sys/shm.h - shared memory facility
The <sys/shm.h> header defines the following symbolic constants and structure:
- Attach read-only (else read-write).
- Segment low boundary address multiple.
- Round attach address to SHMLBA.
The following data types are defined through typedef:
Unsigned integer used for the number of current attaches that must be able to store values at least as large as a type unsigned short.
The structure shmid_ds contains the following members:
struct ipc_perm shm_perm operation permission structure size_t shm_segsz size of segment in bytes pid_t shm_lpid process ID of last shared memory operation pid_t shm_cpid process ID of creator shmatt_t shm_nattch number of current attaches time_t shm_atime time of last shmat() time_t shm_dtime time of last shmdt() time_t shm_ctime time of last change by shmctl()
The pid_t, time_t, key_t and size_t types are defined as described in <sys/types.h>. The following are declared as functions and may also be defined as macros. Function prototypes must be provided for use with an ISO C compiler.
void *shmat(int, const void *, int); int shmctl(int, int, struct shmid_ds *); int shmdt(const void *); int shmget(key_t, size_t, int);
In addition, all of the symbols from <sys/ipc.h> will be defined when this header is included.
shmat(), shmctl(), shmdt(), shmget(), <sys/types.h>.