Perl::Critic::Policy::Compatibility::ProhibitUnixDevNull - don't use explicit /dev/null
This policy is part of the Perl::Critic::Pulp addon. It ask you to not to use filename /dev/null explicitly, but instead File::Spec->devnull for maximum portability across operating systems.
Perl::Critic::Pulp
File::Spec->devnull
This policy is under the maintenance theme (see "POLICY THEMES" in Perl::Critic) on the basis that even if you're on a Unix system now you never know where your code might travel in the future.
maintenance
devnull is new in File::Spec version 0.8, so you should require that version (it's included in Perl 5.6.0 and up).
devnull
File::Spec
The checks for /dev/null are unsophisticated. A violation is reported for any string /dev/null, possibly with an open style mode part, or a qw containing /dev/null.
/dev/null
open
qw
open my $fh, '< /dev/null'; # bad do_something ("/dev/null"); # bad foreach my $file (qw(/dev/null /etc/passwd)) # bad
String comparisons are allowed because they're not uses of /dev/null as such but likely some sort of cross-platform check.
if ($f eq '/dev/null') { ... } # ok return ($f ne '>/dev/null'); # ok
"/dev/null" as just part of a string is allowed, including things like backticks and system.
system
print "Flames to /dev/null please\n" # ok system ('rmdir /foo/bar >/dev/null 2>&1'); # ok $hi = `echo hi </dev/null`; # ok
Whether /dev/null is a good idea in such command strings depends what sort of shell you reach and how much of Unix it might emulate on a non-Unix system.
If you only ever use a system with /dev/null, or if everything else you write is hopelessly wedded to Unix anyway, then you can disable ProhibitUnixDevNull from your .perlcriticrc in the usual way (see "CONFIGURATION" in Perl::Critic),
ProhibitUnixDevNull
[-Compatibility::ProhibitUnixDevNull]
Perl::Critic::Pulp, Perl::Critic, File::Spec
http://user42.tuxfamily.org/perl-critic-pulp/index.html
Copyright 2009, 2010, 2011 Kevin Ryde
Perl-Critic-Pulp is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.
Perl-Critic-Pulp is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with Perl-Critic-Pulp. If not, see <http://www.gnu.org/licenses/>.
To install Perl::Critic::Pulp, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Perl::Critic::Pulp
CPAN shell
perl -MCPAN -e shell install Perl::Critic::Pulp
For more information on module installation, please visit the detailed CPAN module installation guide.