#!/usr/local/bin/perl

use IO::Socket;

## Array of ports that you want to check.
$port = "27015";
$remoteip = "www.your_server.com";

print "\nChecking for service at $remoteip\n";
print "  ";
print "=" x (length($remoteip) + 25);
print "\n\n";

 $connected = 0;
 $checkport = IO::Socket::INET->new(
              PeerAddr => "$remoteip",
              PeerPort => "$port",
              Proto => 'tcp',
              Timeout => '0') or $connected = 1;

 if (!($connected)) {
   print "  Port $port is up.\n";
 } else {
  print "  Port $port is down.\n";
 }
 close $checkport;