#!/usr/bin/perl

use strict;
use warnings;
use Net::OpenSSH;

my @hosts=( 'user@server1.com','user@server2.com','user@server3.com' );
my $cmd='uptime';
my %conn = map { $_ => Net::OpenSSH->new($_) } @hosts;
my @pid;
for my $host (@hosts) {
      open my($fh), '>', "/tmp/out-$host.txt"
        or die "unable to create file: $!";
      push @pid, $conn{$host}->spawn({stdout_fh => $fh}, $cmd);
}
waitpid($_, 0) for @pid;
exit;