1Carp::Always(3) User Contributed Perl Documentation Carp::Always(3)
2
3
4
6 Carp::Always - Warns and dies noisily with stack backtraces
7
9 use Carp::Always;
10
11 Often used on the command line:
12
13 perl -MCarp::Always script.pl
14
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.
19
20 Here are how stack backtraces produced by this module looks:
21
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
27
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
34
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.
38
39 Also, all uses of "carp" and "croak" are made verbose, behaving like
40 "cluck" and "confess".
41
43 Carp::Always implements the following methods.
44
45 import
46 Carp::Always->import()
47
48 Enables Carp::Always. Also triggered by statements like
49
50 use Carp::Always;
51 use Carp::Always 0.14;
52
53 but not by
54
55 use Carp::Always (); # does not invoke import()
56
57 unimport
58 Carp::Always->unimport();
59
60 Disables Carp::Always. Also triggered with
61
62 no Carp::Always;
63
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.
70
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".
74
76 Carp
77
78 Acme::JavaTrace and Devel::SimpleTrace
79
80 Carp::Always::Color
81
82 Carp::Source::Always
83
84 Devel::Confess
85
86 Carp::Always::SyntaxHighlightSource and Carp::Always::DieOnly
87
89 • This module does not play well with other modules which fusses
90 around with "warn", "die", $SIG{__WARN__}, $SIG{__DIE__}.
91
92 • Test scripts are good. I should write more of these.
93
94 Please report bugs via GitHub
95 <https://github.com/aferreira/cpan-Carp-Always/issues>
96
97 Backlog in CPAN RT:
98 <https://rt.cpan.org/Public/Dist/Display.html?Name=Carp-Always>
99
101 Adriano Ferreira, <ferreira@cpan.org>
102
104 Copyright (C) 2005-2013, 2018 by Adriano Ferreira
105
106 This library is free software; you can redistribute it and/or modify it
107 under the same terms as Perl itself.
108
109
110
111perl v5.36.0 2023-01-20 Carp::Always(3)