NAME¶
Perl::Critic::Policy::InputOutput::ProhibitTwoArgOpen - Write "open $fh,
q{<}, $filename;" instead of "open $fh,
"<$filename";".
AFFILIATION¶
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION¶
The three-argument form of "open" (introduced in Perl 5.6) prevents
subtle bugs that occur when the filename starts with funny characters like
'>' or '<'. The IO::File module provides a nice object-oriented
interface to filehandles, which I think is more elegant anyway.
open( $fh, '>output.txt' ); # not ok
open( $fh, q{>}, 'output.txt' ); # ok
use IO::File;
my $fh = IO::File->new( 'output.txt', q{>} ); # even better!
It's also more explicitly clear to define the input mode of the file, as in the
difference between these two:
open( $fh, 'foo.txt' ); # BAD: Reader must think what default mode is
open( $fh, '<', 'foo.txt' ); # GOOD: Reader can see open mode
This policy will not complain if the file explicitly states that it is
compatible with a version of perl prior to 5.6 via an include statement, e.g.
by having "require 5.005" in it.
CONFIGURATION¶
This Policy is not configurable except for the standard options.
NOTES¶
There are two cases in which you are forced to use the two-argument form of
open. When re-opening STDIN, STDOUT, or STDERR, and when doing a safe pipe
open, as described in perlipc.
SEE ALSO¶
IO::Handle
IO::File
AUTHOR¶
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>
COPYRIGHT¶
Copyright (c) 2005-2011 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.