Perl + forking

I have a perl script that forks a command from the parent process and then kills it a few seconds later. The problem I am running into is that sometimes the process isn't killed(the script tries to kill the wrong pid). For whatever reason I am having to increment the pid of my spawned process by +1 to get the correct number. Please see the code below...


$SIG{CHLD} = 'IGNORE';
my $pid = fork();
if (not defined $pid) {
warn "resources not available.\n";
}
elsif ($pid == 0) {
exec($cmd);
exit(0);
}
else {
sleep(2);
$pid++;
kill 9, $pid;
}


Any help is much appreciated!

if that fork(); is a function can we see it? maybe the value of pid is being created differently from how you think?

bazz