#!/usr/bin/perl -wT
use strict;

%ENV = ();           # clean out the %ENV hash to prevent mischief
$ENV{PATH} = '/bin';

my @pids;                                   # array for storing childrens pids
my $cmd = 'sleep 2; echo "I am child $$"';  # command children will execute

for (1..4) {
  my $childpid = fork() or exec($cmd);  # fork off a child
  push(@pids,$childpid);                # store the childs pid in @pids
}

print "My Children: ", join(' ',@pids), "\n";

waitpid($_,0) for @pids;                # wait for children to finish
print "Children are done\n";