How can I get a call stack listing in Perl?

perl stack-trace callstack
slashmais picture slashmais · Oct 23, 2008 · Viewed 34.5k times · Source

Is there a way I can access (for printout) a list of sub + module to arbitrary depth of sub-calls preceding a current position in a Perl script?

I need to make changes to some Perl modules (.pm's). The workflow is initiated from a web-page thru a cgi-script, passing input through several modules/objects ending in the module where I need to use the data. Somewhere along the line the data got changed and I need to find out where.

Answer

Ovid picture Ovid · Oct 23, 2008

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).

Related questions

Getting stack traces in Perl?

How do I get stack traces in Perl?

Read More
Find size of an array in Perl

I seem to have come across several different ways to find the size of an array. What is the difference between these three methods? my @arr = (2); print scalar @arr; # First way to print array size print $#arr; # Second way to …

Read More
How do I break out of a loop in Perl?

I'm trying to use a break statement in a for loop, but since I'm also using strict subs in my Perl code, I'm getting an error saying: Bareword "break" not allowed while "strict subs" in use at ./final.pl line 154. …

Read More