Im trying to get this fork thing down. I created a program that kills a child process after a certain amount of time if it hasn't exited. However I do not know how to get the child's PID, fork return 0 when its a child not its PID. Right now Im using 1 + the programs id but if something gets invoded before my fork I know that that might not be the case. So any idea's on how to get this. Thanks. 
#!/usr/bin/perl -w

use strict;
use POSIX qw(:errno_h);
use POSIX qw(:sys_wait_h);

$SIG{CHLD} =  "IGNORE";

my ($child, $script, $cleanup, $time);

&create_child;
sleep($time);
&reaper;

sub create_child {

  unless($child = fork()) {
    die "Cannot fork: $!" unless defined $child;
    exec($script);
  }

  $child++;

}
# Some values are from get_args sub not shown
sub reaper {

  if(kill 0 => $child) {
    print "Child timed out, sending signal 15\n";
    kill 15, $child;
    exec($cleanup);
  } elsif ($! == EPERM) {
    print "Child has changed its UID\n";
  } elsif ($! == ESRCH) {
    print "Child is already dead\n";
  } else {
    warn "Could not check child's PID: $!\n";
  }

}

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In reply to Child PID? by Anonymous Monk

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