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FTOK(3) BSD Library Functions Manual FTOK(3) NAME ftok -- create IPC identifier from path name LIBRARY Standard C Library (libc, -lc) SYNOPSIS #include <sys/ipc.h> key_t ftok(const char *path, int id); DESCRIPTION The ftok() function attempts to create a unique key suitable for use with the msgget(3), 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. SEE ALSO semget(2), shmget(2), msgget(3), compat(5) HISTORY The ftok() function originates with System V and is typically used by programs that use the System V IPC routines. AUTHORS Thorsten Lockert <tholo@sigmasoft.com> BUGS The returned key is computed based on the device minor number and inode of the specified path, in combination with the lower 8 bits of the given id. Thus, it is quite possible for the routine to return duplicate keys. BSD June 24, 1994 BSD |