NAME

       Perl::Critic::Policy::Compatibility::ProhibitUnixDevNull - don't use explicit /dev/null

DESCRIPTION

       This policy is part of the "Perl::Critic::Pulp" add-on.  It ask you to not to use filename

           /dev/null

       explicitly, but instead "File::Spec->devnull()" for maximum portability across operating
       systems.

       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.

       "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).

       The checks for /dev/null are unsophisticated.  A violation is reported for any string
       "/dev/null", possibly with an "open" style mode part, and any "qw" containing "/dev/null".

           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".

           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 with that command and how much of Unix it might emulate on a non-Unix system.

   Disabling
       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),

           [-Compatibility::ProhibitUnixDevNull]

SEE ALSO

       Perl::Critic::Pulp, Perl::Critic, File::Spec

HOME PAGE

       <http://user42.tuxfamily.org/perl-critic-pulp/index.html>

COPYRIGHT

       Copyright 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2019, 2021 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/>.

perl v5.32.1                        Perl::Critic::Policy::Compatibility::ProhibitUnixDevNull(3pm)