Ah yes, I see. In that case, you’re going to have to read through the whole file, and I doubt there’s much you can do to speed up the loop.

BTW, when I saw the regex /123456$/, I assumed you wanted to match 123456 at the end of a line — that’s what the $ anchor means in a regex. If you want to match a literal $, you need to escape it: m{123456\$} or:

use strict;
use warnings;
use autodie;

...

my $password = '123456';

open(FH, '<', "../Tests/10-million-combos.txt");
$counter  = 0;
$counter2 = 0;

while (<FH>)
{
    ++$counter;
    ++$counter2 if /^Q$password/;
}

print "Num. Line : $counter - Occ : $counter2\n";
close FH;

[download]

See quotemeta.

Hope that helps,

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

In reply to Re^3: How to optimize a regex on a large file read line by line ? by Athanasius
in thread How to optimize a regex on a large file read line by line ? by John FENDER

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.