This is actually very cool: 
package Constants;

use base 'Exporter';
our @EXPORT = grep {
    substr( $_, 0, 2 ) eq 'C_'
 && __PACKAGE__->can( $_ );
} keys %Constants::;

[download]
The way I used to do it was to essentially use a source filter: I'd have a BEGIN block inside my Definitions.pm file read the file itself in and look for "use constant" lines:
Constant Amusement (auto export trick)

Anyone doing a lot of work with perl constants might want to skim through those talk notes, by the way. And in general, these days I'd recommend staying away from constants altogether -- their utility rarely makes up for their annoyances (e.g no sigil, so they don't interpolate very smoothly). Also a case can be made for keeping definitions of things in a YAML file instead of using perl code to store configuration (programmatic modification of YAML is a lot easier than parsing perl).

In reply to Re^2: How to include a large number of constants? by doom
in thread How to include a large number of constants? 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! —
  • 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.