vswprintf.c revision 1.3 
1/*	$OpenBSD: vswprintf.c,v 1.3 2011/04/28 17:38:46 stsp Exp $	*/
2/*	$NetBSD: vswprintf.c,v 1.1 2005/05/14 23:51:02 christos Exp $	*/
3
4/*
5 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
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 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
20 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
21 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
22 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
25 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
27 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
28 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32#include <errno.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36#include <wchar.h>
37#include <stdarg.h>
38#include "local.h"
39
40int
41vswprintf(wchar_t * __restrict s, size_t n, const wchar_t * __restrict fmt,
42    __va_list ap)
43{
44	mbstate_t mbs;
45	FILE f;
46	char *mbp;
47	int ret, sverrno;
48	size_t nwc;
49	struct __sfileext fext;
50
51	if (n == 0) {
52		errno = EINVAL;
53		return (-1);
54	}
55
56	_FILEEXT_SETUP(&f, &fext);
57	f._file = -1;
58	f._flags = __SWR | __SSTR | __SALC;
59	f._bf._base = f._p = (unsigned char *)malloc(128);
60	if (f._bf._base == NULL) {
61		errno = ENOMEM;
62		return (-1);
63	}
64	f._bf._size = f._w = 127;		/* Leave room for the NUL */
65	ret = __vfwprintf(&f, fmt, ap);
66	if (ret < 0) {
67		sverrno = errno;
68		free(f._bf._base);
69		errno = sverrno;
70		return (-1);
71	}
72	if (ret == 0) {
73		s[0] = L'\0';
74		free(f._bf._base);
75		return (0);
76	}
77	*f._p = '\0';
78	mbp = (char *)f._bf._base;
79	/*
80	 * XXX Undo the conversion from wide characters to multibyte that
81	 * fputwc() did in __vfwprintf().
82	 */
83	bzero(&mbs, sizeof(mbs));
84	nwc = mbsrtowcs(s, (const char **)&mbp, n, &mbs);
85	free(f._bf._base);
86	if (nwc == (size_t)-1) {
87		errno = EILSEQ;
88		return (-1);
89	}
90	if (nwc == n) {
91		s[n - 1] = L'\0';
92		errno = EOVERFLOW;
93		return (-1);
94	}
95
96	return (ret);
97}
98