1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 /*
31 * Seek for standard library. Coordinates with buffering.
32 */
33
34 #pragma weak _fseek = fseek
35
36 #include "lint.h"
37 #include "file64.h"
38 #include "mtlib.h"
39 #include <stdio.h>
40 #include <errno.h>
41 #include <thread.h>
42 #include <synch.h>
43 #include <unistd.h>
44 #include <sys/types.h>
45 #include "stdiom.h"
46
47 int
fseek(FILE * iop,long offset,int ptrname)48 fseek(FILE *iop, long offset, int ptrname)
49 {
50 off_t p;
51 rmutex_t *lk;
52
53 FLOCKFILE(lk, iop);
54 iop->_flag &= ~_IOEOF;
55
56 if (!(iop->_flag & _IOREAD) && !(iop->_flag & (_IOWRT | _IORW))) {
57 errno = EBADF;
58 FUNLOCKFILE(lk);
59 return (-1);
60 }
61
62 if (iop->_flag & _IOREAD) {
63 if (ptrname == 1 && iop->_base && !(iop->_flag&_IONBF)) {
64 offset -= iop->_cnt;
65 }
66 } else if (iop->_flag & (_IOWRT | _IORW)) {
67 if (_fflush_u(iop) == EOF) {
68 FUNLOCKFILE(lk);
69 return (-1);
70 }
71 }
72 iop->_cnt = 0;
73 iop->_ptr = iop->_base;
74 if (iop->_flag & _IORW) {
75 iop->_flag &= ~(_IOREAD | _IOWRT);
76 }
77 p = _xseek(iop, (off_t)offset, ptrname);
78 FUNLOCKFILE(lk);
79 return ((p == (off_t)-1) ? -1: 0);
80 }
81