1Carp::Always(3) User Contributed Perl Documentation Carp::Always(3)
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6 Carp::Always - Warns and dies noisily with stack backtraces
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9 use Carp::Always;
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11 Often used on the command line:
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13 perl -MCarp::Always script.pl
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16 This module is meant as a debugging aid. It can be used to make a
17 script complain loudly with stack backtraces when warn()ing or
18 die()ing.
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20 Here are how stack backtraces produced by this module looks:
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22 # it works for explicit die's and warn's
23 $ perl -MCarp::Always -e 'sub f { die "arghh" }; sub g { f }; g'
24 arghh at -e line 1
25 main::f() called at -e line 1
26 main::g() called at -e line 1
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28 # it works for interpreter-thrown failures
29 $ perl -MCarp::Always -w -e 'sub f { $a = shift; @a = @$a };' \
30 -e 'sub g { f(undef) }; g'
31 Use of uninitialized value in array dereference at -e line 1
32 main::f('undef') called at -e line 2
33 main::g() called at -e line 2
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35 In the implementation, the Carp module does the heavy work, through
36 "longmess()". The actual implementation sets the signal hooks
37 $SIG{__WARN__} and $SIG{__DIE__} to emit the stack backtraces.
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39 Also, all uses of "carp" and "croak" are made verbose, behaving like
40 "cluck" and "confess".
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43 Carp::Always implements the following methods.
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45 import
46 Carp::Always->import()
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48 Enables Carp::Always. Also triggered by statements like
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50 use Carp::Always;
51 use Carp::Always 0.14;
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53 but not by
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55 use Carp::Always (); # does not invoke import()
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57 unimport
58 Carp::Always->unimport();
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60 Disables Carp::Always. Also triggered with
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62 no Carp::Always;
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65 This module was born as a reaction to a release of Acme::JavaTrace by
66 Sébastien Aperghis-Tramoni. Sébastien also has a newer module called
67 Devel::SimpleTrace with the same code and fewer flame comments on docs.
68 The pruning of the uselessly long docs of this module was prodded by
69 Michael Schwern.
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71 Schwern and others told me "the module name stinked" - it was called
72 "Carp::Indeed". After thinking long and getting nowhere, I went with
73 nuffin's suggestion and now it is called "Carp::Always".
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76 Carp
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78 Acme::JavaTrace and Devel::SimpleTrace
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80 Carp::Always::Color
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82 Carp::Source::Always
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84 Devel::Confess
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86 Carp::Always::SyntaxHighlightSource and Carp::Always::DieOnly
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89 · This module does not play well with other modules which fusses
90 around with "warn", "die", $SIG{__WARN__}, $SIG{__DIE__}.
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92 · Test scripts are good. I should write more of these.
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94 Please report bugs via GitHub
95 <https://github.com/aferreira/cpan-Carp-Always/issues>
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97 Backlog in CPAN RT:
98 <https://rt.cpan.org/Public/Dist/Display.html?Name=Carp-Always>
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101 Adriano Ferreira, <ferreira@cpan.org>
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104 Copyright (C) 2005-2013, 2018 by Adriano Ferreira
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106 This library is free software; you can redistribute it and/or modify it
107 under the same terms as Perl itself.
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111perl v5.28.1 2018-08-10 Carp::Always(3)