| 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) %G% |
| 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 | } |