use strict;
use warnings;
use IPC::Run qw( start );

# Initiate the child process
my $data;
my $s = start [ 'ls' ], '>', \$data;

# Show its PID
for my $kid ( @{$s->{KIDS}} ) {
	print $kid->{PID};
}

# pump data in and out, then clean up
$s->pump;
$s->finish;