[BigETI]

It's bad practice to store files, which should be indexed, like this. We don't know how many files do exist, so you can basicly create a loop going to 2^31, and make yourself coffee (and wait hours or days), while your script still searches for the highest "indexed file" in your directory.

You can use databases, which are just the best option to use for such purposes. Alternatively you can create a table of file names, where you can keep track of all the files inside this directory.