• NAME
• VERSION
• SYNOPSIS
• DESCRIPTION
  • EXPORT
• ACKNOWLEDGMENTS
• SEE ALSO
• BUGS
• AUTHOR
• COPYRIGHT AND LICENSE

NAME

Demeter::Carp - Warns and dies noisily with stack backtraces and ANSIColor markup

VERSION

This documentation refers to Demeter version 0.9.26.

SYNOPSIS

  use Demeter::Carp;

This is a small modification of the very useful Carp::Always module by Adriano R. Ferreira.

Like Carp::Always, it makes every warn() and die() complain loudly in the calling package and elsewhere. It also applies some color to the user-supplied part of the message so that it stands out from the stack trace in a command line script. This is really only useful in the context of Demeter as it makes specific reference to the Demeter::Mode object.

This plays with GUI apps like Artemis because they overwrite $SIG{__WARN__} and $SIG{__DIE__} appropriately for a GUI.

The rest of this documentation is copied verbatim from Carp::Always.

More often used on the command line:

  perl -MCarp::Always script.pl

DESCRIPTION

This module is meant as a debugging aid. It can be used to make a script complain loudly with stack backtraces when warn()ing or die()ing.

Here are how stack backtraces produced by this module looks:

  # it works for explicit die's and warn's
  $ perl -MCarp::Always -e 'sub f { die "arghh" }; sub g { f }; g'
  arghh at -e line 1
          main::f() called at -e line 1
          main::g() called at -e line 1

  # it works for interpreter-thrown failures
  $ perl -MCarp::Always -w -e 'sub f { $a = shift; @a = @$a };' \
                           -e 'sub g { f(undef) }; g'
  Use of uninitialized value in array dereference at -e line 1
          main::f('undef') called at -e line 2
          main::g() called at -e line 2

In the implementation, the Carp module does the heavy work, through longmess(). The actual implementation sets the signal hooks $SIG{__WARN__} and $SIG{__DIE__} to emit the stack backtraces.

Oh, by the way, carp and croak when requiring/using the Carp module are also made verbose, behaving like cloak and confess, respectively.

EXPORT

Nothing at all is exported.

ACKNOWLEDGMENTS

This module was born as a reaction to a release of Acme::JavaTrace by E9bastien Aperghis-Tramoni. E9bastien also has a newer module called Devel::SimpleTrace with the same code and fewer flame comments on docs. The pruning of the uselessly long docs of this module were prodded by Michael Schwern.

Schwern and others told me "the module name stinked" - it was called Carp::Indeed. After thinking long and not getting nowhere, I went with nuffin's suggestion and now it is called Carp::Always. Carp::Indeed which is now deprecate lives in its own distribution (which won't go anywhere but will stay there as a redirection to this module).

SEE ALSO

• <Carp>

• Acme::JavaTrace and Devel::SimpleTrace

Please report bugs via CPAN RT http://rt.cpan.org/NoAuth/Bugs.html?Dist=Carp-Always.

BUGS

Every (un)deserving module has its own pet bugs.

This module does not play well with other modules which fusses around with warn, die, $SIG{'__WARN__'}, $SIG{'__DIE__'}.

*

Test scripts are good. I should write more of these.

*

I don't know if this module name is still a bug as it was at the time of Carp::Indeed.

AUTHOR

Adriano Ferreira, <ferreira@cpan.org>

COPYRIGHT AND LICENSE

Carp::Always is Copyright (C) 2005-2007 by Adriano R. Ferreira

ANSIColor addition by Bruce Ravel 2014

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.