GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages
Fatal(3) User Contributed Perl Documentation Fatal(3)
 

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.

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.

"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.
2015-07-09 perl v5.28.1

Search for    or go to Top of page |  Section 3 |  Main Index

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with ManDoc.