in reply to Compare two txt files and print the difference between the two files.
If I'm understanding you correctly, you're interested in finding all items in the first file that are not in the second file. If this is the case, List::Compare can assist you with this:
use File::Slurp qw/read_file/;
chomp( my @a_file = read_file 'a_file.txt' );
chomp( my @b_file = read_file 'b_file.txt' );
my @a_file_only = List::Compare->new( \@a_file, \@b_file )->get_Lonly;
print "$_\n" for @a_file_only;
Output on your data sets:
Hope this helps!