#!/usr/bin/perl -t

use IO::Socket;
my ($line, $port, $sock, @servers);
my $VERSION='1.0';

($server = $ARGV[0]) || &usage;
$begin = ($ARGV[1] || 0);

for ($port=$begin;$port<=65000;$port++) {
        $sock = IO::Socket::INET->new(PeerAddr => $server,
                                        PeerPort => $port,
                                        Proto => 'tcp');
        if ($sock)      {
                print "Connected on port $port\n";
        } else {
                # print "$port failed\n";
        }
}  #  End for

sub usage       {
        print "Usage: portscan hostname [start at port number]\n";
        exit(0);
}

=head1 NAME

portscan - Scans a host on TCP ports to determine what is listening

=head1 DESCRIPTION

Determines on which TCP ports a host is listening for incoming connect
+ions.
Useful for determining what services are running on a server.

=head1 PREREQUISITE

uses IO::Socket

=head1 COREQUISITE

None

=head1 README

Determines on which TCP ports a host is listening for incoming connect
+ions.
Useful for determining what services are running on a server.

=pod OSNAMES

MSWin32, Unix

=pod SCRIPT CATEGORIES

Networking

=cut

# pretty straighforward very useful though - -