#!/usr/bin/perl -w

use strict;
use POSIX ":sys_wait_h";

defined (my $pid = fork()) or die "D'oh";

if ( $pid ) {
  print "$$ gonna wait...\n";
  my $kid;
  do {
   $kid = waitpid $pid, WNOHANG;
  } until ( $kid > 0 );
  print "Ok, done waiting\n";
} else {
    exec 'sleep 10; echo "Done sleeping\n"';
}