X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCarp.pm;h=5dbae299fdbd11d1218e52a2fdbd1b20e0c7d144;hb=917211f59b1d5210f3944956e717bae1a2ca7565;hp=4ceecda23a453326bb498d2c88917f2d226f2605;hpb=1129fd022cb7a362c2ea03105d1a4b2127589595;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/Carp.pm b/lib/Carp.pm index 4ceecda..5dbae29 100644 --- a/lib/Carp.pm +++ b/lib/Carp.pm @@ -13,6 +13,10 @@ croak - die of errors (from perspective of caller) confess - die of errors with stack backtrace +shortmess - return the message that carp and croak produce + +longmess - return the message that cluck and confess produce + =head1 SYNOPSIS use Carp; @@ -21,19 +25,22 @@ confess - die of errors with stack backtrace use Carp qw(cluck); cluck "This is how we got here!"; + print FH Carp::shortmess("This will have caller's details added"); + print FH Carp::longmess("This will have stack backtrace added"); + =head1 DESCRIPTION The Carp routines are useful in your own modules because they act like die() or warn(), but with a message which is more likely to be useful to a user of your module. In the case of -cluck and confess that context is a summary of every -call in the call-stack. For a shorter message you can use carp -or croak which try to report the error as being from where +cluck, confess, and longmess that context is a summary of every +call in the call-stack. For a shorter message you can use carp, +croak or shortmess which report the error as being from where your module was called. There is no guarantee that that is where the error was, but it is a good educated guess. -Here is a more complete description of how the shorter message works. -What it does is search the call-stack for a function call stack where +Here is a more complete description of how shortmess works. What +it does is search the call-stack for a function call stack where it hasn't been told that there shouldn't be an error. If every call is marked safe, it then gives up and gives a full stack backtrace instead. In other words it presumes that the first likely @@ -69,7 +76,7 @@ this practice is discouraged.) =item 5. Any call to Carp is safe. (This rule is what keeps it from -reporting the error where you call carp or croak.) +reporting the error where you call carp/croak/shortmess.) =back @@ -124,19 +131,19 @@ $Verbose = 0; # If true then make shortmess call longmess instead require Exporter; @ISA = ('Exporter'); @EXPORT = qw(confess croak carp); -@EXPORT_OK = qw(cluck); - -# we handle verbose usage ("perl -MCarp=verbose script.pl") ourselves -# and then erase all traces of this call so that Exporter doesn't -# know that we have been here. BTW subclasses shouldn't try to -# do anything useful with 'verbose', including have that be their -# name... -sub import { - if (grep 'verbose' eq $_, @_) { - @_ = grep 'verbose' ne $_, @_; - $Verbose = "verbose"; - } - goto &Exporter::import; +@EXPORT_OK = qw(cluck verbose longmess shortmess); +@EXPORT_FAIL = qw(verbose); # hook to enable verbose mode + + +# if the caller specifies verbose usage ("perl -MCarp=verbose script.pl") +# then the following method will be called by the Exporter which knows +# to do this thanks to @EXPORT_FAIL, above. $_[1] will contain the word +# 'verbose'. + +sub export_fail { + shift; + $Verbose = shift if $_[0] eq 'verbose'; + return @_; }