| 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_PRIVATE |  | 
| 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. |