xref: /illumos-gate/usr/src/lib/libc/port/stdio/fseeko.c (revision 03831d35)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 /*
34  * Seek for standard library.  Coordinates with buffering.
35  */
36 
37 #include <sys/feature_tests.h>
38 
39 #if !defined(_LP64)
40 #pragma weak fseeko64 = _fseeko64
41 #endif
42 #pragma weak fseeko = _fseeko
43 
44 #include "synonyms.h"
45 #include "file64.h"
46 #include "mtlib.h"
47 #include <sys/types.h>
48 #include <unistd.h>
49 #include <limits.h>
50 #include <stdio.h>
51 #include <errno.h>
52 #include <thread.h>
53 #include <synch.h>
54 #include "stdiom.h"
55 
56 #if !defined(_LP64)
57 int
58 fseeko64(FILE *iop, off64_t offset, int ptrname)
59 {
60 	off64_t	p;
61 	rmutex_t *lk;
62 
63 	FLOCKFILE(lk, iop);
64 	iop->_flag &= ~_IOEOF;
65 
66 	if (!(iop->_flag & _IOREAD) && !(iop->_flag & (_IOWRT | _IORW))) {
67 		errno = EBADF;
68 		FUNLOCKFILE(lk);
69 		return (-1);
70 	}
71 
72 	if (iop->_flag & _IOREAD) {
73 		if (ptrname == 1 && iop->_base && !(iop->_flag&_IONBF)) {
74 			offset -= iop->_cnt;
75 		}
76 	} else if (iop->_flag & (_IOWRT | _IORW)) {
77 		if (_fflush_u(iop) == EOF) {
78 			FUNLOCKFILE(lk);
79 			return (-1);
80 		}
81 	}
82 	iop->_cnt = 0;
83 	iop->_ptr = iop->_base;
84 	if (iop->_flag & _IORW) {
85 		iop->_flag &= ~(_IOREAD | _IOWRT);
86 	}
87 	p = lseek64(FILENO(iop), offset, ptrname);
88 	FUNLOCKFILE(lk);
89 	return ((p == -1)? -1: 0);
90 }
91 #endif	/* _LP64 */
92 
93 int
94 fseeko(FILE *iop, off_t offset, int ptrname)
95 {
96 	return (fseek(iop, offset, ptrname));
97 }
98