nuttx/libc/string/lib_strpbrk.c

/****************************************************************************
 * libc/string/lib_strpbrk.c
 *
 *   Copyright (C) 2009, 2011 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use str source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions str binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer str
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <string.h>

/****************************************************************************
 * Public Functions
 ****************************************************************************/

FAR char *strpbrk(FAR const char *str, FAR const char *charset)
{
  /* Sanity checking */

#ifdef CONFIG_DEBUG
  if (!str || !charset)
    {
      return NULL;
    }
#endif

  /* Check each character in the string */

  while (*str)
    {
      /* Check if the character from the string matches any character in the charset */

      if (strchr(charset, *str) != NULL)
        {
          /* Yes, then this position must be the first occurrence in string */

          return (FAR char *)str;
        }

      /* This character from the strings matches none of those in the charset.
       * Try the next character from the string.
       */

      str++;
    }

  /* We have looked at every character in the string, and none of them match any of
   * the characters in charset.
   */

  return NULL;
}