Can just use the fully qualified name to overwrite the sub.

Unfortunately not - the change is visible within your script, but not within the module.

Foo.pm

package Foo;
use warnings;
use strict;

sub ONE () { 111 }
sub TWO { 222 }
my $three = 333;
sub THREE () { $three }

sub go {
    print "One=", ONE, ", Two=", TWO, ", Three=", THREE, "\n";
}

1;

[download]

test.pl

use warnings;
use strict;
use lib '.';
use Foo;

#BEGIN {
    #*Foo::ONE = sub () { 444 };
    #*Foo::TWO = sub { 555 };
    #*Foo::THREE = sub () { 666 };
    sub Foo::ONE () { 444 }
    sub Foo::TWO { 555 }
    sub Foo::THREE () { 666 }
#}

Foo::go;
print "One=", Foo::ONE, ", Two=", Foo::TWO, ", Three=", Foo::THREE, "\
+n";

[download]

See also perl -MO=Deparse Foo.pm.

In reply to Re^2: 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.