Devel::ArgNames(3pm)

💖 Devel::ArgNames 💖

okay bestie, welcome to Devel::ArgNames — it's a Perl module (a 3pm page, we love that for it), it lives in the User Contributed Perl Documentation, and it does exactly one gorgeous thing: it figures out the names of variables passed into subroutines. that's the whole vibe. 🎀

---

✨ NAME ✨

Devel::ArgNames — figure out the names of variables passed into subroutines. no cap, that's it, that's the job.

---

🌸 SYNOPSIS 🌸

use Devel::ArgNames;

sub foo {
    warn "foo() called with arguments: "
        . join(", ", map { defined() ? $_ : "<unknown>" } arg_names(@_) );
}

foo($bar, $gorch, $blah[4]);

so like. you call arg_names(@_) and it just knows what the variables were called at the call site. it's giving psychic. 🔮

---

🦋 DESCRIPTION 🦋

okay so when you're print-debugging (we've all been there, no shame), you will often find yourself writing stuff like:

print "\$foo is $foo, \$bar is $bar"

and honestly? manually escaping all those \$ sigils is so tedious. exhausting. not the move. 😭

with this module you can just write a reusable subroutine instead, effortlessly:

sub my_print_vars {
    my %vars;

    @vars{arg_names()} = @_;

    foreach my $var ( keys %vars ) {
        warn "$var is $vars{$var}\n";
    }
}

my_print_vars($foo, $bar);

look at that. the variable names come for free from the caller's arguments. iconic behavior. 👑

real talk though: this module doesn't provide dumping facilities, because there are way too many of those to choose from and it's not about to pick favorites. it's a DIY kit ;-) so you build your own little printer and it hands you the names.

---

💅 EXPORTS 💅

• arg_names [ $level ] — this function returns the names associated with the variables it finds on @_, at the level $level. and if you don't pass $level? then arg_names's caller's caller gets used — which is the $level == 2 case, for the people keeping score. 💯

---

🧚 VERSION CONTROL 🧚

this module is maintained using Darcs. you can grab the latest version from http://nothingmuch.woobling.org/Devel-ArgNames/, and use darcs send to commit changes. old school but it works, okay? 🫶

---

🔥 SEE ALSO 🔥

• Data::Dumper::Simple
• DB
• Devel::Caller
• Devel::Caller::Perl
• PadWalker

go read those too, they're the friend group. 🌈

---

👑 AUTHORS 👑

• Ran Eilam
• Yuval Kogman <nothingmuch@woobling.org>

---

📜 COPYRIGHT 📜

Copyright (c) 2007 Yuval Kogman. All rights reserved
This program is free software; you can redistribute
it and/or modify it under the same terms as Perl itself.

---

okay and that's the whole page, bestie!! this little write-up is Devel::ArgNames(3pm), sitting in the User Contributed Perl Documentation, and the version living down at the bottom of the original is perl v5.36.0 from 2022-12-06. mwah. slay. periodt. 💖✨🎀