I appreciate your detailed explanation, and hope the OP gets a chance to read your comments. As mentioned, my pedagogical intent was to (slowly) build upon the OP's code. Had I the need, I'd likely do the following:

my $last = '';
do { say if $_ ne $last; $last = $_ }
  for grep /\S/, <$fh>;

[download]

Thank you for the dialog on this issue...

In reply to Re^6: Delete Duplicate Entry in a text file by Kenosis
in thread Delete Duplicate Entry in a text file by astronogun

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