regex: 37.940104 seconds
substr: 14.430599 seconds

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;
use Time::HiRes qw/ gettimeofday tv_interval /;

#load up the numbers
open my $fh, "< nums.out" or die;
my @numbers = <$fh>;
my $first_three;
my ($start, $stop, $run_time);

my $count = 100;

$start = [gettimeofday()];
for (0..$count)
{
    foreach my $phone (@numbers) 
    {
        ($first_three) = $phone =~ /(\d{3})/;
    }
}
$stop = [gettimeofday()];
$run_time = tv_interval($start,$stop);
print "regex: $run_time seconds\n";

$start = [gettimeofday()];
for (0..$count)
{
    foreach my $phone (@numbers) 
    {
        $first_three = substr $phone, 0, 3;
    }
}
$stop = [gettimeofday()];
$run_time = tv_interval($start,$stop);
print "substr: $run_time seconds\n";