passing a variables name to a subroutine

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

Hi Monks,
for a debugging-sub I would like to pass the name of a variable to the sub. How is this possible?

What I have so far (untested yet):

say sdump($some_ref);

sub sdump {
    my $ref = shift || croak('nothing to dump - missing ref');
    my $depth = shift || 2;
    local $Data::Dumper::Maxdepth = $depth;
    return 'Dump of $var_name: ' . "\n" . Dumper($ref)
}
[download]

How can I get the $var_name('$some_ref' in this exemple) into the sub?

Comment on passing a variables name to a subroutine Download Code

Replies are listed 'Best First'.
Re: passing a variables name to a subroutine by moritz (Cardinal) on Feb 18, 2011 at 12:13 UTC
for a debugging-sub I would like to pass the name of a variable to the sub. How is this possible? `my $x; yoursub '$x';` [download] Inside your sub you can use PadWalker to access foreign lexical variables, and caller plus symbol table magic for package variables. Perl 6 - second systems done right	[reply] [d/l]
Re^2: passing a variables name to a subroutine by LANTI (Sexton) on Feb 18, 2011 at 13:55 UTC
hmh ... seems not to work, if the dumped ref is a lexical variable in production-code. For the moment I live with this solution - not very elegant, because most of the time the identifying string will be same as the var-name: `say sdump($pout, '$pout'); sub sdump { my $ref = shift \|\| croak('nothing to dump - missing ref'); my $name = shift \|\| 'n/a'; my $depth = shift \|\| 2; local $Data::Dumper::Maxdepth = $depth; return "Dump of $name:\n" . Dumper($ref); }` [download] Any idea, how to call it this way? `sdump('$pout');` [download]	[reply] [d/l] [select]
Re^3: passing a variables name to a subroutine by moritz (Cardinal) on Feb 18, 2011 at 15:23 UTC
hmh ... seems not to work, if the dumped ref is a lexical variable in production-code. With which code did it not work? Did you try PadWalker as I suggested? How the the production code differ from the test code? Perl 6 - second systems done right	[reply]
Re^2: passing a variables name to a subroutine by jdporter (Paladin) on Jul 19, 2012 at 15:40 UTC
Congrats on winning 888888. :-)	[reply]
Re: passing a variables name to a subroutine by Anonymous Monk on Feb 18, 2011 at 14:14 UTC
Displaying a variable's name and value in a sub	[reply]