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 2005 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1986 AT&T	*/
28/*	  All Rights Reserved  	*/
29
30/*
31 * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
32 */
33
34/*	This module is created for NLS on Sep.03.86		*/
35
36/*
37 * Ungetwc saves the process code c into the one character buffer
38 * associated with an input stream "iop". That character, c,
39 * will be returned by the next getwc call on that stream.
40 */
41
42#include "lint.h"
43#include "file64.h"
44#include "mse_int.h"
45#include <stdio.h>
46#include <stdlib.h>
47#include <widec.h>
48#include <limits.h>
49#include <errno.h>
50#include "libc.h"
51#include "stdiom.h"
52#include "mse.h"
53
54static wint_t
55__ungetwc_impl(wint_t wc, FILE *iop, int orient)
56{
57	char		mbs[MB_LEN_MAX];
58	unsigned char	*p;
59	int		n;
60	rmutex_t	*lk;
61
62	FLOCKFILE(lk, iop);
63
64	if (orient && GET_NO_MODE(iop)) {
65		_setorientation(iop, _WC_MODE);
66	}
67	if ((wc == WEOF) || ((iop->_flag & _IOREAD) == 0)) {
68		FUNLOCKFILE(lk);
69		return (WEOF);
70	}
71
72	n = wctomb(mbs, (wchar_t)wc);
73	if (n <= 0) {
74		FUNLOCKFILE(lk);
75		return (WEOF);
76	}
77
78	if (iop->_ptr <= iop->_base) {
79		if (iop->_base == NULL) {
80			FUNLOCKFILE(lk);
81			return (WEOF);
82		}
83		if (iop->_ptr == iop->_base && iop->_cnt == 0) {
84			++iop->_ptr;
85		} else if ((iop->_ptr - n) < (iop->_base - PUSHBACK)) {
86			FUNLOCKFILE(lk);
87			return (WEOF);
88		}
89	}
90
91	p = (unsigned char *)(mbs + n - 1);
92	while (n--) {
93		*--(iop)->_ptr = (*p--);
94		++(iop)->_cnt;
95	}
96	iop->_flag &= ~_IOEOF;
97	FUNLOCKFILE(lk);
98	return (wc);
99}
100
101
102wint_t
103__ungetwc_xpg5(wint_t wc, FILE *iop)
104{
105	return (__ungetwc_impl(wc, iop, 1));
106}
107
108wint_t
109ungetwc(wint_t wc, FILE *iop)
110{
111	return (__ungetwc_impl(wc, iop, 0));
112}
113