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

NAME
Perl::Critic::Policy::InputOutput::ProhibitBarewordDirHandles - Write "opendir my $dh, $dirname;" instead of "opendir DH, $dirname;".

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

DESCRIPTION
Using bareword symbols to refer to directory handles is particularly evil because they are global, and you have no idea if that symbol already points to some other file or directory handle. You can mitigate some of that risk by "local"izing the symbol first, but that's pretty ugly. Since Perl 5.6, you can use an undefined scalar variable as a lexical reference to an anonymous file handle or directory handle. Alternatively, see the IO::Handle or IO::Dir modules for an object-oriented approach.

    opendir DH, $some_dir;            #not ok
    opendir *DH, $some_dir;           #not ok
    opendir \*DH, $some_dir;          #not ok
    opendir local *DH, $some_dir;     #not ok
    opendir $dh, $some_dir;           #ok
    opendir my $dh, $some_dir;        #ok
    opendir our $dh, $some_dir;       #ok
    opendir local $dh, $some_dir;     #ok
    my $dh = IO::Dir->new($some_dir); #ok

And Perl7 will probably drop support for bareword filehandles.

CONFIGURATION
This Policy is not configurable except for the standard options.

SEE ALSO
Perl::Critic::Policy::InputOutput::ProhibitBarewordFileHandles::Perl::Critic::Policy::InputOutput::ProhibitBarewordFileHandles

IO::Handle

IO::Dir

AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>, "github.com/pali", "github.com/raforg"

COPYRIGHT
Copyright (c) 2005-2011, 2021 Imaginative Software Systems. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.