Provided by: libperl-critic-perl_1.148-1_all
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 v5.36.0 Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin(3pm)