (i = 0; (pid = fork()) == -1 && i < 5; i++)
  22         sleep (5);
  23
  24     switch (pid) {
  25         case -1:
  26             /* fork error */
  27             advise (NULL, "unable to fork, so can't push...");
  28             break;
  29
  30         case 0:
  31             /* child, block a few signals and continue */
  32             SIGNAL (SIGHUP, SIG_IGN);
  33             SIGNAL (SIGINT, SIG_IGN);
  34             SIGNAL (SIGQUIT, SIG_IGN);
  35             SIGNAL (SIGTERM, SIG_IGN);
  36 #ifdef SIGTSTP
  37             SIGNAL (SIGTSTP, SIG_IGN);
  38             SIGNAL (SIGTTIN, SIG_IGN);
  39             SIGNAL (SIGTTOU, SIG_IGN);
  40 #endif
  41             freopen ("/dev/null", "r", stdin);
  42             freopen ("/dev/null", "w", stdout);
  43             break;
  44
  45         default:
  46             /* parent, just exit */
  47             done (0);
  48     }
  49 }
  50