|FTOK(3)||Library Functions Manual||FTOK(3)|
char *path, int
ftok() function attempts to create a unique key suitable for use with the msgget(2), semget(2) and shmget(2) functions given the path of an existing file and a user-selectable id.
The specified path must refer to an existing file that is accessible to the calling process or the call will fail. Also, note that links to files will return the same key, given the same id. Only the 8 least significant bits of id are used in the key generation; the rest of the bits are ignored.
ftok() function will return (key_t)-1 if path does not exist or if it cannot be accessed by the calling process.
ftok() function originated with System V and is typically used by programs that use the System V IPC routines.
|November 15, 2014||OpenBSD-current|