1/* $NetBSD: fgetwc.c,v 1.12 2012/03/13 21:13:46 christos Exp $ */
2
3/*-
4 * Copyright (c)2001 Citrus Project,
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $Citrus$
29 */
30
31#include <sys/cdefs.h>
32#if defined(LIBC_SCCS) && !defined(lint)
33__RCSID("$NetBSD: fgetwc.c,v 1.12 2012/03/13 21:13:46 christos Exp $");
34#endif /* LIBC_SCCS and not lint */
35
36#include <assert.h>
37#include <errno.h>
38#include <stdio.h>
39#include <wchar.h>
40#include "reentrant.h"
41#include "local.h"
42
43wint_t
44__fgetwc_unlock(FILE *fp)
45{
46	struct wchar_io_data *wcio;
47	wchar_t wc;
48	size_t nr;
49
50	_DIAGASSERT(fp != NULL);
51
52	_SET_ORIENTATION(fp, 1);
53	wcio = WCIO_GET(fp);
54	_DIAGASSERT(wcio != NULL);
55
56	/* if there're ungetwc'ed wchars, use them */
57	if (wcio->wcio_ungetwc_inbuf)
58		return wcio->wcio_ungetwc_buf[--wcio->wcio_ungetwc_inbuf];
59
60	if (fp->_r <= 0) {
61restart:
62		if (__srefill(fp) != 0)
63			return WEOF;
64	}
65	nr = mbrtowc(&wc, (const char *)fp->_p,
66	    (size_t)fp->_r, &wcio->wcio_mbstate_in);
67	if (nr == (size_t)-1) {
68		fp->_flags |= __SERR;
69		return WEOF;
70	} else if (nr == (size_t)-2) {
71		fp->_p += fp->_r;
72		fp->_r = 0;
73		goto restart;
74	}
75	if (wc == L'\0') {
76		while (*fp->_p != '\0') {
77			++fp->_p;
78			--fp->_r;
79		}
80		nr = 1;
81	}
82	fp->_p += nr;
83	_DIAGASSERT(__type_fit(int, fp->_r - nr));
84	fp->_r -= (int)nr;
85
86	return wc;
87}
88
89wint_t
90fgetwc(FILE *fp)
91{
92	wint_t r;
93
94	_DIAGASSERT(fp != NULL);
95
96	FLOCKFILE(fp);
97	r = __fgetwc_unlock(fp);
98	FUNLOCKFILE(fp);
99
100	return r;
101}
102
103