.\" Automatically generated by Pod::Man 4.10 (Pod::Simple 3.35) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Carp::Clan 3pm" .TH Carp::Clan 3pm "2018-12-21" "perl v5.28.1" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Carp::Clan \- Report errors from perspective of caller of a "clan" of modules .SH "VERSION" .IX Header "VERSION" version 6.07 .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& carp \- warn of errors (from perspective of caller) \& \& cluck \- warn of errors with stack backtrace \& \& croak \- die of errors (from perspective of caller) \& \& confess \- die of errors with stack backtrace \& \& use Carp::Clan qw(^MyClan::); \& croak "We\*(Aqre outta here!"; \& \& use Carp::Clan; \& confess "This is how we got here!"; .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" This module is based on "\f(CW\*(C`Carp.pm\*(C'\fR\*(L" from Perl 5.005_03. It has been modified to skip all package names matching the pattern given in the \*(R"use\*(L" statement inside the \*(R"\f(CW\*(C`qw()\*(C'\fR" term (or argument list). .PP Suppose you have a family of modules or classes named \*(L"Pack::A\*(R", \&\*(L"Pack::B\*(R" and so on, and each of them uses "\f(CW\*(C`Carp::Clan qw(^Pack::);\*(C'\fR" (or at least the one in which the error or warning gets raised). .PP Thus when for example your script \*(L"tool.pl\*(R" calls module \*(L"Pack::A\*(R", and module \*(L"Pack::A\*(R" calls module \*(L"Pack::B\*(R", an exception raised in module \*(L"Pack::B\*(R" will appear to have originated in \*(L"tool.pl\*(R" where \&\*(L"Pack::A\*(R" was called, and not in \*(L"Pack::A\*(R" where \*(L"Pack::B\*(R" was called, as the unmodified "\f(CW\*(C`Carp.pm\*(C'\fR" would try to make you believe \f(CW\*(C`:\-)\*(C'\fR. .PP This works similarly if \*(L"Pack::B\*(R" calls \*(L"Pack::C\*(R" where the exception is raised, et cetera. .PP In other words, this blames all errors in the "\f(CW\*(C`Pack::*\*(C'\fR" modules on the user of these modules, i.e., on you. \f(CW\*(C`;\-)\*(C'\fR .PP 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 \f(CW@ISA\fR \&\- as in the original "\f(CW\*(C`Carp.pm\*(C'\fR" module \- doesn't help). .PP The purpose and advantage of this is that a \*(L"clan\*(R" 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. .PP In case you just want to ward off all error messages from the module in which you "\f(CW\*(C`use Carp::Clan\*(C'\fR\*(L", 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 \*(R"\f(CW\*(C`use Carp;\*(C'\fR" for \f(CW\*(C`;\-)\*(C'\fR), instead of in your module itself (which is what you can do with a \&\*(L"die\*(R" or \*(L"warn\*(R" anyway), you do not need to provide a pattern, the module will automatically provide the correct one for you. .PP I.e., just "\f(CW\*(C`use Carp::Clan;\*(C'\fR\*(L" without any arguments and call \*(R"carp\*(L" or \*(R"croak" as appropriate, and they will automatically defend your module against all blames! .PP 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. .SS "Forcing a Stack Trace" .IX Subsection "Forcing a Stack Trace" As a debugging aid, you can force "\f(CW\*(C`Carp::Clan\*(C'\fR\*(L" to treat a \*(R"croak\*(L" as a \*(R"confess\*(L" and a \*(R"carp\*(L" as a \*(R"cluck". 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. .PP This feature is enabled either by \*(L"importing\*(R" the non-existent symbol \&'verbose', or by setting the global variable "\f(CW$Carp::Clan::Verbose\fR" to a true value. .PP You would typically enable it by saying .PP .Vb 1 \& use Carp::Clan qw(verbose); .Ve .PP Note that you can both specify a \*(L"family pattern\*(R" and the string \*(L"verbose\*(R" inside the "\f(CW\*(C`qw()\*(C'\fR\*(L" term (or argument list) of the \*(R"use\*(L" statement, but consider that a pattern of packages to skip is pointless when \*(R"verbose" causes a full stack trace anyway. .SH "BUGS" .IX Header "BUGS" The "\f(CW\*(C`Carp::Clan\*(C'\fR\*(L" routines don't handle exception objects currently. If called with a first argument that is a reference, they simply call \*(R"\f(CW\*(C`die()\*(C'\fR\*(L" or \*(R"\f(CW\*(C`warn()\*(C'\fR", as appropriate. .PP Bugs may be submitted through the \s-1RT\s0 bug tracker (or bug\-Carp\-Clan@rt.cpan.org ). .SH "AUTHOR" .IX Header "AUTHOR" Steffen Beyer .SH "CONTRIBUTORS" .IX Header "CONTRIBUTORS" .IP "\(bu" 4 Joshua ben Jore .IP "\(bu" 4 Karen Etheridge .IP "\(bu" 4 Kent Fredric .SH "COPYRIGHT AND LICENSE" .IX Header "COPYRIGHT AND LICENSE" This software is copyright (c) 2001 by Steffen Beyer, Joshua ben Jore. .PP This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.