#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;
use feature 'say';
use Test::More;

my $file = $ARGV[0];
my @sb = stat( $file );
my $mode = $sb[2] & 0777;

warn "mode of [$file] is [$mode]";

ok( -O $file, "File owned by real uid" );
ok( -f $file, "File is a plain file" );
ok( ! ( $mode & 022 ), "File is not group or world writable" );

done_testing;

 $ perlcritic ./foo.pl 
Integer with leading zeros: "0777" at line 11, column 21.  See page 58 of PBP.  (Severity: 5)
Integer with leading zeros: "022" at line 17, column 17.  See page 58 of PBP.  (Severity: 5)