xref: /netbsd-src/lib/libc/stdio/fgetwc.c (revision 001c68bd94f75ce9270b69227c4199fbf34ee396)
1 /* $NetBSD: fgetwc.c,v 1.3 2003/03/07 07:11:36 tshiozak 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 <assert.h>
32 #include <errno.h>
33 #include <stdio.h>
34 #include <wchar.h>
35 #include "reentrant.h"
36 #include "local.h"
37 
38 wint_t
39 __fgetwc_unlock(FILE *fp)
40 {
41 	struct wchar_io_data *wcio;
42 	mbstate_t *st;
43 	wchar_t wc;
44 	size_t size;
45 
46 	_DIAGASSERT(fp != NULL);
47 
48 	_SET_ORIENTATION(fp, 1);
49 	wcio = WCIO_GET(fp);
50 	if (wcio == 0) {
51 		errno = ENOMEM;
52 		return WEOF;
53 	}
54 
55 	/* if there're ungetwc'ed wchars, use them */
56 	if (wcio->wcio_ungetwc_inbuf) {
57 		wc = wcio->wcio_ungetwc_buf[--wcio->wcio_ungetwc_inbuf];
58 
59 		return wc;
60 	}
61 
62 	st = &wcio->wcio_mbstate_in;
63 
64 	do {
65 		char c;
66 		int ch = __sgetc(fp);
67 
68 		if (ch == EOF) {
69 			return WEOF;
70 		}
71 
72 		c = ch;
73 		size = mbrtowc(&wc, &c, 1, st);
74 		if (size == (size_t)-1) {
75 			errno = EILSEQ;
76 			return WEOF;
77 		}
78 	} while (size == (size_t)-2);
79 
80 	_DIAGASSERT(size == 1);
81 
82 	return wc;
83 }
84 
85 wint_t
86 fgetwc(FILE *fp)
87 {
88 	wint_t r;
89 
90 	_DIAGASSERT(fp != NULL);
91 
92 	FLOCKFILE(fp);
93 	r = __fgetwc_unlock(fp);
94 	FUNLOCKFILE(fp);
95 
96 	return (r);
97 }
98 
99