fgetwc.c revision 103523 
1/*-
2 * Copyright (c) 2002 Tim J. Robbins.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/lib/libc/stdio/fgetwc.c 103523 2002-09-18 05:58:11Z tjr $");
29
30#include "namespace.h"
31#include <errno.h>
32#include <stdio.h>
33#include <stdlib.h>
34#include <wchar.h>
35#include "un-namespace.h"
36#include "libc_private.h"
37#include "local.h"
38
39wint_t
40fgetwc(FILE *fp)
41{
42	char buf[MB_LEN_MAX];
43	mbstate_t mbs;
44	size_t n, nconv;
45	int c;
46	wchar_t wc;
47
48	ORIENTLOCK(fp, 1);
49
50	n = 0;
51	while (n < MB_CUR_MAX) {
52		if ((c = fgetc(fp)) == EOF) {
53			if (n == 0)
54				return (WEOF);
55			break;
56		}
57		buf[n++] = (char)c;
58		memset(&mbs, 0, sizeof(mbs));
59		nconv = mbrtowc(&wc, buf, n, &mbs);
60		if (nconv == n)
61			return (wc);
62		else if (nconv == 0)
63			return (L'\0');
64		else if (nconv == (size_t)-2 || nconv == (size_t)-1)
65			break;
66	}
67
68	while (n-- != 0)
69		ungetc((unsigned char)buf[n], fp);
70	errno = EILSEQ;
71	return (WEOF);
72}
73