Why handle only one very specific relative path? Fix:

use strict;
use warnings;

use File::Basename        qw( fileparse );
use File::Spec::Functions qw( rel2abs );

my $file_path = './hello.world';

my ($file_name, $dir_path) = fileparse(rel2abs($file_path));

print("dir path:  $dir_path\n");
print("file name: $file_name\n");
[download]