1 /* $OpenBSD: lseek.c,v 1.4 1997/02/06 02:56:45 downsj Exp $ */ 2 /* $NetBSD: lseek.c,v 1.3 1996/06/21 20:09:03 pk Exp $ */ 3 4 /*- 5 * Copyright (c) 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * The Mach Operating System project at Carnegie-Mellon University. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)lseek.c 8.1 (Berkeley) 6/11/93 40 * 41 * 42 * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University 43 * All Rights Reserved. 44 * 45 * Author: Alessandro Forin 46 * 47 * Permission to use, copy, modify and distribute this software and its 48 * documentation is hereby granted, provided that both the copyright 49 * notice and this permission notice appear in all copies of the 50 * software, derivative works or modified versions, and any portions 51 * thereof, and that both notices appear in supporting documentation. 52 * 53 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 54 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 55 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 56 * 57 * Carnegie Mellon requests users of this software to return to 58 * 59 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 60 * School of Computer Science 61 * Carnegie Mellon University 62 * Pittsburgh PA 15213-3890 63 * 64 * any improvements or extensions that they make and grant Carnegie the 65 * rights to redistribute these changes. 66 */ 67 68 #include "stand.h" 69 70 off_t 71 #ifndef __INTERNAL_LIBSA_CREAD 72 lseek(fd, offset, where) 73 #else 74 olseek(fd, offset, where) 75 #endif 76 int fd; 77 off_t offset; 78 int where; 79 { 80 register struct open_file *f = &files[fd]; 81 82 if ((unsigned)fd >= SOPEN_MAX || f->f_flags == 0) { 83 errno = EBADF; 84 return (-1); 85 } 86 87 if (f->f_flags & F_RAW) { 88 /* 89 * On RAW devices, update internal offset. 90 */ 91 switch (where) { 92 case SEEK_SET: 93 f->f_offset = offset; 94 break; 95 case SEEK_CUR: 96 f->f_offset += offset; 97 break; 98 case SEEK_END: 99 default: 100 errno = EOFFSET; 101 return (-1); 102 } 103 return (f->f_offset); 104 } 105 106 return (f->f_ops->seek)(f, offset, where); 107 } 108