If I am not mistaken, this can be rewritten as:

#!/usr/bin/perl -w
use strict;
my ($wholefile);
my (@keys, %SUBS);
$SUBS{'b'} = 1;
$SUBS{'c'} = 1;
local $/;
open(H,qq|$ARGV[0]|) or die "USAGE: wierd2.pl <filename>"; #sloppy exa
+mple
$wholefile .= <H>;
close(H);
foreach (keys %SUBS) {
    while($wholefile=~m/\b$_\b/g){
    push @keys, $_;
    }
}
1;
[download]

Of course, I have no idea how:

You are getting the %SUBS hash populated in the first place. I thought that was the purpose of the script?

Why you would want to do this

Celebrate Intellectual Diversity

---

In reply to Re: Slow Regex - How to Optimize by InfiniteSilence
in thread Slow Regex - How to Optimize by noslenj123

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.