I'm not sure what's going on. I tested it and it works for me. I suspect that something changed from when you ran it and when you posted it. Incidentally, here's something a bit closer to how I would write that:

use strict;

my $matchtext = shift || die &usage;

if ( ! is_valid_pattern( $matchtext ) ) {
    die "'$matchtext' is not a valid regular expression.";
}

my $page = "myfilename.html";
open  PAGE,  "< $page" or die "Cannot open $page for reading: $!";

while (<PAGE>) {
    print "There was an instance of $matchtext on line $.:\n\t$_\n" if
+ /$matchtext/;
}

close PAGE;

sub usage {
    print "Usage: filematch.pl text_to_match";
}

sub is_valid_pattern {
    my $pattern = shift;
    return eval { "" =~ /$pattern/; 1 } || 0;
}

[download]

Cheers,
Ovid

Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.

In reply to (Ovid) Re: Simple REG/EX Question by Ovid
in thread Simple REG/EX Question by mr_dont

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.