POSIX Shared Memory

POSIX shared memory is actually a variation of mapped memory (see Creating and Using Mappings). The major differences are:

• You use shm_open(3RT) to open the shared memory object instead of calling open(2).

• You use shm_unlink(3RT) to close and delete the object instead of calling close(2) which does not remove the object.

The options in shm_open(3RT) are substantially fewer than the number of options provided in open(2).