Well, if you are on a Unix system, make use of its toolkit. One of the tools is called sort and usually has options to "merge, do not sort" and "uniques only". On my system, you these options are enable with -mu, but check your manual page. Then, instead of opening your file with: 
    open my $fh => "file" or die $!;

[download]
open it with: 
    open my $fh => "sort -mu file |" or die $!;

[download]

No counter needed, no check, no keeping track of the previous. Ultimate code reuse.

Abigail

In reply to Re: At each change in... by Abigail-II
in thread At each change in... by malaga

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