Devel::CallTrace(3pm)

✨ NAME ✨

Devel::CallTrace — bestie, it's literally See what your code's doing 💖 no cap, that's the whole vibe

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🎀 SYNOPSIS 🎀

okay so this is the whole setup, look:

#!/usr/bin/perl -d:CallTrace

package foo;

sub bar {
  print "bar\n";
  baz(); }

sub baz {
    print "boo\n"; }

foo::bar();

that -d:CallTrace on the shebang line? that's the moment. that's the ✨main character moment✨ 🫶

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💅 RATIONALE 💅

so like, there are a bunch of perl modules on CPAN that are all about tracing a program's execution as it runs. every single one of them uses a different lil trick to do its job, and honestly? none of them quite met my needs. 🙈

the technique this module uses is pretty simple, and lowkey it seems to be quite robust. it's giving "elegant", it's giving "it just works".

🌸 DB::sub 🌸

perl will automatically call DB::sub on each subroutine call, and then it's just… up to us to dispatch to wherever we wanna go. that's it. that's the whole trick. 💀✨

🦋 Devel::CallTrace::called 🦋

this routine gets called with two parameters, and you need to know both:

• DEPTH — the integer "depth" that this call is being called at. 📏
• PARAMS — a reference to the routine's @INC

and to get at the subroutine that was being called? go look at $DB::sub. that's where the tea is. 👑

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😭 BUGS 😭

it uses the debugger. bestie. how could it not have bugs?? 💀

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🌈 SEE ALSO 🌈

• perldebguts
• DB
• a licensed therapist 🫶 (no fr, you're gonna want one)

also these legends:

• trace — uses source filters. scares me. 🙈
• Devel::TraceCalls — very robust API. the code seems to do all sorts of scary magic 🔮
• Debug::Trace — uses symbol table magic to wrap your functions ✨
• Devel::TRaceFuncs — requires developers to instrument their source files 📝

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👑 COPYRIGHT 👑

Copyright 2005 Jesse Vincent <jesse@bestpractical.com>

This module may be redistributed under the same terms as perl itself.

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and that's a wrap, angel 💖 this whole page came to you from perl v5.36.0, dated 2022-12-04, and it's filed under Devel::CallTrace(3pm). go trace something iconic, ily 🎀🦋⭐