However it doesn't work. What am I doing wrong?

AnyEvent::DNS::DOMAIN_PORT is a constant function, which means it gets inlined, and within AnyEvent::DNS, the instances of DOMAIN_PORT are replaced by 53 by the compiler by the time the module is loaded and before control returns to your code. (See e.g. perl -MO=Deparse "`perldoc -l AnyEvent::DNS`")

At the moment, I don't see a way to modify the value of DOMAIN_PORT within AnyEvent::DNS itself from the outside, meaning you may have to resort to modifying the module's code. Constant Functions explains several ways to prevent inlining.

(There may be some Devel::* modules or some other trickery that could prevent inlining from the outside, but I'm currently unaware of any such modules, though I would be interested to learn about such things.)

In reply to Re: How to redefine a modules private function? by haukex
in thread How to redefine a modules private function? by sectokia

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.