xref: /illumos-gate/usr/src/lib/libc/port/stdio/fseeko.c (revision 508a0e8cf1600b06c1f7361ad76e736710d3fdf8)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * Seek for standard library.  Coordinates with buffering.
34  */
35 
36 #include <sys/feature_tests.h>
37 
38 #if !defined(_LP64)
39 #pragma weak _fseeko64 = fseeko64
40 #endif
41 #pragma weak _fseeko = fseeko
42 
43 #include "lint.h"
44 #include "file64.h"
45 #include "mtlib.h"
46 #include <sys/types.h>
47 #include <unistd.h>
48 #include <limits.h>
49 #include <stdio.h>
50 #include <errno.h>
51 #include <thread.h>
52 #include <synch.h>
53 #include "stdiom.h"
54 
55 #if !defined(_LP64)
56 int
57 fseeko64(FILE *iop, off64_t offset, int ptrname)
58 {
59 	off64_t	p;
60 	rmutex_t *lk;
61 
62 	FLOCKFILE(lk, iop);
63 	iop->_flag &= ~_IOEOF;
64 
65 	if (!(iop->_flag & _IOREAD) && !(iop->_flag & (_IOWRT | _IORW))) {
66 		errno = EBADF;
67 		FUNLOCKFILE(lk);
68 		return (-1);
69 	}
70 
71 	if (iop->_flag & _IOREAD) {
72 		if (ptrname == 1 && iop->_base && !(iop->_flag&_IONBF)) {
73 			offset -= iop->_cnt;
74 		}
75 	} else if (iop->_flag & (_IOWRT | _IORW)) {
76 		if (_fflush_u(iop) == EOF) {
77 			FUNLOCKFILE(lk);
78 			return (-1);
79 		}
80 	}
81 	iop->_cnt = 0;
82 	iop->_ptr = iop->_base;
83 	if (iop->_flag & _IORW) {
84 		iop->_flag &= ~(_IOREAD | _IOWRT);
85 	}
86 	p = lseek64(FILENO(iop), offset, ptrname);
87 	FUNLOCKFILE(lk);
88 	return ((p == -1)? -1: 0);
89 }
90 #endif	/* _LP64 */
91 
92 int
93 fseeko(FILE *iop, off_t offset, int ptrname)
94 {
95 	return (fseek(iop, offset, ptrname));
96 }
97