Hal Daume writes:
In GHC in the Posix module, there's GetProcessID:
Thanks for the pointer!
Unfortunately, this is a GHC-only solution, which is really annoying in my case because the software is completely compiler-independent, and I don't want to restrict it to GHC because I need it to determine a unique file name for a temporary file!
Is there no other way? I cannot be the first person ever to need a temporary file, can I? Surely there must be some portable way, too?
Even using a ProcessID doesn't guarnatee uniqueness, it just gives you a good chance that your file won't conflict - you still have to cope with the situation that a file with that name already exists. The right way to do this is to try to open it for writing, and try a different name if the open fails. Using System.Random to get a starting point is probably just as good as using the ProcessID, and is more portable. Cheers, Simon