#!/usr/bin/perl -w
use strict;
use Net::Ping;
use Getopt::Std;

my $protocal 	= "icmp";
my $network 	= "user must enter";
my $start	= 0;
my $end		= 255;
my $timeOut 	= 1;

use vars qw/ $opt_p $opt_N $opt_S $opt_E $opt_T $opt_h/;
getopt( "p:N:S:E:T:h" );
if( $opt_p ) {$protocal = $opt_p;}
if( $opt_N ) {$network	= $opt_N} else { &usage(); exit(); }
if( $opt_S ) {$start	= $opt_S}
if( $opt_E ) {$end	= $opt_E}
if( $opt_T ) {$timeOut	= $opt_T}
if( $opt_h ) {&useage(); exit();}

my $p = Net::Ping->new($protocal,$timeOut);

for(my $node=$start; $node<$end; $node++){
	my $address = "$network.$node";
	print $address,($p->ping($address) ? ' is alive' : ' is not alive'),"\n";
}

$p->close();

sub usage {
print<<DOIT;
	$0 -N<network> [-p<protocal>][-S<start>][-E<end>][-T<timeout>][-h]
	network actually first 3 octects of an IP address
	protocal can be icmp, tcp or udp default is icmp
	start	default 0 
	end	default 255 
	timeout	default 1 
DOIT
}

##</code><code>##

$ ./ping.pl -N 123.321.12 -ptcp
123.321.12.0 is not alive
123.321.12.1 is not alive
^C
// script seemed to hang 

$ ./ping.pl -N 123.321.12 -pudp
123.321.12.0 is not alive
123.321.12.1 is not alive
123.321.12.2 is not alive
123.321.12.3 is not alive
123.321.12.4 is not alive
123.321.12.5 is not alive
123.321.12.6 is not alive
123.321.12.7 is not alive
... 
123.321.12.254 is not alive

$ ./ping.pl -N 123.321.12   
icmp ping requires root privilege at ./ping.pl line 21