1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * %sccs.include.redist.c% 9 * 10 * @(#)lseek.c 8.1 (Berkeley) 06/11/93 11 * 12 * 13 * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University 14 * All Rights Reserved. 15 * 16 * Author: Alessandro Forin 17 * 18 * Permission to use, copy, modify and distribute this software and its 19 * documentation is hereby granted, provided that both the copyright 20 * notice and this permission notice appear in all copies of the 21 * software, derivative works or modified versions, and any portions 22 * thereof, and that both notices appear in supporting documentation. 23 * 24 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 25 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 26 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 27 * 28 * Carnegie Mellon requests users of this software to return to 29 * 30 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 31 * School of Computer Science 32 * Carnegie Mellon University 33 * Pittsburgh PA 15213-3890 34 * 35 * any improvements or extensions that they make and grant Carnegie the 36 * rights to redistribute these changes. 37 */ 38 39 #include <stand/stand.h> 40 41 off_t 42 lseek(fd, offset, where) 43 int fd; 44 off_t offset; 45 int where; 46 { 47 register struct open_file *f = &files[fd]; 48 49 if ((unsigned)fd >= SOPEN_MAX || f->f_flags == 0) { 50 errno = EBADF; 51 return (-1); 52 } 53 54 /* seek is not supported on raw devices */ 55 if (f->f_flags & F_RAW) 56 return ((off_t)-1); 57 58 return (f->f_ops->seek)(f, offset, where); 59 } 60