--- a/check_ajp/check_ajp
+++ b/check_ajp/check_ajp
@@ -7,6 +7,7 @@
 #
 # check_ajp - nagios plugin for jboss monitoring
 # Copyright (C) 2010  Michel Rode <rmichel@devnu11.net>
+# Copyright (C) 2013  Bernd Zeimetz <b.zeimetz@conova.com>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -30,6 +31,8 @@ use strict;
 use Getopt::Long;
 use Socket;
 use Time::HiRes 'time';
+use IO::Socket;
+
 
 my $app = '';
 my $port = '8009';
@@ -37,9 +40,14 @@ my $warntime = '1.5';
 my $crittime = '3';
 my $timeout = '10';
 
-my ($iaddr, $paddr, $proto, $sock, $time1, $time2);
+my ($sock, $time1, $time2);
 my $pong = 'null';
 
+sub conndie{
+	my $msg = shift;
+	print "CRITICAL : $msg\n";
+	exit 2;
+}
 sub xdie{
 	my $msg = shift;
 	printf STDERR "Usage: check_ajp --app ip.of.the.app [--port 8009 --warn 1 --crit 2 --timeout 5]\n\n";
@@ -49,6 +57,10 @@ sub xdie{
 
 GetOptions("app=s" => \$app, "port=s" => \$port, "warn=f" => \$warntime, "crit=f" => \$crittime, "timeout=f" => \$timeout);
 
+if ($app eq '') {
+    xdie('--app not given')
+}
+
 my $ping = pack 'C5'    # Format template.
     , 0x12, 0x34        # Magic number for server->container packets.
     , 0x00, 0x01        # 2 byte int length of payload.
@@ -61,24 +73,23 @@ my $expected = pack 'C5'    # Format tem
     , 0x09                  # Type of packet. 9 = CPong reply.
 ;
 
-$iaddr = inet_aton($app) || xdie("No host given !");
-$paddr = sockaddr_in($port, $iaddr) || xdie("Wrong port !");
-$proto = getprotobyname 'tcp';
-
 $time1 = time();
 
 eval {
 	local $SIG{ALRM} = sub { die "alarm\n" };
 	alarm($timeout);
-	socket $sock, PF_INET, SOCK_STREAM, $proto || xdie("socket !");
-	connect $sock, $paddr  || xdie("connect !");
-	syswrite $sock, $ping || xdie("syswrite !");
-	sysread $sock, $pong, 5 || xdie("sysread !");
+	$sock = IO::Socket::INET->new(Proto => "tcp",
+					PeerAddr  => $app,
+					PeerPort  => $port) || conndie($@);
+	$sock->autoflush(1);
+	print $sock $ping;
+	$sock->recv($pong,5);
+        close $sock;
 	alarm(0);
 }; 
 
 if ($@) {
-	die unless $@ eq "alarm\n";
+	conndie($@) unless $@ eq "alarm\n";
 	$time2 = (time() - $time1);
 	printf "CRITICAL - AJP - Timeout after %1.0fs\n",$time2;
 	exit 2;