SYS_IPC.H(7) Miscellaneous Information Manual SYS_IPC.H(7)

sys/ipc.h — XSI interprocess communication access structure


#include <sys/ipc.h>

The <sys/ipc.h> header is used by three mechanisms for XSI interprocess communication (IPC): messages, semaphores, and shared memory. All use a common structure type, ipc_perm, to pass information used in determining permission to perform an IPC operation.

The <sys/ipc.h> header shall define the ipc_perm structure, which shall include 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   Read/write permission.

The <sys/ipc.h> header shall define the , , , and types as described in <sys/types.h>.

The <sys/ipc.h> header shall define the following symbolic constants.

Mode bits:

Create entry if key does not exist.
Fail if key exists.
Error if request would need to wait.

Keys:

Private key.

Control commands:

Remove identifier.
Set options.
Get options.

The following shall be declared as a function and may also be defined as a macro. A function prototype shall be provided.

key_t  ftok(const char *, int);

None.

None.

None.

<sys/types.h>

XSH ftok(3)

First released in Issue 2. Derived from System V Release 2.0.

This reference page is clarified with respect to macros and symbolic constants.

The description of IPC_NOWAIT is updated to eliminate the use of "must".

June 14, 2024 posix.fail