#!/usr/bin/perl
use warnings;
use strict;
use IPC::Open3;
$|=1;

my $pid=open3(\*IN,\*OUT,0,'ls -la');

#getresult 
while(<OUT>)
{
    print;
    if(eof(OUT))
    {
        goto GOLAST;
    }
}
GOLAST:

close IN;
close OUT;