I’m trying to write a test case for some code that should iterates over a filesystem tree, but should stop if a file is on another device. In writing tests for it, I considered creating a file in /dev/shm, symlinking to it from my test directory, and then checking that it isn’t read, but /dev/shm seems to be Linux-specific. mount-ing a tmpfs could be an option, but it requires root…

Any ideas how this can be accomplished?