It will be defined in __PACKAGE__ - the current package.

update: The normal behaviour would be to define the method in the current object's namespace, but you are overriding this with  s/^.*:://.

update: see rir explanation below, then come back to this example.

An example:

package One;

sub AUTOLOAD {
    my $name = $AUTOLOAD;
    $name =~ s/^.*:://;
    *$name = sub { print "called $name inside ",__PACKAGE__,"\n" };
    goto &$name;
  }

package Two;
@ISA = qw(One);

package Main;

One->try1();
Two->try2();
$a = bless {}, Two;
$a->try3();
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output:

called try1 inside One
called try2 inside One
called try3 inside One
called DESTROY inside One
[download]

update: more interesting example

This shoudl show you: it's in the package that AUTOLOAD is defined in.

#!/bin/perl -w
use strict;

my $obj= foo->new;
$obj->toto();
foo::toto();
toto(); # dies an horrible death!

package foo; 

use vars qw($AUTOLOAD);

sub new { return bless {}; }

sub AUTOLOAD {
    my $name = $AUTOLOAD;
    $name =~ s/^.*:://;
    no strict 'refs';
    *$name = sub { print "in $name\n"; };
    goto &$name;
  }
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AUTOLOAD is called only after the entire inheritance tree has been checked for the method. first the tree is searched in "left-most parent wins" order for the method. then the tree is searched for an AUTOLOAD in the same order.

so if you have:

package A;

...
sub AUTOLOAD {

}

package B;
@ISA = qw(A);
...

package main;
my $object = new B();

$object->method();
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it will look at B for method(), then it will look at A for method(), then it will look for an AUTOLOAD in B, then finally it will look for an AUTOLOAD in A.

anders pearson

This is also the namespace in
which the created routine exists. This is because you stripped
off the explicit package name. You could specify the namespace
if you wish. Why? Efficiency maybe. Caching the
creations of AUTOLOAD is often a reasonable idea.
But pushing the result back down the inheritance tree
may not be reasonable.

In an AUTOLOAD sub you should usually avoid handling routines
that have a name in all uppercase. Perl has special functions
like DESTROY, these subs are all named in all caps.

Also isn't the goto pointless.

The goto after AUTOLOAD is a shortcut, so that you don't have to make a new stack frame, etc, when you pass control to the new method.

update:oops. This was a response to node 200692 but something went wrong with the links. thanks footpad

Edited: ~Wed Sep 25 22:30:46 2002 (GMT) by footpad: Reparented, per Consideration.

In my tests a goto &rout is slower than a plain rout.

I don't usually care much about micro-optimizations, but
given that AUTOLOAD is a slug, it seems a bad time to
imply that an arcane construct is faster than a normal call.