Perl::Critic::Policy::InputOutput::ProhibitExplicitStdinUser)Contributed Perl DocumenPerl::Critic::Policy::InputOutput::ProhibitExplicitStdin(3pm)
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 v5.14.2 2012-06-07 Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin(3pm)