print STDOUT $string if $yeah;
        print $string;

# into
        print STDOUT $string if $yeah;
        print $string, "|$.|";
# $. is the current line input number, see perlvar for more


# and got

bash-2.05$ perl test.org.pl ./data/ out
|2||3||4|<s> so <s> so |5|we |6|can |7|do |8|it |9|again |10|yeah |11|yeah </s>
|12||13|bash-2.05$
bash-2.05$