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Sub::Identify - Retrieve names of code references


    use Sub::Identify ':all';
    my $subname = sub_name( $some_coderef );
    my $packagename = stash_name( $some_coderef );
    # or, to get all at once...
    my $fully_qualified_name = sub_fullname( $some_coderef );
    defined $subname
        and say "this coderef points to sub $subname in package $packagename";
    my ($file, $line) = get_code_location( $some_coderef );
        and say "this coderef is defined at line $line in file $file";
    is_sub_constant( $some_coderef )
        and say "this coderef points to a constant subroutine";


Sub::Identify allows you to retrieve the real name of code references.

It provides six functions, all of them taking a code reference.

sub_name returns the name of the code reference passed as an argument (or __ANON__ if it's an anonymous code reference), stash_name returns its package, and sub_fullname returns the concatenation of the two.

get_code_info returns a list of two elements, the package and the subroutine name (in case of you want both and are worried by the speed.)

In case of subroutine aliasing, those functions always return the original name.

get_code_location returns a two-element list containing the file name and the line number where the subroutine has been defined.

is_sub_constant returns a boolean value indicating whether the subroutine is a constant or not.

Pure-Perl version

By default Sub::Identify tries to load an XS implementation of the get_code_info, get_code_location and (on perl versions 5.16.0 and later) is_sub_constant functions, for speed; if that fails, or if the environment variable PERL_SUB_IDENTIFY_PP is defined to a true value, it will fall back to a pure perl implementation, that uses perl's introspection mechanism, provided by the B module.


Sub::Util, part of the module distribution Scalar::List::Utils since version 1.40. Since this will be a core module starting with perl 5.22.0, it is encouraged to migrate to Sub::Util when possible.



A git repository for the sources is at


(c) Rafael Garcia-Suarez (rgs at consttype dot org) 2005, 2008, 2012, 2014, 2015

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