Question

This question relates to Simulating file system access .

I need to choose files and directories randomly to act as arguments of file operations like rename, write, read etc. What I was planning to do was to make a list of all files and directories with thier paths and randomly select from this list. But, as files and directories are created and deleted in the actual file system, the list also has to be updated. I am finding maintaining the list and updating it in this manner to be inefficient and it also has to be atomic so that a later operation does not access a file that was deleted by a previous operation.

Can you suggest a different way of selecting the files ..maybe someway to do it diretly from the file system…but how would we know paths to files then.

Thanks

I found something interesting here Randomly selecting a file from a tree of directories in a completely fair manner specially in
Michael J. Barber’s answer, but not being able to follow it completely due to my python ignorance

Answer 1

You don’t want to try to maintain a list of files when the filesystem is right there. You should be able to do it right from C. Walk from the root directory, selecting a random file from it. You can pick a random maximum depth, and if you hit a regular file, at or before this, use it. If it’s a directory, repeat up to max depth. If it’s a special file, maybe start over.

This should be pretty quick. The operation shouldn’t have to be atomic. If the file’s not there when you want do your operation, try again. Shouldn’t be too complicated. You can build the path up as you find your target file. This will be simpler than fussing with the fs directly (I assume you meant at a much lower level) and should be simple to implement.