You say you want to count how many times the variable appears in the file, but your code tries to count the number of lines that contain the variable. If you did intend the former, you can count the number of occurrences in one go:

while (<FILE>) {
    $count += () = /\Q$constant\E/g;
}
print "$constant occurs $count times\n";

[download]

In my experience, small files (anything less than several megabytes) often perform better if you slurp the whole thing in, rather than looping over each line:

use File::Slurp;
my $constant = '$_';
$_ = read_file('filename.pl');
$count = () = /\Q$constant\E/g;
print "$constant occurs $count times\n";

[download]

In reply to Re: Issue with regex matching by wanna_code_perl
in thread Issue with regex matching by sowais

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.