|Perl: the Markov chain saw|
Re: RFC: Basic debugging checklistby jplindstrom (Monsignor)
|on Feb 19, 2009 at 01:30 UTC||Need Help??|
Use the Carp module to show you the stack trace, i.e. each sub routine call in the source code from which you started the program to where you are printing the debug output. Carp comes with Perl.
Carp on search.cpan.org appears to identify perl itself and doesn't provide POD for some reason, but see: perldoc Carp.
Another useful module is Carp::Always, which makes all dies and warns emit stack traces.
Note that this will change exception strings, so any eval BLOCK that checks for specific exception matches against $@ may fail because of this.
Enable Carp::Always with a regular "use" statement in the code, or temporarily from the command line using one of these:
Or from within Emacs using the M-x setenv function. This is useful if you run Perl programs using the *compilation* mode.