Perl6::Caller(3) OO caller() interface


Version 0.04


use Perl6::Caller;
my $sub = caller->subroutine;
my $line_number = caller->line;
my $is_require = caller(3)->is_require;



 # standard usage
 print "In ",           caller->subroutine,
       " called from ", caller->file,
       " line ",        caller->line;
 # get a caller object
 my $caller = caller;
 my $caller = caller();   # same thing
 # get a caller object for a different stack from
 my $caller = caller(2);  # two stack frames up
 print $caller->package;  # prints the package name
 # enjoy the original flavor
 my @caller = caller;     # original caller behavior
 print $caller[0],        # prints the package name


This module is experimental. It's also alpha. Bug reports and patches welcome.

By default, this module exports the "caller" function. This automatically returns a new "caller" object. An optional argument specifies how many stack frames back to skip, just like the "CORE::caller" function. This lets you do things like this:

 print "In ",           caller->subroutine,
       " called from ", caller->file,
       " line ",        caller->line;

If you do not wish the "caller" function imported, specify an empty import list and instantiate a new "Perl6::Caller" object.

 use Perl6::Caller ();
 my $caller = Perl6::Caller->new;
 print $caller->line;

Note: if the results from the module seem strange, please read perldoc -s caller carefully. It has stranger behavior than you might be aware.


The following methods are available on the "caller" object. They return the same values as documented in perldoc -f caller.

There are no "hints" and "bitmask" methods because those are documented as for internal use only.

  • "package"
  • "filename"
  • "line"
  • "subroutine"
  • "hasargs"
  • "wantarray"
  • "evaltext"
  • "is_require"

Note that each of these values will report correctly for when the caller object was created. For example, the following will probably print different line numbers:

 print caller->line;
 sub foo { 
    print caller->line;

However, the following will print the same line numbers:

 my $caller = Perl6::Caller->new;   # everything is relative to here
 print $caller->line;
 sub foo { 
    my $caller = shift;
    print $caller->line;


Most of the time, this package should just work and not interfere with anything else.
  • $hints, $bitmask

    'hints' and 'bitmask' are not available. They are documented to be for internal use only and should not be relied upon. Further, the bitmask caused strange test failures, so I opted not to include them.

  • Subclassing


  • Perl 6

    I'm not entirely comfortable with the namespace. The Perl 6 caller actually does considerably more, but for me to have a hope of working that in, I need proper introspection and I don't have that. Thus, I've settled for simply having a caller object.

  • *CORE::GLOBAL::caller

    I didn't implement this, though I was tempted. It turns out to be a bit tricky in spots and I'm very concerned about globally overriding behavior. I might change my mind in the future if there's enough demand.

  • Overloading

    In string context, this returns the package name. This is to support the original "caller" behavior.

  • List Context

    In list context, we simply default to the original behavior of "CORE::caller". However, this always assumes we've called caller with an argument. Calling "caller" and caller(0) are identical with this module. It's difficult to avoid since the stack frame changes.


Curtis ``Ovid'' Poe, "<[email protected]>"


Thanks to "phaylon" for helping me revisit a bad design issue with this.


Please report any bugs or feature requests to "[email protected]", or through the web interface at <>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.



Copyright 2007 Curtis ``Ovid'' Poe, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.