Write it correctly the first time, unless your being paid by the hour. Comments are for clarity. Code is not meant to be self documenting. 
use strict;
use warnings;
use Benchmark ':hireswallclock', 'cmpthese';


my $str = "FOOFOOFOOFOOFOOFOOFOOFOOFOOFOOFOOFOOFOOFOOZOOCOOFOOFOOFOOFO
+OFOOFOOFOO";
my $pos = 0;
my $res = '';

cmpthese(2000000, {'substrindex' => sub {
    $res = substr($str, index($str, 'ZOO'), 6);
    #print $res."\n";
},
'regexp' => sub{
    $str =~ /(ZOO.{3})/;
    $res = $1;
    #print $res."\n";
}
}
);

[download]
                 Rate      regexp substrindex
regexp       627353/s          --        -81%
substrindex 3367003/s        437%          --

[download]

In reply to Re^4: how to find this substring? by bulk88
in thread how to find this substring? by Anonymous Monk

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