I believe the CPAN palm module lets you create empty Palm::PDB objects (the super class of each specific type of database), populate them, and write them back out to disk. Take a look at perldoc Palm::PDB.

As a secondary point: You're post didn't specificly mention that you wanted to sync these databases with a handhelded, but assuming you do, keep in mind that just creating a .pdb is only half the battle. Unless your conduit understands what's going on, you could find yourself adding duplicate records, or blowing away data entered manually on the handheld.

"Syncing" happens in the conduits themselves, and each conduit decides how to handle merging, so instead of writting a script to generate a .pdb from some data, and then worrying about how your syncing conduit will deal with it, you might just wnat to write a conduit that imports the data directly.

If you're developing on Unix, your HotSyncing program is probably built on top of pilot-link -- the www site has lots of links with information on writting conduits.