Perl – How to get the name of the current subroutine in Perl

perl

In Perl we can get the name of the current package and current line number Using the predefined variables like __PACKAGE__ and __LINE__.

Like this I want to get the name of the current subroutine:

use strict;
use warnings;

print __PACKAGE__;
sub test()
{
    print __LINE__;
}
&test();

In the above code I want to get the name of the subroutine inside the function test.

Best Answer

Use the caller() function:

my $sub_name = (caller(0))[3];

This will give you the name of the current subroutine, including its package (e.g. 'main::test'). Closures return names like 'main::__ANON__'and in eval it will be '(eval)'.

Related Solutions

Perl – How to get a call stack listing in Perl

You can use Devel::StackTrace.

use Devel::StackTrace;
my $trace = Devel::StackTrace->new;
print $trace->as_string; # like carp

It behaves like Carp's trace, but you can get more control over the frames.

The one problem is that references are stringified and if a referenced value changes, you won't see it. However, you could whip up some stuff with PadWalker to print out the full data (it would be huge, though).

Perl – How to elegantly call a Perl subroutine whose name is held in a variable

Rather than storing subroutine names in a variable and calling them, a better way to do this is to use a hash of subroutine references (otherwise known as a dispatch table.)

my %actions = ( foo => \&foo,
                bar => \&bar,
                baz => sub { print 'baz!' } 
                ... 
              );

Then you can call the right one easily:

$actions{$action}->();

You can also add some checking to make sure $action is a valid key in the hash, and so forth.

In general, you should avoid symbolic references (what you're doing now) as they cause all kinds of problems. In addition, using real subroutine references will work with strict turned on.

Best Answer

Related Solutions

Perl – How to get a call stack listing in Perl

Perl – How to elegantly call a Perl subroutine whose name is held in a variable

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