#!/usr/local/bin/perl
use strict;
use warnings;
use IO::Socket::INET;

my %config = (
              'mail.test.com' => [ 'smtp','pop3' ],
              'localhost'      => [ 'http','dns' ]
              );

my %check;


foreach my $host (keys %config) {
    foreach my $port (@{$config{$host}}) {
        my $host_port = "$host".'_'."_$port";
        $check{$host_port} = IO::Socket::INET->new(
                                                   Timeout  => 1,
                                                   PeerAddr => $host,
                                                   PeerPort => $port,
                                                   Proto    => 'tcp');
    }
}

foreach my $check_it (keys %check) {
    if ($check{$check_it}) {
        print "$check_it is ok\n";
    }
}
[download]

use IO::Socket::Inet;
for (
  ['Mail Servers', 'mail.test.com:110', 'mail.test.com:25'],
  ['Web Servers', 'test.com:80'],
  ['DNS Servers', 'test.com:53'],
) {
  my ($message, @ports) = @$_;
  my $good = 1;
  for (@ports) {
    $good = 0, last unless IO::Socket::INET->new($port);
  }
  print "$message: ", $good ? "Up" : "Down";
  print "\n";
}
[download]

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

Here's how I would do it. YMMV.

#!/usr/bin/perl -w
use strict;
use IO::Socket::INET;

my %services = ( pop => [ 'mail.test.com', 110 ],
         smtp => [ 'mail.test.com', 25 ],
         web => [ 'test.com', 80 ],
         dns => [ 'test.com', 53 ],
         );
my %status;
$status{$_} = 'Up' for keys %services;

while (my ($name,$svc) = each %services) {
    my $sock = IO::Socket::INET->new(Timeout=>1,
                     PeerAddr => $svc->[0],
                     PeerPort => $svc->[1],
                     Proto => 'tcp' )
    or $status{$name} = 'Down';
}

while (my ($name,$sts) = each %status) {
    print "$name server is $sts\n";
}
[download]

# Above all others, add:
use strict;

# Some stuff here

my %connection = (
    pop3 => {
        PeerAddr => 'mail.test.com',
        PeerPort => 110,
    },
# Add the others here, like above
);

my %socket;
while (my ($name, $values) = each %connections)
{
    $socket{$name} = IO::Socket::INET->new(
        Timeout  => 1,
        Proto    => 'tcp',
        ( map { $_ => $values->{$_} } keys %$values ),
    );
}

my $UP   = 'Up';
my $DOWN = 'Down';

my $mail = ($socket{pop3} && $socket{smtp}
    ? $UP
    : $DOWN);

# Do other checks here
[download]

------
We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.

Personally I wouldn't sweat it unless you were planning on vastly expanding this program, or were trying to make it into a more generalized solution, and if that's the case you're definitely in wheel-reinvention territory. :-)

Gary Blackburn
Trained Killer

#!/usr/bin/perl

use IO::Socket::INET;
use Config::IniFiles;

my $cfg = Config::IniFiles->new(-file => *DATA);

my %socket = ();
for my $monitor ( $cfg->GroupMembers('Monitor') ) {
    my ($name) = $monitor =~ /Monitor (.+)/;
    $socket{$name} = IO::Socket::INET->new(
      Timeout  => $cfg->val( $monitor, 'Timeout' ),
      PeerAddr => $cfg->val( $monitor, 'PeerAddr' ),
      PeerPort => $cfg->val( $monitor, 'PeerPort' ),
      Proto    => $cfg->val( $monitor, 'Proto' ),
    );
}

# ...

__DATA__
[Monitor Pop3]
  Timeout  = 1
  PeerAddr = 'mail.test.com'
  PeerPort = 110
  Proto    = 'tcp'

[Monitor SMTP]
  Timeout  = 1
  PeerAddr = 'mail.test.com'
  PeerPort = 25
  Proto    = 'tcp'

[Monitor Web]
  Timeout  = 1
  PeerAddr = 'test.com'
  PeerPort = 80
  Proto    = 'tcp'

[Monitor DNS]
  Timeout  = 1
  PeerAddr = 'test.com'
  PeerPort = 53
  Proto    = 'tcp'
[download]

Naturally, the DATA filehandle could (should) be replaced with a real file--and you magically gain the benefit of multiple configurations. Not to mention all the bells & whistles of IniFiles, like defaults and updates.

Update: fixed small typo

--Solo

--
You said you wanted to be around when I made a mistake; well, this could be it, sweetheart.

See http://www.nagios.org/

Isn't that what IO::Socket::Inet::new is already doing? I don't see how your factory method would be doing anything different. And for what it's worth, the original poster's code is some of the cleanest Perl I've ever seen.

Well, if you integrate configuration files into the factory, your code becomes cleaner. Now lets say you stop using IO::Socket::Inet but switch to something else, you don't have to change from using IO::Socket everywhere, just change how the factory works.

It is clean, yes. But, it's not very extensible, configurable, or customizable. It doesn't take advantage of shared snippets to make maintenance easier. That's what most of the responses have been about. Taking it to the next level, if that's what's desirable and desired.

------
We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.