#!/usr/bin/perl
use strict;
use warnings;
# use Benchmark qw(:all) ; # WindowsOS
use Benchmark::Forking qw( timethese cmpthese ); # UnixOS

my $str = "       test of white space";

my $results = timethese(100000000,
			{ 'regex'  => sub { $str =~ /^\s/ },
			      'substr' => sub { substr($str, 0, 1) eq ' ' },
			      'ord'    => sub { ord($str) == 32 },
			}, 'none');
cmpthese( $results );

__END__

$ perl test.pl
             Rate  regex substr    ord
regex   9225092/s     --   -44%   -87%
substr 16556291/s    79%     --   -77%
ord    73529412/s   697%   344%     --

##</code><code>##

my @strs = ("1234  pass  25  30 1",
	    "      pass  25  30 2",
	    "1965  pass  35  45 1",
	    "      pass  35  45 2");

foreach my $sample (@strs) {
    if (ord($sample) == 32) {
	say "Matched: " . $sample;
    }
}

__END__

$ perl test.pl
Matched:       pass  25  30 2
Matched:       pass  35  45 2