xref: /dragonfly/lib/libc/stdio/ungetwc.c (revision cfd1aba3)
1 /*-
2  * Copyright (c) 2002-2004 Tim J. Robbins.
3  * All rights reserved.
4  *
5  * Copyright (c) 2011 The FreeBSD Foundation
6  * All rights reserved.
7  * Portions of this software were developed by David Chisnall
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $FreeBSD: head/lib/libc/stdio/ungetwc.c 227753 2011-11-20 14:45:42Z theraven $
32  */
33 
34 
35 #include "namespace.h"
36 #include <errno.h>
37 #include <limits.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <wchar.h>
41 #include "un-namespace.h"
42 #include "libc_private.h"
43 #include "local.h"
44 #include "mblocal.h"
45 #include "xlocale_private.h"
46 
47 /*
48  * Non-MT-safe version.
49  */
50 wint_t
51 __ungetwc(wint_t wc, FILE *fp, locale_t locale)
52 {
53 	char buf[MB_LEN_MAX];
54 	size_t len;
55 	struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
56 	struct wchar_io_data *wcio;
57 	mbstate_t *st;
58 
59 	ORIENT(fp,1);
60 	wcio = WCIO_GET(fp);
61 
62 	if (wc == WEOF)
63 		return (WEOF);
64 	if (wcio == NULL) {
65 		return (WEOF);
66 	}
67 	wcio->wcio_ungetwc_inbuf = 0;
68 	st = &wcio->wcio_mbstate_out;
69 	if ((len = l->__wcrtomb(buf, wc, st)) == (size_t)-1) {
70 		fp->pub._flags |= __SERR;
71 		return (WEOF);
72 	}
73 	while (len-- != 0)
74 		if (__ungetc((unsigned char)buf[len], fp) == EOF)
75 			return (WEOF);
76 
77 	return (wc);
78 }
79 
80 /*
81  * MT-safe version.
82  */
83 wint_t
84 ungetwc_l(wint_t wc, FILE *fp, locale_t locale)
85 {
86 	wint_t r;
87 	FIX_LOCALE(locale);
88 
89 	FLOCKFILE(fp);
90 	ORIENT(fp, 1);
91 	r = __ungetwc(wc, fp, locale);
92 	FUNLOCKFILE(fp);
93 
94 	return (r);
95 }
96 wint_t
97 ungetwc(wint_t wc, FILE *fp)
98 {
99 	return ungetwc_l(wc, fp, __get_locale());
100 }
101