NAME

Perl::Critic::Policy::InputOutput::ProhibitBarewordFileHandles - Write "open my $fh, q{<}, $filename;" instead of "open FH, q{<}, $filename;".

AFFILIATION

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

DESCRIPTION

Using bareword symbols to refer to file handles is particularly evil because they are global, and you have no idea if that symbol already points to some other file 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 filehandle. Alternatively, see the IO::Handle or IO::File or FileHandle modules for an object-oriented approach.

    open FH, '<', $some_file;           #not ok
    open my $fh, '<', $some_file;       #ok
    my $fh = IO::File->new($some_file); #ok

There are three exceptions: STDIN, STDOUT and STDERR. These three standard filehandles are always package variables.

This policy also applies to the "sysopen" function as well.

CONFIGURATION

This Policy is not configurable except for the standard options.

SEE ALSO

IO::Handle

IO::File

AUTHOR

Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT

Copyright (c) 2005-2022 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.