In addition to what the others said, I would also like to pint out that you can build RegExes "on the fly" and get rid of that foreach (keys ... loop in your program. I solved the original problem because it is easier ;-): 
#!perl

use strict;
use warnings;

my %acronyms = (
   'HTML'    => "Hypertext Markup Language",
   'ICBM'    => "Intercontinental Ballistic Missile",
   'EEPROM'  => "Electronically-erasable programmable read only memory
+",
   'SCUBA'   => "Self Contained Underwater Breathing Aparatus",
   'FAQ'     => "Frequently Asked Questions",
   'LCARS'   => "Library Computer And Retrieval System",
   'NASA'    => "National Aeronautical and Space Administration"
);

my $regex;
{
   my $temp = join '|', map quotemeta, keys %acronyms;
   $regex = qr/($temp)/o;
}

while (<>) {
   s/$regex/$1 ($acronyms{$1})/g;
   print;
}

[download]
Anyways, you should always use strict; no matter what; it helps a lot with syntax problems.

Hope this helped.
CombatSquirrel.
Entropy is the tendency of everything going to hell.

In reply to Re: Code Optimization v5.8.1 by CombatSquirrel
in thread Code Optimization v5.8.1 by bluethundr

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.