78 lines
2.8 KiB
C
78 lines
2.8 KiB
C
/****************************************************************************
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* libs/libc/string/lib_strndup.c
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <string.h>
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#include "libc.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: strndup
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*
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* Description:
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* The strndup() function is equivalent to the strdup() function,
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* duplicating the provided 's' in a new block of memory allocated as
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* if by using malloc(), with the exception being that strndup() copies
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* at most 'size' plus one bytes into the newly allocated memory,
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* terminating the new string with a NUL character. If the length of 's'
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* is larger than 'size', only 'size' bytes will be duplicated. If
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* 'size' is larger than the length of 's', all bytes in s will be
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* copied into the new memory buffer, including the terminating NUL
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* character. The newly created string will always be properly
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* terminated.
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*
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****************************************************************************/
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#undef strndup /* See mm/README.txt */
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FAR char *strndup(FAR const char *s, size_t size)
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{
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FAR char *news = NULL;
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/* Get the size of the new string (limited to size) */
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size_t allocsize = strnlen(s, size);
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/* Allocate the new string, adding 1 for the NUL terminator */
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news = (FAR char *)lib_malloc(allocsize + 1);
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if (news)
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{
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/* Copy the string into the allocated memory and add a NUL
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* terminator in any case.
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*/
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memcpy(news, s, allocsize);
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news[allocsize] = '\0';
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}
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return news;
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}
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