#!/usr/bin/perl
use Benchmark;

$buf = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';

timethese(10000000, {
1 => sub { if($buf =~ /JKL/){} },
2 => sub { if(index($buf, 'JKL')){} },
});

----------------------------------------------------------------------

Benchmark: timing 10000000 iterations of 1, 2...
1: 5 wallclock secs ( 4.53 usr + 0.01 sys = 4.55 CPU) @ 2199736.03/s
(n=10000000)
2: 3 wallclock secs ( 1.97 usr + 0.03 sys = 2.00 CPU) @ 4997501.25/s
(n=10000000)