==================================== Package "Carp::Clan" ==================================== Abstract: --------- This module reports errors from the perspective of the caller of a "clan" of modules, similar to "Carp.pm" itself. But instead of giving it a number of levels to skip on the calling stack, you give it a pattern to characterize the package names of the "clan" of modules which shall never be blamed for any error. :-) So these modules stick together like a "clan" and any error which occurs will be blamed on the "outsider" script or modules not belonging to this "clan". Prerequisites: -------------- Perl version 5.005_03 or higher. (Should probably also work with older versions of Perl, however.) Installation: ------------- As usual: perl Makefile.PL make make test make install Changes over previous versions: ------------------------------- Please refer to the file "CHANGES.txt" in this distribution for a more detailed version history log. Documentation: -------------- The documentation of this package is included in POD format (= "Plain Old Documentation") in the file with the extension ".pod" in this distribution, the human-readable markup-language standard for Perl documentation. By building this package, this documentation will automatically be converted into a man page, which will automatically be installed in your Perl tree for further reference through the installation process, where it can be accessed by the commands "man Carp::Clan" (Unix) and "perldoc Carp::Clan" (Unix and Win32 alike), for example. What does it do: ---------------- This module is based on "Carp.pm" from Perl 5.005_03. It has been modified to skip all package names matching the pattern given in the "use" statement inside the "qw()" term (or argument list). Suppose you have a family of modules or classes named "Pack::A", "Pack::B" and so on, and each of them uses "Carp::Clan qw(^Pack::);" (or at least the one in which the error or warning gets raised). Thus when for example your script "tool.pl" calls module "Pack::A", and module "Pack::A" calls module "Pack::B", an exception raised in module "Pack::B" will appear to have originated in "tool.pl" where "Pack::A" was called, and not in "Pack::A" where "Pack::B" was called, as the unmodified "Carp.pm" would try to make you believe :-). This works similarly if "Pack::B" calls "Pack::C" where the exception is raised, etcetera. In other words, this blames all errors in the "Pack::*" modules on the user of these modules, i.e., on you. ;-) The skipping of a clan (or family) of packages according to a pattern describing its members is necessary in cases where these modules are not classes derived from each other (and thus when examining "@ISA" - as in the original "Carp.pm" module - doesn't help). The purpose and advantage of this is that a "clan" of modules can work together (and call each other) and throw exceptions at various depths down the calling hierarchy and still appear as a monolithic block (as though they were a single module) from the perspective of the caller. In case you just want to ward off all error messages from the module in which you "use Carp::Clan", i.e., if you want to make all error messages or warnings to appear to originate from where your module was called (this is what you usually used to "use Carp;" for ;-) ), instead of in your module itself (which is what you can do with a "die" or "warn" anyway), you do not need to provide a pattern, the module will automatically provide the correct one for you. I.e., just "use Carp::Clan;" without any arguments and call "carp" or "croak" as appropriate, and they will automatically defend your module against all blames! In other words, a pattern is only necessary if you want to make several modules (more than one) work together and appear as though they were only one. Author's note: -------------- If you have any questions, suggestions or need any assistance, please let me know! Please do send feedback, this is essential for improving this module according to your needs! I hope you will find this module useful. Enjoy! Yours, -- Steffen Beyer http://www.engelschall.com/u/sb/ "There is enough for the need of everyone in this world, but not for the greed of everyone." - Mohandas Karamchand "Mahatma" Gandhi