cutudl:

You've got two good possibilities above, and here's a third: Perhaps you're working with different hashes, something like this:

$ cat floog.pl
#!/usr/bin/perl

package Utils;
sub make_hash_table {
    %hash = qw(a,b,c,d);
}

package main;
use Data::Dumper;

Utils::make_hash_table();
print Dumper(\%hash);
print Dumper(\%Utils::hash);
$ perl floog.pl
$VAR1 = {};
$VAR1 = {
          'a,b,c,d' => undef
        };
[download]

Why do you have so many radically different possibilities? Simple--you didn't show a simple program that illustrates the problem, or otherwise give enough detail to adequately describe the problems you're having. So we get to play guessing games if we feel motivated enough to try to help. If you spend a little more effort asking good questions, you can greatly increase the possibility of getting a your questions solved quickly.

...roboticus

When your only tool is a hammer, all problems look like your thumb.