in reply to parsing a file

Have your parsing code call a function that does the processing once it finally has all the data for user N. When building your parsing code, have your processing function print out the Data::Dumper output of the input to the function.

You might want to look at the flip-flop operator within nested while-loops. Check out This code is just freaky...

Being right, does not endow the right to be rude; politeness costs nothing.
Being unknowing, is not the same as being stupid.
Expressing a contrary opinion, whether to the individual or the group, is more often a sign of deeper thought than of cantankerous belligerence.
Do not mistake your goals as the only goals; your opinion as the only opinion; your confidence as correctness. Saying you know better is not the same as explaining you know better.

In Section Seekers of Perl Wisdom