Convert hostname to decimal form

Abolish domain-names! Forget ip-addresses! Use easy-to-remember decimal numbers!

It's not exactly complicated code, but a lot of people don't know you can also use decimals instead of ip-addresses: for 206.170.14.75, convert each element into its binary equivalent, join the four strings and convert the resulting string into decimal (which will be a number less than 2^32).

#!/usr/bin/perl -w

use strict;
use Socket;

for my $host (@ARGV) {
        my $addr = inet_ntoa( scalar gethostbyname($host) );
        my $bin;

        $bin .= dec2bin($_) for (split /[.]/, $addr);
        print bin2dec($bin), "\n";
}

sub bin2dec {
        unpack("N", pack("B32", substr("0" x 32 . shift, -32)));
}

sub dec2bin {
        my $str = unpack("B32", pack("N", shift));

        # we only need the lowest 8 bits (ipv4 range 0-255)
        return substr $str, length($str) - 8;
}
[download]

Example:

[ar0n@zendo perl]% perl ip2dec.pl perlmonks.org
3467251275
[download]

Now load up your browser and be amazed! (your perlmonks cookie will, of course, not work)

Comment on Convert hostname to decimal form Select or Download Code

Replies are listed 'Best First'.
RE: Convert hostname to decimal form by japhy (Canon) on Oct 22, 2000 at 05:01 UTC
You can do away with `Socket` and that binary conversion by just using the 4-byte raw data: `#!/usr/bin/perl use strict; for my $host (@ARGV) { my $addr = gethostbyname($host); my $sum = 0; $sum = $sum * 256 + ord for split //, $addr; print "$host: $sum\n"; }` [download] `$_="goto+F.print+chop;\n=yhpaj";F1:eval`	[reply] [d/l]
Re: Convert hostname to decimal form by Anonymous Monk on Nov 24, 2000 at 18:36 UTC
`print unpack('N', scalar gethostbyname($host)), "\n";`	[reply] [d/l]
Re: Convert hostname to decimal form by bittondb (Novice) on Oct 08, 2001 at 06:57 UTC
Decimal representations of IP addresses also lends for fast DB sorts, since the field datatype is UNSIGNED INT, instead of VARCHAR(15).	[reply]