48.2. Creating or Opening a Shared Memory Segment

The shmget() system call creates a new shared memory segment or obtains the identifier of an existing segment. The contents of a newly created shared memory segment are initialized to 0.

#include <sys/types.h>        /* For portability */
#include <sys/shm.h>

int shmget(key_t key, size_t size, int shmflg);