1Fatal(3) User Contributed Perl Documentation Fatal(3)
2
6 Fatal - Replace functions with equivalents which succeed or die
7
9 use Fatal qw(open close);
10 open(my $fh, "<", $filename); # No need to check errors!
12 use File::Copy qw(move);
14 use Fatal qw(move);
15 move($file1, $file2); # No need to check errors!
17 sub juggle { . . . }
19 Fatal->import('juggle');
20
22 Fatal has been obsoleted by the new autodie pragma. Please use autodie
23 in preference to "Fatal". autodie supports lexical scoping, throws
24 real exception objects, and provides much nicer error messages.
25 The use of ":void" with Fatal is discouraged.
27
29 "Fatal" provides a way to conveniently replace functions which normally
30 return a false value when they fail with equivalents which raise
31 exceptions if they are not successful. This lets you use these
32 functions without having to test their return values explicitly on each
33 call. Exceptions can be caught using "eval{}". See perlfunc and
34 perlvar for details.
35 The do-or-die equivalents are set up simply by calling Fatal's "import"
37 routine, passing it the names of the functions to be replaced. You may
38 wrap both user-defined functions and overridable CORE operators (except
39 "exec", "system", "print", or any other built-in that cannot be
40 expressed via prototypes) in this way.
41 If the symbol ":void" appears in the import list, then functions named
43 later in that import list raise an exception only when these are called
44 in void context--that is, when their return values are ignored. For
45 example
46 use Fatal qw/:void open close/;
48 # properly checked, so no exception raised on error
50 if (not open(my $fh, '<', '/bogotic') {
51 warn "Can't open /bogotic: $!";
52 }
53 # not checked, so error raises an exception
55 close FH;
56 The use of ":void" is discouraged, as it can result in exceptions not
58 being thrown if you accidentally call a method without void context.
59 Use autodie instead if you need to be able to disable autodying/Fatal
60 behaviour for a small block of code.
61
63 Bad subroutine name for Fatal: %s
64 You've called "Fatal" with an argument that doesn't look like a
65 subroutine name, nor a switch that this version of Fatal
66 understands.
67 %s is not a Perl subroutine
69 You've asked "Fatal" to try and replace a subroutine which does not
70 exist, or has not yet been defined.
71 %s is neither a builtin, nor a Perl subroutine
73 You've asked "Fatal" to replace a subroutine, but it's not a Perl
74 built-in, and "Fatal" couldn't find it as a regular subroutine. It
75 either doesn't exist or has not yet been defined.
76 Cannot make the non-overridable %s fatal
78 You've tried to use "Fatal" on a Perl built-in that can't be
79 overridden, such as "print" or "system", which means that "Fatal"
80 can't help you, although some other modules might. See the "SEE
81 ALSO" section of this documentation.
82 Internal error: %s
84 You've found a bug in "Fatal". Please report it using the
85 "perlbug" command.
86
88 "Fatal" clobbers the context in which a function is called and always
89 makes it a scalar context, except when the ":void" tag is used. This
90 problem does not exist in autodie.
91 "Used only once" warnings can be generated when "autodie" or "Fatal" is
93 used with package filehandles (eg, "FILE"). It's strongly recommended
94 you use scalar filehandles instead.
95
97 Original module by Lionel Cons (CERN).
98 Prototype updates by Ilya Zakharevich <ilya@math.ohio-state.edu>.
100 autodie support, bugfixes, extended diagnostics, "system" support, and
102 major overhauling by Paul Fenwick <pjf@perltraining.com.au>
103
105 This module is free software, you may distribute it under the same
106 terms as Perl itself.
107
109 autodie for a nicer way to use lexical Fatal.
110 IPC::System::Simple for a similar idea for calls to "system()" and
112 backticks.
113perl v5.16.3 2013-02-22 Fatal(3)