diff options
Diffstat (limited to 'lib/Carp.pm')
| -rw-r--r-- | lib/Carp.pm | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/lib/Carp.pm b/lib/Carp.pm index c0cfe08d44..351f83bdf5 100644 --- a/lib/Carp.pm +++ b/lib/Carp.pm @@ -2,9 +2,12 @@ package Carp; =head1 NAME -carp - warn of errors (from perspective of caller) +carp - warn of errors (from perspective of caller) -croak - die of errors (from perspective of caller) +cluck - warn of errors with stack backtrace + (not exported by default) + +croak - die of errors (from perspective of caller) confess - die of errors with stack backtrace @@ -13,6 +16,9 @@ confess - die of errors with stack backtrace use Carp; croak "We're outta here!"; + use Carp qw(cluck); + cluck "This is how we got here!"; + =head1 DESCRIPTION The Carp routines are useful in your own modules because @@ -22,10 +28,24 @@ routine Foo() that has a carp() in it, then the carp() will report the error as occurring where Foo() was called, not where carp() was called. +=head2 Forcing a Stack Trace + +As a debugging aid, you can force Carp to treat a croak as a confess +and a carp as a cluck across I<all> modules. In other words, force a +detailed stack trace to be given. This can be very helpful when trying +to understand why, or from where, a warning or error is being generated. + +This feature is enabled by 'importing' the non-existant symbol +'verbose'. You would typically enable it by saying + + perl -MCarp=verbose script.pl + +or by including the string C<MCarp=verbose> in the L<PERL5OPT> +environment variable. + =cut -# This package implements handy routines for modules that wish to throw -# exceptions outside of the current package. +# This package is heavily used. Be small. Be fast. Be good. $CarpLevel = 0; # How many extra package levels to skip on carp. $MaxEvalLen = 0; # How much eval '...text...' to show. 0 = all. @@ -35,6 +55,19 @@ $MaxArgNums = 8; # How many arguments to print. 0 = all. require Exporter; @ISA = Exporter; @EXPORT = qw(confess croak carp); +@EXPORT_OK = qw(cluck verbose); +@EXPORT_FAIL = qw(verbose); # hook to enable verbose mode + +sub export_fail { + shift; + if ($_[0] eq 'verbose') { + local $^W = 0; + *shortmess = \&longmess; + shift; + } + return @_; +} + sub longmess { my $error = join '', @_; @@ -138,5 +171,6 @@ sub shortmess { # Short-circuit &longmess if called via multiple packages sub confess { die longmess @_; } sub croak { die shortmess @_; } sub carp { warn shortmess @_; } +sub cluck { warn longmess @_; } 1; |