Describes the structures that are used by the subroutines that perform interprocess communications operations.
#include <sys/ipc.h>
The ipc.h file defines the following symbolic constants, types, and structures:
IPC_CREAT create entry if key doesn't exist
IPC_EXCL fail if key exists
IPC_NOWAIT error if request must wait
IPC_PRIVATE private key
IPC_RMID remove identifier
IPC_SET set options
IPC_STAT get options
IPC_ALLO Centry currently allocated
IPC_R read or receive permission
IPC_W write or send permission
IPC_NOERROR truncates a message if too long
SHM_SIZE change segment size (shared mem only)
The structure ipc_perm contains the following members:
uid_t uid owner's user id
gid_t gid owner's group id
uid_t cuid creator's user id
gid_t cgid creator's group id
mode_t mode access modes
unsigned short seq slot usage sequence number
key_t key key
The types uid_t, gid_t, mode_t, and key_t are as defined in <sys/types.h>.
The following is declared as a function:
key_t ftok(const char *, int);