Sachu,

Why do you want to store this state information in a single file? I think the solutions get a lot easier if you look at a broader array of structures.

First of all in order to do what you are saying you need to use the seek function to move to a particular place in a file. Secondly you would need to make sure that each record (i.e. test status pair) had a fixed length so that you could navigate easily through the file. You would - as you guess - need to deal with the issues of file locking. File locking is operating system specific and that is always best avoided.

I can see at least three better options:

• Use a database. You would need a simple table with two columns "test" and "status". I recomend the DBI module for handling databases.
• Instead of using a single file, use a single directory. Each record would be represented by a single file. I don't like this option - it looks like a lot of work.
• You could use the DB_File module to create a simple file based database. This makes some effort at solving the locking problem, but by its own admission it is flawed. It would at least work and be fairly easy and not depend on getting your hands on a database.