Linux IPC - Shared memory

 1. Create shared memory

 

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

 

if ((shm_id = shmget (mykey, sizeof (struct sharedbuf), 0600 | IFLAGS)) < 0)

    perror ("shmget");

2. Attach shared memory

 

char *buf = shmat (shm_id, 0, 0);

 

3. Read / Write shared memory

 

sharedbuf->size = size_;

 

memcpy(sharedbuf->buf, mybuf, size_);

 

memcpy(mybuf, sharedbuf->buf, sharedbuf->size);  

 

3. Detach shared memory (optional)

 

shmdt (buf);

 

4. Remove shared memory

 

if (shmctl (shm_id, IPC_RMID, (struct shmid_ds *)0) < 0) 

    perror ("shmctl");