print variable name not by hash but ref?

[Ela]

some day i read a book telling that it may be useful to print a variable
name for debugging purpose. since i was new that moment, i just skipped it.
now when i want to use this feature, i no longer get back where it is.
google search using perl and "print variable name" does not return good
results. And I am not going to use hash because i just want to debug, e..g.
I expect

$var1 = 3;
$ALongVariable = "hahahaha";

debug($var1);
debug($ALongVariable);

sub debug {
$dvar = shift;
some more codes here?
print $dvar;
print "\n";
}

=======
to print out:

$var1 : 3
$ALongVariable : hahahaha

Could anybody help?

[A. Sinan Unur]

"Ela" <e...@yantai.org> wrote in
news:fssqc1$3f7$1...@ijustice.itsc.cuhk.edu.hk:

> some day i read a book telling that it may be useful to print a
> variable name for debugging purpose. since i was new that moment,
> i just skipped it.

The closest thing I know of is

http://search.cpan.org/~robin/PadWalker-1.7/PadWalker.pm

Read the docs, especially the warnings.

Sinan

--
A. Sinan Unur <1u...@llenroc.ude.invalid>
(remove .invalid and reverse each component for email address)

comp.lang.perl.misc guidelines on the WWW:
http://www.rehabitation.com/clpmisc/

[smallpond]

That can't work since only the value is passed to your
debug sub, not the variable.

You can get to package variables through the symbol table
but I don't know how to get to lexicals.

perl -e 'our $foo=5; print join "\n", keys %main::;' |grep foo
foo

perl -e 'my $foo=5; print join "\n", keys %main::;' |grep foo
<== no package variable named 'foo'