# uniqfiles.pl
use strict; # helps prevent silly mistakes
use warnings; # helpful when writing code

while (<>) {  # Reads from STDIN
   if (/^(\w+)\t/) { # If the line starts with one or more 'word' characters followed by a tab...
      my $filename = $1; # ...assume we've got a filename captured
      $uniq_fnames{$filename} = 1; # ...and add it to our hash.
   }
}
print $_,"\n" for keys %uniq_fnames;  # prints to STDOUT, can be piped to a file

##</code><code>##

perl uniqfiles.pl < my_non_unique_list_of_files > my_unique_list_of_files