use strict;
use warnings;
use Data::Dumper;

my @strs =
  (
  '/Workstation_X_X/<someotherpath>/filename.xxx',
  '/Workstation_X_X/<someotherpath>/filename.xxx',
  '/Workstation_X_X/<someotherpath>/filename.yyy'
  );
  
my %unique;
@unique {@strs} = ();

print Dumper (\%unique);

##</code><code>##

$VAR1 = {
          '/Workstation_X_X/<someotherpath>/filename.xxx' => undef,
          '/Workstation_X_X/<someotherpath>/filename.yyy' => undef
        };