Does AUTOLOAD exist?

xevian has asked for the wisdom of the Perl Monks concerning the following question:

Hello Monks, I have a (hopefully) simple question:

I'm trying to verify if a module has an AUTOLOAD subroutine or not. I can successfully determine whether other subroutines exist using code like this:

require Test::Pkg::Thing;
my $func_name = "Test::Pkg::Thing::do_something";
if( defined &$func_name )
{
    print "defined!\n";
}
[download]

Using the same method if I try to detect if AUTOLOAD is defined, it actually tries to call Test::Pkg::Thing::AUTOLOAD even if it doesn't exist (which of course is a problem and causes the program to exit with an error.)

require Test::Pkg::Thing;
my $func_name = "Test::Pkg::Thing::AUTOLOAD";
if( defined &$func_name ) # not what I expect
{
    print "defined!\n";
}
[download]

Does any monk have a nugget of wisdom to share?

Comment on Does AUTOLOAD exist? Select or Download Code

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Re: Does AUTOLOAD exist? by rinceWind (Monsignor) on Oct 12, 2005 at 16:01 UTC
You can use 'can', even if the interface is not OO. I use this in Module::Optional `require Test::Pkg::Thing; if( Test::Pkg::Thing->can('AUTOLOAD') ) { print "can AUTOLOAD!\n"; }` [download] -- Oh Lord, won’t you burn me a Knoppix CD ? My friends all rate Windows, I must disagree. Your powers of persuasion will set them all free, So oh Lord, won’t you burn me a Knoppix CD ? (Missquoting Janis Joplin)	[reply] [d/l]
Re: Does AUTOLOAD exist? by Perl Mouse (Chaplain) on Oct 12, 2005 at 15:41 UTC
Are you sure it doesn't have an AUTOLOAD? `$ mkdir -p Test/Pkg $ echo 'package Thing; 1' > Test/Pkg/Thing.pm $ perl -w require Test::Pkg::Thing; my $func_name = "Test::Pkg::Thing::AUTOLOAD"; if( defined &$func_name ) # not what I expect { print "defined!\n"; } __END__ $` [download] No output, just as expected. `Perl --((8:>*`	[reply] [d/l]
Re^2: Does AUTOLOAD exist? by xevian (Sexton) on Oct 12, 2005 at 15:59 UTC
Actually it wasn't an issue with this code, it works. sheepish grin What was causing the issue was Carp.. I was using it to croak if the method didn't exist.. it seems it's not friendly with our code and was trying to execute the nonexistant AUTOLOAD method. Thanks :)	[reply]