Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin(3pm)
                                           User Contributed Perl Documentation


NAME
       Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin - Use "<>" or
       "<ARGV>" or a prompting module instead of "<STDIN>".

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

DESCRIPTION
       Perl has a useful magic filehandle called *ARGV that checks the command
       line and if there are any arguments, opens and reads those as files.
       If there are no arguments, *ARGV behaves like *STDIN instead.  This
       behavior is almost always what you want if you want to create a program
       that reads from "STDIN".  This is often written in one of the following
       two equivalent forms:

         while (<ARGV>) {
           # ... do something with each input line ...
         }
         # or, equivalently:
         while (<>) {
           # ... do something with each input line ...
         }

       If you want to prompt for user input, try special purpose modules like
       IO::Prompt.

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

CAVEATS
       Due to a bug in the current version of PPI (v1.119_03) and earlier, the
       readline operator is often misinterpreted as less-than and greater-than
       operators after a comma.  Therefore, this policy misses important cases
       like

         my $content = join '', <STDIN>;

       because it interprets that line as the nonsensical statement:

         my $content = join '', < STDIN >;

       When that PPI bug is fixed, this policy should start catching those
       violations automatically.

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

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

perl v5.38.0                      2023-07-26
                 Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin(3pm)