#!/usr/bin/perl

use Net::hostent;
use Socket;
use File::Basename;
$PROGNAME=basename($0);

if ($ARGV[0] eq "" || $ARGV[0] eq "--help" || $ARGV[0] eq "-h") {
system("clear");
print <<END;


   Usage: $PROGNAME <hostname|IP|decimal> 

            ex:  a)  $PROGNAME www.yahoo.com
		 b)  $PROGNAME 204.71.200.74
		 c)  $PROGNAME 3427256394 

This will:
	a) convert a hostname into it's decimal equivalent.
	b) convert a dotted-quad IP into it's decimal equivalent.
	c) convert a decimal string into it's dotted-quad IP equivalent.

END
   exit;
}

sub i2d {
for $host ( @ARGV ) {
        unless ($h = gethost($host)) {
                warn "$0: no such host: $host\n";
         next;
        }

	($oct1, $oct2, $oct3, $oct4) = split(/\./, $host);
	$exp1 = 2 ** 24;
	$exp2 = 2 ** 16;
	$exp3 = 2 ** 8;
	$exp4 = 2 ** 0;
	$num1 = $oct1 * $exp1;
	$num2 = $oct2 * $exp2;
	$num3 = $oct3 * $exp3;
	$num4 = $oct4 * $exp4;
	$newnum = $num1 + $num2 + $num3 + $num4;
	system("clear");
	printf ("\n\n$host [%s] converts to $newnum\n\n", $h->name);
}
}

sub h2d {
for $host ( @ARGV ) {
	unless ($h = gethost($host)) {
        	warn "$0: no such host: $host\n";
       	 next;
    	}
	$s=inet_ntoa($h->addr);
	($oct1, $oct2, $oct3, $oct4) = split(/\./, $s);
        $exp1 = 2 ** 24;
        $exp2 = 2 ** 16;
        $exp3 = 2 ** 8;
        $exp4 = 2 ** 0;
        $num1 = $oct1 * $exp1;
        $num2 = $oct2 * $exp2;
        $num3 = $oct3 * $exp3;
        $num4 = $oct4 * $exp4;
        $newnum = $num1 + $num2 + $num3 + $num4;
        system("clear");
        printf ("\n\n$host [%s] converts to $newnum\n\n", inet_ntoa($h->addr));

}
}

sub d2i {
	$dec=$ARGV[0];
	$ip=`nslookup -sil $dec |grep "Name:"`;
	($trash,$ip)=split(/\s+/,$ip);
	$host=$ip;  
	unless ($h = gethost($host)) {
                warn "$0: no such host: $host\n";
         next;
        }
	$s=inet_ntoa($h->addr);
	system("clear");
	printf ("\n\n$dec converts to $ip [%s]\n\n", inet_ntoa($h->addr));
}

if ($ARGV[0] =~ /^[A-Za-z]/) {
	&h2d;
} elsif ($ARGV[0] =~ m/^([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5])$/) {
	&i2d;
} else {
	&d2i;
}