#!/usr/bin/perl -w

use strict;
use Benchmark;

use vars qw/@ip_strings/;

# these are all made up I hope

@ip_strings = qw(192.168.1.1. 192.168.1.2 152.2.100.2 204.165.43.1 1.2.3.4 152.2.1.23 112.145.165.205 2.2.2.2. 4.5.6.7 8.9.10.12 2.4.6.8 10.12.14.16);

timethese (10000, {
        'split-em',
        q{
                my @packed_ips;
                foreach (@ip_strings) { 
                        push @packed_ips, pack 'C4', split /\./, $_;
                }
        },
        'regex-em',
        q{
                my @packed_ips;
                foreach (@ip_strings) {
                        push @packed_ips, 
                                pack 'C4', /(\d+)\.(\d+)\.(\d+)\.(\d+)/;
                }
        }
        }
);

##</code><code>##

Benchmark: timing 10000 iterations of regex-em, split-em...
  regex-em:  2 wallclock secs ( 3.64 usr +  0.00 sys =  3.64 CPU)
  split-em:  3 wallclock secs ( 3.13 usr +  0.00 sys =  3.13 CPU)
bash-2.04$ perl pack_ip.pl
Benchmark: timing 10000 iterations of regex-em, split-em...
  regex-em:  3 wallclock secs ( 4.03 usr +  0.00 sys =  4.03 CPU)
  split-em:  3 wallclock secs ( 3.76 usr +  0.00 sys =  3.76 CPU)