xref: /freebsd/lib/libc/locale/mblen.c (revision 10b59a9b4add0320d52c15ce057dd697261e7dfc)
1  /*-
2   * Copyright (c) 2002-2004 Tim J. Robbins.
3   * All rights reserved.
4   *
5   * Redistribution and use in source and binary forms, with or without
6   * modification, are permitted provided that the following conditions
7   * are met:
8   * 1. Redistributions of source code must retain the above copyright
9   *    notice, this list of conditions and the following disclaimer.
10   * 2. Redistributions in binary form must reproduce the above copyright
11   *    notice, this list of conditions and the following disclaimer in the
12   *    documentation and/or other materials provided with the distribution.
13   *
14   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24   * SUCH DAMAGE.
25   */
26  
27  #include <sys/cdefs.h>
28  __FBSDID("$FreeBSD$");
29  
30  #include <stdlib.h>
31  #include <wchar.h>
32  #include "mblocal.h"
33  
34  int
35  mblen(const char *s, size_t n)
36  {
37  	static const mbstate_t initial;
38  	static mbstate_t mbs;
39  	size_t rval;
40  
41  	if (s == NULL) {
42  		/* No support for state dependent encodings. */
43  		mbs = initial;
44  		return (0);
45  	}
46  	rval = __mbrtowc(NULL, s, n, &mbs);
47  	if (rval == (size_t)-1 || rval == (size_t)-2)
48  		return (-1);
49  	return ((int)rval);
50  }
51