This will work without library on data supplied.May fail on other data best to use jaffa's code if have File::Basename installed.

#!/usr/bin/perl 

use strict;
use warnings;


my %seen;
while (<DATA>) {
    m/^(.+\/)(.*)$/;
    my $path=$1;
    print "$path\n" unless $seen{$path}++;
}

__DATA__
testing123/
foobar/
helloworld/
helloworld/r1/
helloworld/r1/helloworld-5-0.noarch.rpm
helloworld/r1/testfile23.txt
helloworld/r1/tomcat-7.0.27.rpm
helloworld/r2/
helloworld/r2/helloworld-2-0.noarch.rpm
helloworld/r2/testfile12.txt
helloworld/r2/tomcat-5.0.52.rpm
hellotest/

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In reply to Re^2: Finding deepest directories in a tree structure represented in a flatfile? by grasshopper!!!
in thread Finding deepest directories in a tree structure represented in a flatfile? by Anonymous Monk

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