Disclaimer: I find the design questionable... you should consider not using constant (in fact Conway's Perl Best Practices recommends against it, e.g. Perl::Critic::Policy::ValuesAndExpressions::ProhibitConstantPragma) and look at alternatives such as using a locked hash (or even a function) to return your "constant" values.

As is said, Perl gives you just enough rope to hang yourself with, so here you go:

package ConstExporter;
use warnings;
use strict;

my %CONSTANTS = (
    foo => "abc",
    bar => "xyz",
    quz => "123",
);

sub import {
    my ($class, @export) = @_;
    my ($callpack) = caller;
    for my $exp (@export) {
        die "bad constant name '$exp'"
            unless exists $CONSTANTS{$exp};
        no strict 'refs';
        *{"${callpack}::$exp"} = sub () { $CONSTANTS{$exp} };
    }
}

1;

[download]

Use it in the usual way: use ConstExporter qw/foo bar/;

In reply to Re^3: Reading the script code from itself by Anonymous Monk
in thread Reading the script code from itself by v_melnik

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.