1 /* $NetBSD: lseek.c,v 1.6 2000/03/30 12:19:48 augustss Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)lseek.c 8.1 (Berkeley) 6/11/93 39 * 40 * 41 * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University 42 * All Rights Reserved. 43 * 44 * Author: Alessandro Forin 45 * 46 * Permission to use, copy, modify and distribute this software and its 47 * documentation is hereby granted, provided that both the copyright 48 * notice and this permission notice appear in all copies of the 49 * software, derivative works or modified versions, and any portions 50 * thereof, and that both notices appear in supporting documentation. 51 * 52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 54 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55 * 56 * Carnegie Mellon requests users of this software to return to 57 * 58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59 * School of Computer Science 60 * Carnegie Mellon University 61 * Pittsburgh PA 15213-3890 62 * 63 * any improvements or extensions that they make and grant Carnegie the 64 * rights to redistribute these changes. 65 */ 66 67 #include "stand.h" 68 69 off_t 70 #ifndef __INTERNAL_LIBSA_CREAD 71 lseek(fd, offset, where) 72 #else 73 olseek(fd, offset, where) 74 #endif 75 int fd; 76 off_t offset; 77 int where; 78 { 79 struct open_file *f = &files[fd]; 80 81 #if !defined(LIBSA_NO_FD_CHECKING) 82 if ((unsigned)fd >= SOPEN_MAX || f->f_flags == 0) { 83 errno = EBADF; 84 return (-1); 85 } 86 #endif 87 88 #if !defined(LIBSA_NO_RAW_ACCESS) 89 if (f->f_flags & F_RAW) { 90 /* 91 * On RAW devices, update internal offset. 92 */ 93 switch (where) { 94 case SEEK_SET: 95 f->f_offset = offset; 96 break; 97 case SEEK_CUR: 98 f->f_offset += offset; 99 break; 100 case SEEK_END: 101 default: 102 errno = EOFFSET; 103 return (-1); 104 } 105 return (f->f_offset); 106 } 107 #endif 108 109 return FS_SEEK(f->f_ops)(f, offset, where); 110 } 111