nuttx/libs/libc/string/lib_strchr.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_STRCHR)
#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