#! perl -slw
use strict;
use threads;
use threads::shared;
use Net::Telnet;

my %data :shared;

sub thread {
    my( $machine, $user, $pass, $cmd ) = @_;
	$t = new Net::Telnet (
        Timeout => 10,
        Prompt => '>'
    );
	$t->open( $machine );
	$t->login( $user, $pass );
	my @lines :shared = $t->cmd( $cmd );
    $t->close;
    lock %data;
    $data{ $machine } = \@lines;
    return;
}

# AoA each sub array containing machineId, username, password and command to run
my @credentials = ...;

my @threads = map threads->create( \&thread, @$_ ), @credentials;

$_->join for @threads;

## Do something useful with the data gathered in %data.