1 /* $NetBSD: ftok.c,v 1.9 2000/01/22 22:19:10 mycroft 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 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 #if defined(LIBC_SCCS) && !defined(lint) 32 __RCSID("$NetBSD: ftok.c,v 1.9 2000/01/22 22:19:10 mycroft Exp $"); 33 #endif /* LIBC_SCCS and not lint */ 34 35 #include "namespace.h" 36 #include <sys/types.h> 37 #include <sys/stat.h> 38 #include <sys/ipc.h> 39 40 #include <assert.h> 41 #include <errno.h> 42 43 #ifdef __weak_alias 44 __weak_alias(ftok,_ftok) 45 #endif 46 47 key_t 48 ftok(path, id) 49 const char *path; 50 int id; 51 { 52 struct stat st; 53 54 _DIAGASSERT(path != NULL); 55 56 if (stat(path, &st) < 0) 57 return (key_t)-1; 58 59 return (key_t) 60 (id << 24 | (st.st_dev & 0xff) << 16 | (st.st_ino & 0xffff)); 61 } 62