If mmap maps a file or device into memory, how do I do the reverse? I have some already-allocated memory, and I want to create a file descriptor from it that I can pass around. (shm_open doesn't do this, because I already have allocated memory.) Apparently Windows can do this: you can create a handle from some arbitrary region of user-allocated memory. Can Linux? Thanks, Dave -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/