xref: /netbsd-src/lib/libc/stdio/fgetwc.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /* $NetBSD: fgetwc.c,v 1.4 2005/06/12 05:21:27 lukem 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 1.4 2005/06/12 05:21:27 lukem 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 
43 wint_t
44 __fgetwc_unlock(FILE *fp)
45 {
46 	struct wchar_io_data *wcio;
47 	mbstate_t *st;
48 	wchar_t wc;
49 	size_t size;
50 
51 	_DIAGASSERT(fp != NULL);
52 
53 	_SET_ORIENTATION(fp, 1);
54 	wcio = WCIO_GET(fp);
55 	if (wcio == 0) {
56 		errno = ENOMEM;
57 		return WEOF;
58 	}
59 
60 	/* if there're ungetwc'ed wchars, use them */
61 	if (wcio->wcio_ungetwc_inbuf) {
62 		wc = wcio->wcio_ungetwc_buf[--wcio->wcio_ungetwc_inbuf];
63 
64 		return wc;
65 	}
66 
67 	st = &wcio->wcio_mbstate_in;
68 
69 	do {
70 		char c;
71 		int ch = __sgetc(fp);
72 
73 		if (ch == EOF) {
74 			return WEOF;
75 		}
76 
77 		c = ch;
78 		size = mbrtowc(&wc, &c, 1, st);
79 		if (size == (size_t)-1) {
80 			errno = EILSEQ;
81 			return WEOF;
82 		}
83 	} while (size == (size_t)-2);
84 
85 	_DIAGASSERT(size == 1);
86 
87 	return wc;
88 }
89 
90 wint_t
91 fgetwc(FILE *fp)
92 {
93 	wint_t r;
94 
95 	_DIAGASSERT(fp != NULL);
96 
97 	FLOCKFILE(fp);
98 	r = __fgetwc_unlock(fp);
99 	FUNLOCKFILE(fp);
100 
101 	return (r);
102 }
103 
104