NAME
autodie - Replace functions with ones that succeed or die with lexical scope
SYNOPSIS
use autodie; # Recommended, implies 'use autodie qw(:all)'
use autodie qw(open close); # open/close succeed or die
open(my $fh, "<", $filename); # No need to check!
{
no autodie qw(open); # open failures won't die
open(my $fh, "<", $filename); # Could fail silently!
no autodie; # disable all autodies
}
DESCRIPTION
bIlujDI' yIchegh()Qo'; yIHegh()!
It is better to die() than to return() in failure.
-- Klingon programming proverb.
NOTE! This is BETA code. It is NOT the final release. Implementation and interface may change!
The autodie
pragma provides a convenient way to replace functions that normally return false on failure with equivalents that throw an exception on failure.
The autodie
pragma has lexical scope, meaning that functions and subroutines altered with autodie
will only change their behaviour until the end of the enclosing block, file, or eval
.
If system
is specified as an argument to autodie
, then it uses IPC::System::Simple to do the heavy lifting. See the description of that module for more information.
EXCEPTIONS
Exceptions produced by the autodie
pragma are members of the autodie::exception class. The preferred way to work with these exceptions is as follows:
use feature qw(switch);
eval {
use autodie ':io';
open(my $fh, '<', $some_file);
my @records = <$fh>;
close($fh);
};
given ($@) {
when (undef) { say "No error"; }
when ('open') { say "Error from open"; }
when (':io') { say "Non-open, IO error."; }
when (':all') { say "All other autodie errors." }
default { say "Not an autodie error at all." }
}
See autodie::exception for further information on interrogating exceptions.
GOTCHAS
Functions called in list context are assumed to have failed if they return an empty list, or a list consisting only of a single undef element.
BUGS
autodie
only works on Perl 5.10. We'd like it to be able to work on Perl 5.8.
Currently, autodying system
returns only a string, not a real exception object. This will change before the full release.
A bare autodie will change from meaning :all
to :default
before the final release.
AUTHOR
Copyright 2008, 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
Fatal, autodie::exception, IPC::System::Simple
ACKNOWLEDGEMENTS
Mark Reed and Roland Giersig -- Klingon translators.