Your description leaves too much room for interpretation.

I assume you just want to "collapse" consecutive lines and you don't care about "repetitions" which are separated.

Hence no %seen hash is needed, just remember the $last line aka array and compare it to the $current one.

If the $current one fits your criteria add it to $last, if it doesn't print $last and make $last=$current for the next iteration.

Cheers Rolf
(addicted to the Perl Programming Language :)
see Wikisyntax for the Monastery

In reply to Re: Summing up duplicate lines by LanX
in thread Summing up duplicate lines by oko1

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