incubator-nuttx/libs/libc/string/lib_rawmemchr.c

62 lines
2.4 KiB
C

/****************************************************************************
* libs/libc/string/lib_rawmemchr.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>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: rawmemchr
*
* Description:
* The rawmemchr() function is similar to memchr(), it assumes (i.e., the
* programmer knows for certain) that an instance of c lies somewhere in
* the memory area starting at the location pointed to by s,and so performs
* an optimized search for c (i.e., no use of a count argument to limit the
* range of the search). If an instance of c is not found, the results are
* unpredictable.The following call is a fast means of locating a string's
* terminating null byte.
*
* Returned Value:
* The rawmemchr() function returns a pointer to the located byte, or a
* null pointer if the byte does not occur in the object.
*
****************************************************************************/
FAR void *rawmemchr(FAR const void *s, int c)
{
if (c != '\0')
{
return memchr(s, c, SSIZE_MAX);
}
return (FAR char *)s + strlen(s);
}