Reference for unit 'ipc': Constants

`IPC_CREAT`		Create if key is nonexistent
`IPC_EXCL`		fail if key exists
`IPC_INFO`		For ipcs call
`IPC_NOWAIT`		return error on wait
`IPC_RMID`		Remove resource
`IPC_SET`		set ipc_perm options
`IPC_STAT`		get ipc_perm options
`MSGMAX`		Internal Message control code. Do not use
`MSGMNB`		Internal Message control code. Do not use
`MSGMNI`		Internal Message control code. Do not use
`MSG_EXCEPT`		Internal Message control code. Do not use
`MSG_NOERROR`		Internal Message control code. Do not use
`SEM_GETALL`		Semaphore operation: Get all semaphore values
`SEM_GETNCNT`		Semaphore operation: Get number of processes waiting for resource.
`SEM_GETPID`		Semaphore operation: Get process ID of last operation.
`SEM_GETVAL`		Semaphore operation: Get current value of semaphore
`SEM_GETZCNT`		Semaphore operation: Get number of processes waiting for semaphores to reach zero
`SEM_SEMMNI`		Semaphore operation: ?
`SEM_SEMMNS`		Semaphore operation: ?
`SEM_SEMMSL`		Semaphore operation: ?
`SEM_SEMOPM`		Semaphore operation: ?
`SEM_SEMVMX`		Semaphore operation: ?
`SEM_SETALL`		Semaphore operation: Set all semaphore values
`SEM_SETVAL`		Semaphore operation: Set semaphore value
`SEM_UNDO`		Constant for use in semop
`SHM_LOCK`		This constant is used in the shmctl call.
`SHM_R`		This constant is used in the shmctl call.
`SHM_RDONLY`		This constant is used in the shmctl call.
`SHM_REMAP`		This constant is used in the shmctl call.
`SHM_RND`		This constant is used in the shmctl call.
`SHM_UNLOCK`		This constant is used in the shmctl call.
`SHM_W`		This constant is used in the shmctl call.