Thanks again Alexander. The uploaded file contains genealogy data in the Gedcom format (plain text). The first processing phase generates a list of people and presents it to the requester as a table - one row per person. At the end of each row is a button which, if clicked, will do the second processing phase for that person. Running phase 2 for every person generated in phase 1 would take a long time and be wasteful - I would expect users to want to do phase 2 for only a few people (possibly zero).

Javascript is unable to extract the full path name from the form data - that's what I meant by "does not work".

Thanks for the tip about private tempfiles. I'll also look into sessions, which I've not used before.

Regards, J.