Perl::Critic::Policy::InputOutput::RequireCheckedSyscalls(3pm)

NAME
Perl::Critic::Policy::InputOutput::RequireCheckedSyscalls - Return value of flagged function ignored.

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

DESCRIPTION
This performs identically to InputOutput::RequireCheckedOpen/Close except that this is configurable to apply to any function, whether core or user-defined.

If your module uses Fatal, Fatal::Exception, or autodie then any functions wrapped by those modules will not trigger this policy. For example:

    use Fatal qw(open);
    open my $fh, $filename;  # no violation
    close $fh;               # yes violation

    use autodie;
    open $filehandle, $mode, $filename;   # no violation

Currently, autodie is not properly treated as a pragma; its lexical effects aren't taken into account.

CONFIGURATION
This policy watches for a configurable list of function names. By default, it applies to "open", "print", "say" and "close". You can override this to set it to a different list of functions with the "functions" and "exclude_functions" settings. To do this, put entries in a .perlcriticrc file like this:

    [InputOutput::RequireCheckedSyscalls]
    functions = open opendir read readline readdir close closedir

We have defined a few shortcuts for creating this list

    [InputOutput::RequireCheckedSyscalls]
    functions = :defaults opendir readdir closedir

    [InputOutput::RequireCheckedSyscalls]
    functions = :builtins

    [InputOutput::RequireCheckedSyscalls]
    functions = :all

The ":builtins" shortcut above represents all of the builtin functions that have error conditions (about 65 of them, many of them rather obscure).

You can require checking all builtins except "print" by combining the "functions" and "exclude_functions":

    [InputOutput::RequireCheckedSyscalls]
    functions = :builtins
    exclude_functions = print

This is a lot easier to read than the alternative.

The ":all" is the insane case: you must check the return value of EVERY function call, even "return" and "exit". Yes, this "feature" is overkill and is wasting CPU cycles on your computer by just existing. Nyah nyah. I shouldn't code after midnight.

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

    [InputOutput::RequireCheckedSyscalls]
    autodie_modules = My::Thing

CREDITS
Initial development of this policy was supported by a grant from the Perl Foundation.

This policy module is based heavily on policies written by Andrew Moore <amoore@mooresystems.com>.

AUTHOR
Chris Dolan <cdolan@cpan.org>

COPYRIGHT
Copyright (c) 2007-2011 Chris Dolan. Many 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.