Great! Finally I'm understanding what's behind the split function!

When you enclose the expression with parenthesis, the string is splitted according to the pattern but the matched separators are also stored in the resulting array. That's really interesting, because you can easily manipulate in the same array both, the separated stuff and the separators. See my example below:

#! /usr/bin/perl
use Data::Dumper;

$re = "(ab+)";
$input = "uno abb dos ab tres abbb cuatro";
my @splits = split /$re/, $input;
print "splits: ", Dumper \@splits;

__END__

splits: $VAR1 = [
          'uno ',
          'abb',
          ' dos ',
          'ab',
          ' tres ',
          'abbb',
          ' cuatro'
        ];
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