


Fatal(3p)        Perl Programmers Reference Guide       Fatal(3p)


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



perl v5.10.1                2009-10-12                          1





Fatal(3p)        Perl Programmers Reference Guide       Fatal(3p)


           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



perl v5.10.1                2009-10-12                          2





Fatal(3p)        Perl Programmers Reference Guide       Fatal(3p)


       <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.














































perl v5.10.1                2009-10-12                          3


