IPC_CREAT   01000

Defines the input parameter used to create an IPC object.

IPC_EXCL   02000

Defines the input parameter used together with IPC_CREAT to prevent duplicate key values during IPC creation.

IPC_NOWAIT   04000

Defines the input parameter that specifies whether the communication is in non-blocking mode.

IPC_RMID   0

Defines the input parameter used to delete an IPC object.

IPC_SET   1

Defines the input parameter used to set information to the kernel.

IPC_INFO   3

Defines the input parameter used to obtain the system-level restriction information of a specified communication type, for example, shminfo.

IPC_PRIVATE   ((key_t) 0)

Defines the IPC object as a private object.