incubator-nuttx/libs/libc/wchar/lib_wcrtomb.c

78 lines
2.4 KiB
C

/****************************************************************************
* libs/libc/wchar/lib_wcrtomb.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>
#include <errno.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: wcrtomb
*
* Description:
* Convert a wide character to a multibyte sequence
*
****************************************************************************/
size_t wcrtomb(FAR char *s, wchar_t wc, FAR mbstate_t *ps)
{
if (s == NULL)
{
return 0;
}
else if ((unsigned)wc < 0x80)
{
*s = wc;
return 1;
}
else if ((unsigned)wc < 0x800)
{
*s++ = 0xc0 | (wc >> 6);
*s = 0x80 | (wc & 0x3f);
return 2;
}
else if ((unsigned)wc < 0xd800 || (unsigned)wc <= 0xffff)
{
*s++ = 0xe0 | (wc >> 12);
*s++ = 0x80 | ((wc >> 6) & 0x3f);
*s = 0x80 | (wc & 0x3f);
return 3;
}
else if ((unsigned long)wc < 0x110000)
{
*s++ = 0xf0 | ((unsigned long)wc >> 18);
*s++ = 0x80 | ((wc >> 12) & 0x3f);
*s++ = 0x80 | ((wc >> 6) & 0x3f);
*s = 0x80 | (wc & 0x3f);
return 4;
}
set_errno(EILSEQ);
return -1;
}