#! /usr/bin/perl

use strict;
use warnings;
use Benchmark;

timethese (1000000, {
    'substr' => sub { my $string = '123456789B31S';
                      $string = substr($string,4,(length($string)-6)); },
    'tauli'  => sub { my $string = '123456789B31S';
                      $string = substr($string,4,-2); },
    'regexp' => sub { my $string = '123456789B31S';
                      $string =~ s/^.{4}(.+).{2}$/$1/; }});

peters@ronin:~/test> perl perl.pl
Benchmark: timing 1000000 iterations of regexp, substr, tauli...
    regexp: 40 wallclock secs (40.02 usr +  0.00 sys = 40.02 CPU) @ 24987.51/s (n=1000000)
    substr:  7 wallclock secs ( 7.46 usr +  0.00 sys =  7.46 CPU) @ 134048.26/s (n=1000000)
     tauli:  6 wallclock secs ( 5.19 usr +  0.00 sys =  5.19 CPU) @ 192678.23/s (n=1000000)