Provided by: perl-doc_5.26.1-6_all bug

NAME

       Fatal - Replace functions with equivalents which succeed or die

SYNOPSIS

           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');

BEST PRACTICE

       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.

DESCRIPTION

       "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.

DIAGNOSTICS

       Bad subroutine name for Fatal: %s
           You've called "Fatal" with an argument that doesn't look like a subroutine name, nor a
           switch that this version of Fatal understands.

       %s is not a Perl subroutine
           You've asked "Fatal" to try and replace a subroutine which does not exist, or has not
           yet been defined.

       %s is neither a builtin, nor a Perl subroutine
           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.

       Cannot make the non-overridable %s fatal
           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.

       Internal error: %s
           You've found a bug in "Fatal".  Please report it using the "perlbug" command.

BUGS

       "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.

AUTHOR

       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>

LICENSE

       This module is free software, you may distribute it under the same terms as Perl itself.

SEE ALSO

       autodie for a nicer way to use lexical Fatal.

       IPC::System::Simple for a similar idea for calls to "system()" and backticks.