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

   1
   2 /*
   3  * push.c -- push a fork into the background
   4  *
   5  * $Id$
   6  *
   7  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   8  * COPYRIGHT file in the root directory of the nmh distribution for
   9  * complete copyright information.
  10  */
  11
  12 #include <h/mh.h>
  13 #include <h/signals.h>
  14 #include <signal.h>
  15
  16
  17 void
  18 push(void)
  19 {
  20     pid_t pid;
  21     int i;
  22
  23     for (i = 0; (pid = fork()) == -1 && i < 5; i++)
  24         sleep (5);
  25
  26     switch (pid) {
  27         case -1:
  28             /* fork error */
  29             advise (NULL, "unable to fork, so can't push...");
  30             break;
  31
  32         case 0:
  33             /* child, block a few signals and continue */
  34             SIGNAL (SIGHUP, SIG_IGN);
  35             SIGNAL (SIGINT, SIG_IGN);
  36             SIGNAL (SIGQUIT, SIG_IGN);
  37             SIGNAL (SIGTERM, SIG_IGN);
  38 #ifdef SIGTSTP
  39             SIGNAL (SIGTSTP, SIG_IGN);
  40             SIGNAL (SIGTTIN, SIG_IGN);
  41             SIGNAL (SIGTTOU, SIG_IGN);
  42 #endif
  43             freopen ("/dev/null", "r", stdin);
  44             freopen ("/dev/null", "w", stdout);
  45             break;
  46
  47         default:
  48             /* parent, just exit */
  49             done (0);
  50     }
  51 }
  52