119 lines
4.1 KiB
C
119 lines
4.1 KiB
C
/****************************************************************************
|
|
* libs/libc/string/lib_strndup.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 <nuttx/config.h>
|
|
|
|
#include <string.h>
|
|
|
|
#include "libc.h"
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: nx_strndup
|
|
*
|
|
* Description:
|
|
* The strndup() function is equivalent to the strdup() function,
|
|
* duplicating the provided 's' in a new block of memory allocated as
|
|
* if by using kmm_malloc(), with the exception being that strndup() copies
|
|
* at most 'size' plus one bytes into the newly allocated memory,
|
|
* terminating the new string with a NUL character. If the length of 's'
|
|
* is larger than 'size', only 'size' bytes will be duplicated. If
|
|
* 'size' is larger than the length of 's', all bytes in s will be
|
|
* copied into the new memory buffer, including the terminating NUL
|
|
* character. The newly created string will always be properly
|
|
* terminated.
|
|
*
|
|
****************************************************************************/
|
|
|
|
FAR char *nx_strndup(FAR const char *s, size_t size)
|
|
{
|
|
FAR char *news;
|
|
|
|
/* Get the size of the new string (limited to size) */
|
|
|
|
size_t allocsize = strnlen(s, size);
|
|
|
|
/* Allocate the new string, adding 1 for the NUL terminator */
|
|
|
|
news = (FAR char *)kmm_malloc(allocsize + 1);
|
|
if (news != NULL)
|
|
{
|
|
/* Copy the string into the allocated memory and add a NUL
|
|
* terminator in any case.
|
|
*/
|
|
|
|
memcpy(news, s, allocsize);
|
|
news[allocsize] = '\0';
|
|
}
|
|
|
|
return news;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: strndup
|
|
*
|
|
* Description:
|
|
* The strndup() function is equivalent to the strdup() function,
|
|
* duplicating the provided 's' in a new block of memory allocated as
|
|
* if by using malloc(), with the exception being that strndup() copies
|
|
* at most 'size' plus one bytes into the newly allocated memory,
|
|
* terminating the new string with a NUL character. If the length of 's'
|
|
* is larger than 'size', only 'size' bytes will be duplicated. If
|
|
* 'size' is larger than the length of 's', all bytes in s will be
|
|
* copied into the new memory buffer, including the terminating NUL
|
|
* character. The newly created string will always be properly
|
|
* terminated.
|
|
*
|
|
****************************************************************************/
|
|
|
|
#undef strndup /* See mm/README.txt */
|
|
FAR char *strndup(FAR const char *s, size_t size)
|
|
{
|
|
FAR char *news = NULL;
|
|
|
|
/* Get the size of the new string (limited to size) */
|
|
|
|
size_t allocsize = strnlen(s, size);
|
|
|
|
/* Allocate the new string, adding 1 for the NUL terminator */
|
|
|
|
news = (FAR char *)lib_malloc(allocsize + 1);
|
|
if (news)
|
|
{
|
|
/* Copy the string into the allocated memory and add a NUL
|
|
* terminator in any case.
|
|
*/
|
|
|
|
memcpy(news, s, allocsize);
|
|
news[allocsize] = '\0';
|
|
}
|
|
|
|
return news;
|
|
}
|