79 lines
2.7 KiB
C
79 lines
2.7 KiB
C
/****************************************************************************
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* libs/libc/string/lib_memccpy.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 <sys/types.h>
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#include <string.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: memccpy
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*
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* Description:
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* The memccpy() function copies bytes from memory area s2 into s1,
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* stopping after the first occurrence of byte c (converted to an unsigned
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* char) is copied, or after n bytes are copied, whichever comes first. If
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* copying takes place between objects that overlap, the behavior is
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* undefined.
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*
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* Returned Value:
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* The memccpy() function returns a pointer to the byte after the copy of c
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* in s1, or a null pointer if c was not found in the first n bytes of s2.
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*
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****************************************************************************/
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#undef memccpy /* See mm/README.txt */
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FAR void *memccpy(FAR void *s1, FAR const void *s2, int c, size_t n)
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{
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FAR unsigned char *pout = (FAR unsigned char *)s1;
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FAR unsigned char *pin = (FAR unsigned char *)s2;
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/* Copy at most n bytes */
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while (n-- > 0)
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{
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/* Copy one byte */
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*pout = *pin++;
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/* Did we just copy the terminating byte c? */
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if (*pout++ == (unsigned char)c)
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{
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/* Yes return a pointer to the byte after the copy of c into s1 */
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return (FAR void *)pout;
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}
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}
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/* C was not found in the first n bytes of s2 */
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return NULL;
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}
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