newlib-cygwin/newlib/libc/string/wcsnlen.c

70 lines
2.1 KiB
C

/*
FUNCTION
<<wcsnlen>>---get fixed-size wide-character string length
INDEX
wcsnlen
SYNOPSIS
#include <wchar.h>
size_t wcsnlen(const wchar_t *<[s]>, size_t <[maxlen]>);
DESCRIPTION
The <<wcsnlen>> function computes the number of wide-character codes
in the wide-character string pointed to by <[s]> not including the
terminating L'\0' wide character but at most <[maxlen]> wide
characters.
RETURNS
<<wcsnlen>> returns the length of <[s]> if it is less then <[maxlen]>,
or <[maxlen]> if there is no L'\0' wide character in first <[maxlen]>
characters.
PORTABILITY
<<wcsnlen>> is a GNU extension.
<<wcsnlen>> requires no supporting OS subroutines.
*/
/*
* Copyright (c) 2003, Artem B. Bityuckiy (dedekind@mail.ru).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the above copyright notice,
* this condition statement, and the following disclaimer are retained
* in any redistributions of the source code.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <_ansi.h>
#include <sys/types.h>
#include <wchar.h>
size_t
_DEFUN(wcsnlen, (s, maxlen),
const wchar_t *s,
size_t maxlen)
{
const wchar_t *p;
p = s;
while (*p && maxlen-- > 0)
p++;
return (size_t)(p - s);
}