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FTOK(3)		       FreeBSD Library Functions Manual		       FTOK(3)

NAME
     ftok -- create IPC	identifier from	path name

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <sys/types.h>
     #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.

SEE ALSO
     semget(2),	shmget(2), msgget(3)

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.

FreeBSD	9.3			 June 24, 1994			   FreeBSD 9.3

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO | HISTORY | AUTHORS | BUGS

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