- shared memory facility
The <sys/shm.h> header defines the following symbolic constants:
attach read-only (else read-write)
round attach address to SHMLBA
The <sys/shm.h> header defines the following symbolic value:
segment low boundary address multiple
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 shmid_ds structure 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>. See types.h(3HEAD).
In addition, all of the symbols from <sys/ipc.h> are defined when this header is included.
See attributes(5) for descriptions of the following attributes: