I noticed that you created a copy of the hash, and modified the copy of the hash, not the original hash. If you want to modify the original hash, you need to do something like below...

sub loader{
 # loads values into hash..
 my $tail = shift;
 my $h_ref = shift;
 
 print 'In sub:'.Dumper($h_ref);

 $h_ref->{'one'}='thing_'.$tail;
 $h_ref->{'two'}='thong_'.$tail;

 print 'After add:'.Dumper($h_ref);
}

[download]
Your code my %h_ref = %{+shift}; created a local copy of the hash.

In reply to Re: Passing hashes by reference by Roger
in thread Passing hashes by reference by wolis

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.