#!/usr/local/bin/perl -w
use strict;
use Benchmark;

my $testlarge = "a " x 100000;
my $testsmall = "a b c d e f";
timethese(-10,{
      One   => sub { my ($y) = (split(/\s+/,$testlarge))[0]; },
      Two   => sub { my ($y) = (split(/\s+/,$testsmall))[0]; },
      Three => sub { my $y = ( $testsmall =~ (/([^\s]*)\s+/g))[0]; },
      Four  => sub { my $y = ( $testlarge =~ (/([^\s]*)\s+/g))[0]; },
            });
mik@mach5:/home/mik/monk)./benchthis.pl
Benchmark: running Four, One, Three, Two, each for at least 10 CPU seconds...
      Four: 19 wallclock secs (18.38 usr +  0.02 sys = 18.40 CPU) @  1.14/s (n=21)
       One: 13 wallclock secs (12.72 usr +  0.00 sys = 12.72 CPU) @  2.12/s (n=27)
     Three: 12 wallclock secs (10.28 usr +  0.00 sys = 10.28 CPU) @ 12748.55/s (n=131071)
       Two: 11 wallclock secs (10.00 usr +  0.00 sys = 10.00 CPU) @ 18600.60/s (n=186006)