'vpps-qua'=>672, 'cimplex'=>673, 'acap'=>674,
 'dctp'=>675, 'vpps-via'=>676, 'vpp'=>677,
 'ggf-ncp'=>678, 'mrm'=>679, 'entrust-aaas'=>680,
 'entrust-aams'=>681, 'xfr'=>682, 'corba-iiop'=>683,
 'corba-iiop-ssl'=>684, 'mdc-portmapper'=>685, 'hcp-wismar'=>686,
 'asipregistry'=>687, 'realm-rusd'=>688, 'elcsd'=>704,
 'agentx'=>705, 'borland-dsj'=>707, 'entrust-kmsh'=>709,
 'entrust-ash'=>710, 'cisco-tdp'=>711, 'netviewdm1'=>729,
 'netviewdm2'=>730, 'netviewdm3'=>731, 'netgw'=>741,
 'netrcs'=>742, 'flexlm'=>744, 'fujitsu-dev'=>747,
 'ris-cm'=>748, 'kerberos-adm'=>749, 'rfile'=>750,
 'pump'=>751, 'qrh'=>752, 'rrh'=>753,
 'tell'=>754, 'nlogin'=>758, 'con'=>759,
 'ns'=>760, 'rxe'=>761, 'quotad'=>762,
 'cycleserv'=>763, 'omserv'=>764, 'webster'=>765,
 'phonebook'=>767, 'vid'=>769, 'cadlock'=>770,
 'rtip'=>771, 'cycleserv2'=>772, 'submit'=>773,
 'rpasswd'=>774, 'entomb'=>775, 'wpages'=>776,
 'multiling-http'=>777, 'wpgs'=>780, 'concert'=>786,
 'qsc'=>787, 'mdbs_daemon'=>800, 'device'=>801,
 'fcp-udp'=>810, 'itm-mcell-s'=>828, 'pkix-3-ca-ra'=>829,
 'rsync'=>873, 'iclcnet-locate'=>886, 'iclcnet_svinfo'=>887,
 'accessbuilder'=>888, 'cddbp'=>888, 'omginitialrefs'=>900,
 'xact-backup'=>911, 'ftps-data'=>989, 'ftps'=>990,
 'nas'=>991, 'telnets'=>992, 'imaps'=>993,
 'ircs'=>994, 'pop3s'=>995, 'vsinet'=>996,
 'maitrd'=>997, 'busboy'=>998, 'garcon'=>999,
 'puprouter'=>999, 'cadlock'=>1000, 'surf'=>1010
);

%connected = reverse %connected;

##sort and assign hash index array
my @ports = sort by_number keys %connected;

##look for list argument
&list if $ARGV[0] eq "list";

##attempt to connect to all ports in hash index, then display open ports
foreach $port (@ports) {
    $sock = IO::Socket::INET->new("$peer:$port");
    print "\nPort $port $connected{$port} open\n" if ($sock);
}
print "Done.\n";
exit;

##usage sub
sub usage {
    print "
  Portscanner 1.0

  Usage: portscan <server>
         portscan list\n\n";
    exit;
}

##list sub
sub list {
    foreach $port (@ports) {
        print "Port $port $connected{$port}\n";
    }
    exit;
}

##hash index sort sub
sub by_number {
    if ( $a < $b ) { -1 }
    elsif ( $a > $b ) { 1 }
    else { 0 }
}

=head1 NAME

Portscanner 1.0 - Reports listening ports and their associated service

=head1 Author

James Loope, cronus@pcis.net

=head1 Copyright

Do with it what you please.

=head1 DESCRIPTION

See README

=head1 README

A portscanner for those of us who haven't memorized the common ports map. It scans all common
ports between 1 and 1023 and reports open ports and their common use.

=head1 PREREQUISITES

This script requires IO::Socket

=pod OSNAMES

Linux