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perl::critic::policy::inputoutput::requireencodingwithutf8layer(3pm) [debian man page]

Perl::Critic::Policy::InputOutput::RequireEncodingWithUTUseryContributed Perl Perl::Critic::Policy::InputOutput::RequireEncodingWithUTF8Layer(3pm)

NAME

       Perl::Critic::Policy::InputOutput::RequireEncodingWithUTF8Layer - Write "open $fh, q{<:encoding(UTF-8)}, $filename;" instead of "open $fh,
       q{{<:utf8}, $filename;".

AFFILIATION

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

DESCRIPTION

       Use of the ":utf8" I/O layer (as opposed to ":encoding(UTF8)" or ":encoding(UTF-8)") was suggested in the Perl documentation up to version
       5.8.8. This may be OK for output, but on input ":utf8" does not validate the input, leading to unexpected results.

       An exploit based on this behavior of ":utf8" is exhibited on PerlMonks at <http://www.perlmonks.org/?node_id=644786>. The exploit involves
       a string read from an external file and sanitized with "m/^(w+)$/", where $1 nonetheless ends up containing shell meta-characters.

       To summarize:

	open $fh, '<:utf8', 'foo.txt';		   # BAD
	open $fh, '<:encoding(UTF8)', 'foo.txt';   # GOOD
	open $fh, '<:encoding(UTF-8)', 'foo.txt';  # BETTER

       See the Encode documentation for the difference between "UTF8" and "UTF-8". The short version is that "UTF-8" implements the Unicode
       standard, and "UTF8" is liberalized.

       For consistency's sake, this policy checks files opened for output as well as input, For complete coverage it also checks "binmode()"
       calls, where the direction the operation can not be determined.

CONFIGURATION

       This Policy is not configurable except for the standard options.

NOTES

       Because "Perl::Critic" does a static analysis, this policy can not detect cases like

	my $encoding = ':utf8';
	binmode $fh, $encoding;

       where the encoding is computed.

SEE ALSO

       PerlIO

       Encode

       "perldoc -f binmode"

       <http://www.socialtext.net/perl5/index.cgi?the_utf8_perlio_layer>

       <http://www.perlmonks.org/?node_id=644786>

AUTHOR

       Thomas R. Wyant, III wyant at cpan dot org

COPYRIGHT

       Copyright (c) 2010-2011 Thomas R. Wyant, III

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

perl v5.14.2							    2012-06-07Perl::Critic::Policy::InputOutput::RequireEncodingWithUTF8Layer(3pm)

Check Out this Related Man Page

Perl::Critic::Policy::InputOutput::ProhibitExplicitStdinUser Contributed Perl DocumentaPerl::Critic::Policy::InputOutput::ProhibitExplicitStdin(3)

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 v5.16.3							    2014-06-09	       Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin(3)
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