sys/ipc.h - interprocess communication access structure
The <sys/ipc.h> header is used by three mechanisms for 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 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 read/write permission
The uid_t, gid_t, mode_t and key_t types are defined as described in <sys/types.h>.
Definitions are given for the following constants:
- Create entry if key does not exist.
- Fail if key exists.
- Error if request must wait.
- Private key.
- Remove identifier.
- Set options.
- Get options.
The following is declared as a function and may also be defined as a macro. Function prototypes must be provided for use with an ISO C compiler.
key_t ftok(const char *, int);