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

69 lines
2.2 KiB
C

/****************************************************************************
* libs/libc/string/lib_strchr.c
*
* 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: strchr
*
* Description:
* The strchr() function locates the first occurrence of 'c' (converted to
* a char) in the string pointed to by 's'. The terminating null byte is
* considered to be part of the string.
*
* Returned Value:
* Upon completion, strchr() returns a pointer to the byte, or a null
* pointer if the byte was not found.
*
****************************************************************************/
#if !defined(CONFIG_LIBC_ARCH_STRCHR) && defined(LIBC_BUILD_STRING)
#undef strchr /* See mm/README.txt */
FAR char *strchr(FAR const char *s, int c)
{
for (; ; s++)
{
if (*s == c)
{
return (FAR char *)s;
}
if (*s == 0)
{
break;
}
}
return NULL;
}
#endif