ftok3
Create ipc identifier from path name
Usage
#include <sys/ipc.h>
key_t
ftok(const char *path, int id);
Library
Standard C Library (libc, -lc)
Overview
The ftok() function attempts to create a unique key suitable for use with the semget(2), and shmget(2) functions given the path of an existing file and a user-selectable id.
The specified path must specify 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.
Return values
The ftok() function will return -1 if path does not exist or if it cannot be accessed by the calling process.
Legacy synopsis
#include <sys/types.h> #include <sys/ipc.h>
The include file ⟨sys/types.h⟩ is necessary.
Releases
164 releases since Mac OS X 10.0; the text changed 6 times.