1 /* $NetBSD: ftok.c,v 1.11 2012/03/20 16:36:05 matt Exp $ */ 2 3 /* 4 * Copyright (c) 1994 SigmaSoft, Th. Lockert <tholo@sigmasoft.com> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #if defined(LIBC_SCCS) && !defined(lint) 30 __RCSID("$NetBSD: ftok.c,v 1.11 2012/03/20 16:36:05 matt Exp $"); 31 #endif /* LIBC_SCCS and not lint */ 32 33 #include "namespace.h" 34 #include <sys/types.h> 35 #include <sys/stat.h> 36 #include <sys/ipc.h> 37 38 #include <assert.h> 39 #include <errno.h> 40 41 #ifdef __weak_alias 42 __weak_alias(ftok,_ftok) 43 #endif 44 45 key_t 46 ftok(const char *path, int id) 47 { 48 struct stat st; 49 50 _DIAGASSERT(path != NULL); 51 52 if (stat(path, &st) < 0) 53 return (key_t)-1; 54 55 return (key_t) 56 (id << 24 | (st.st_dev & 0xff) << 16 | (st.st_ino & 0xffff)); 57 } 58