xref: /illumos-gate/usr/src/lib/libc/port/stdio/rewind.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 #include "lint.h"
33 #include "file64.h"
34 #include "mtlib.h"
35 #include <sys/types.h>
36 #include <stdio.h>
37 #include <unistd.h>
38 #include <synch.h>
39 #include <thread.h>
40 #include "stdiom.h"
41 #include "libc.h"
42 
43 
44 void
45 rewind(FILE *iop)
46 {
47 	rmutex_t *lk;
48 
49 	FLOCKFILE(lk, iop);
50 	_rewind_unlocked(iop);
51 	FUNLOCKFILE(lk);
52 }
53 
54 void
55 _rewind_unlocked(FILE *iop)
56 {
57 	(void) _fflush_u(iop);
58 	(void) lseek64(FILENO(iop), 0, SEEK_SET);
59 	iop->_cnt = 0;
60 	iop->_ptr = iop->_base;
61 	iop->_flag &= ~(_IOERR | _IOEOF);
62 	if (iop->_flag & _IORW)
63 		iop->_flag &= ~(_IOREAD | _IOWRT);
64 }
65