1 /* $OpenBSD: ungetwc.c,v 1.5 2011/10/16 13:20:51 stsp Exp $ */
2 /* $NetBSD: ungetwc.c,v 1.2 2003/01/18 11:29:59 thorpej Exp $ */
3
4 /*-
5 * Copyright (c)2001 Citrus Project,
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $Citrus$
30 */
31
32 #include <errno.h>
33 #include <stdio.h>
34 #include <wchar.h>
35 #include "local.h"
36
37 wint_t
__ungetwc(wint_t wc,FILE * fp)38 __ungetwc(wint_t wc, FILE *fp)
39 {
40 struct wchar_io_data *wcio;
41
42 if (wc == WEOF)
43 return WEOF;
44
45 _SET_ORIENTATION(fp, 1);
46 /*
47 * XXX since we have no way to transform a wchar string to
48 * a char string in reverse order, we can't use ungetc.
49 */
50 /* XXX should we flush ungetc buffer? */
51
52 wcio = WCIO_GET(fp);
53 if (wcio == 0) {
54 errno = ENOMEM; /* XXX */
55 return WEOF;
56 }
57
58 if (wcio->wcio_ungetwc_inbuf >= WCIO_UNGETWC_BUFSIZE) {
59 return WEOF;
60 }
61
62 wcio->wcio_ungetwc_buf[wcio->wcio_ungetwc_inbuf++] = wc;
63 __sclearerr(fp);
64
65 return wc;
66 }
67
68 wint_t
ungetwc(wint_t wc,FILE * fp)69 ungetwc(wint_t wc, FILE *fp)
70 {
71 wint_t r;
72
73 FLOCKFILE(fp);
74 r = __ungetwc(wc, fp);
75 FUNLOCKFILE(fp);
76 return (r);
77 }
78