use warnings;
use strict;

my %h = (
          -r => sub { -r shift },
          -w => sub { -w shift },
);

my $testDir = '/tmp/';

checkDir( $testDir, '-w' );
checkDir( $testDir, '-r' );

sub checkDir {
  my ( $dir, $perm ) = @_;
  die '???' unless exists $h{$perm};
  if ( $h{$perm}($dir) ) {
    print "Can $perm $dir\n";
  }
  else {
    print "Can not $perm $dir\n";
  }
}