shmid_ds
#define NULL_SHM ((struct shmid_ds *)NULL)
struct shmid_ds stat;
struct shmid_ds shmid_ds;
memset(&shmid_ds, 0, sizeof(shmid_ds));
if ((r = shmctl(shmid, IPC_STAT, &shmid_ds)) < 0)
shmid_ds.shm_perm.uid = uid;
shmid_ds.shm_perm.gid = gid;
shmid_ds.shm_perm.mode = mode;
if ((r = shmctl(shmid, IPC_SET, &shmid_ds)) < 0)
struct shmid_ds shmds;
shmctl(int shmid, int cmd, struct shmid_ds *buf)
struct shmid_ds mds;
struct shmid_ds shm_buf;
STRUCT_DECL(shmid_ds, ds); /* for SVR4 IPC_SET */
int shmctl(int, int, struct shmid_ds *);