* libs/libc/wchar/lib_mbsnrtowcs.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
* Included Files
****************************************************************************/
#include <wchar.h>
* Public Functions
****************************************************************************/
* Name: mbsnrtowcs
*
* Description:
* The 'mbsrtowcs' function converts a sequence of multibyte characters
* pointed to indirectly by 'src' into a sequence of corresponding wide
* characters and stores at most 'len' of them in the wchar_t array pointed
* to by 'dst', until it encounters a terminating null character ('\0').
*
* If 'dst' is NULL, no characters are stored.
*
* If 'dst' is not NULL, the pointer pointed to by 'src' is updated to
* point to the character after the one that conversion stopped at. If
* conversion stops because a null character is encountered, *'src' is set
* to NULL.
*
* The mbstate_t argument, 'ps', is used to keep track of the shift state.
* If it is NULL, 'mbsrtowcs' uses an internal, static mbstate_t object,
* which is initialized to the initial conversion state at program startup.
*
* The 'mbsnrtowcs' function behaves identically to 'mbsrtowcs', except
* that conversion stops after reading at most 'nms' bytes from the buffer
* pointed to by 'src'.
*
* Returned Value:
* The 'mbsrtowcs' and 'mbsnrtowcs' functions return the number of wide
* characters stored in the array pointed to by 'dst' if successful,
* otherwise it returns (size_t)-1.
*
* Portability:
* 'mbsrtowcs' is defined by the C99 standard.
* 'mbsnrtowcs' is defined by the POSIX.1-2008 standard.
*
****************************************************************************/
size_t mbsnrtowcs(FAR wchar_t *dst, FAR const char **src, size_t nms,
size_t len, FAR mbstate_t *ps)
{
FAR const char *s = *src;
FAR wchar_t *ws = dst;
size_t cnt = 0;
size_t l;
if (dst == NULL)
{
len = SIZE_MAX;
}
if (s != NULL)
{
while (len > 0 && nms > 0)
{
l = mbrtowc(ws, s, nms, ps);
if ((ssize_t)l <= 0)
{
if ((ssize_t)l == -2)
{
* stops at the end of the input buffer.
*/
s += nms;
}
else if (l == 0)
{
s = NULL;
}
else
{
cnt = l;
}
break;
}
s += l;
nms -= l;
if (ws != NULL)
{
ws++;
}
len--;
cnt++;
}
}
if (dst != NULL)
{
*src = s;
}
return cnt;
}