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Perl::Critic::Policy::InputOutput::RequireCheckedOpen - Write my $error = open $fh, $mode, $filename; instead of open $fh, $mode, $filename;.


This Policy is part of the core Perl::Critic distribution.


The perl builtin I/O function open returns a false value on failure. That value should always be checked to ensure that the open was successful.

    my $error = open( $filehandle, $mode, $filename );                  # ok
    open( $filehandle, $mode, $filename ) or die "unable to open: $!";  # ok
    open( $filehandle, $mode, $filename );                              # not ok

    use autodie;
    open $filehandle, $mode, $filename;                                 # ok

You can use autodie, Fatal, or Fatal::Exception to get around this. Currently, autodie is not properly treated as a pragma; its lexical effects aren't taken into account.


If you create a module that exports autodie you can tell this policy about it with the autodie_modules setting:

    autodie_modules = My::Thing


Andrew Moore <>


This policy module is based heavily on policies written by Jeffrey Ryan Thalhammer <>.


Copyright (c) 2007-2011 Andrew Moore. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license can be found in the LICENSE file included with this module.