Fatal - Replace functions with equivalents which succeed or die
- use Fatal qw(open close);
- open(my $fh, "<", $filename); # No need to check errors!
- use File::Copy qw(move);
- use Fatal qw(move);
- move($file1, $file2); # No need to check errors!
- sub juggle { . . . }
- Fatal->import('juggle');
Fatal has been obsoleted by the new autodie pragma. Please use
autodie in preference to Fatal
. autodie supports lexical scoping,
throws real exception objects, and provides much nicer error messages.
The use of :void
with Fatal is discouraged.
Fatal
provides a way to conveniently replace
functions which normally return a false value when they fail with
equivalents which raise exceptions if they are not successful. This
lets you use these functions without having to test their return
values explicitly on each call. Exceptions can be caught using
eval{}. See perlfunc and perlvar for details.
The do-or-die equivalents are set up simply by calling Fatal's
import routine, passing it the names of the functions to be
replaced. You may wrap both user-defined functions and overridable
CORE operators (except exec, system, print, or any other
built-in that cannot be expressed via prototypes) in this way.
If the symbol :void
appears in the import list, then functions
named later in that import list raise an exception only when
these are called in void context--that is, when their return
values are ignored. For example
- use Fatal qw/:void open close/;
- # properly checked, so no exception raised on error
- if (not open(my $fh, '<', '/bogotic') {
- warn "Can't open /bogotic: $!";
- }
- # not checked, so error raises an exception
- close FH;
The use of :void
is discouraged, as it can result in exceptions
not being thrown if you accidentally call a method without
void context. Use autodie instead if you need to be able to
disable autodying/Fatal behaviour for a small block of code.
You've called Fatal
with an argument that doesn't look like
a subroutine name, nor a switch that this version of Fatal
understands.
You've asked Fatal
to try and replace a subroutine which does not
exist, or has not yet been defined.
You've asked Fatal
to replace a subroutine, but it's not a Perl
built-in, and Fatal
couldn't find it as a regular subroutine.
It either doesn't exist or has not yet been defined.
You've tried to use Fatal
on a Perl built-in that can't be
overridden, such as print or system, which means that
Fatal
can't help you, although some other modules might.
See the SEE ALSO section of this documentation.
You've found a bug in Fatal
. Please report it using
the perlbug
command.
Fatal
clobbers the context in which a function is called and always
makes it a scalar context, except when the :void
tag is used.
This problem does not exist in autodie.
"Used only once" warnings can be generated when autodie
or Fatal
is used with package filehandles (eg, FILE
). It's strongly recommended
you use scalar filehandles instead.
Original module by Lionel Cons (CERN).
Prototype updates by Ilya Zakharevich <ilya@math.ohio-state.edu>.
autodie support, bugfixes, extended diagnostics, system
support, and major overhauling by Paul Fenwick <pjf@perltraining.com.au>
This module is free software, you may distribute it under the same terms as Perl itself.
autodie for a nicer way to use lexical Fatal.
IPC::System::Simple for a similar idea for calls to system()
and backticks.