The unix documentation I have read says you can call waitpid with a negitive pid to wait on an entire process group. However, the perl docs for the function of the same name don't mention this.

The following program tests this out: 

use strict;

if (my $pid = fork)
{
   # parent
   setpgrp($pid, $pid);

   waitpid($pid, 0);
   while (waitpid(-$pid, 0) != -1) {}
   exit;
}
else
{
   # child
   if (!(my $pid = fork))
   {
      # grandchild
      sleep(1) while 1;
   }
}

[download]
Unfortunately it doesn't seem to work on my system (perl 5.6, Tru64). The parent process exits, without waiting for the grandchild process. Is there another way of waiting on a process group?

In reply to waiting on a process group by Anonymous Monk

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