px4-firmware/nuttx/lib/string/lib_memccpy.c

100 lines
3.7 KiB
C

/****************************************************************************
* lib/string/lib_memccpy.c
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in 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 in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* 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.
*
****************************************************************************/
/****************************************************************************
* Compilation Switches
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <string.h>
/****************************************************************************
* Global Functions
****************************************************************************/
/****************************************************************************
* Name: memccpy
*
* Description:
* The memccpy() function copies bytes from memory area s2 into s1,
* stopping after the first occurrence of byte c (converted to an unsigned
* char) is copied, or after n bytes are copied, whichever comes first. If
* copying takes place between objects that overlap, the behavior is
* undefined.
*
* Returned Value:
* The memccpy() function returns a pointer to the byte after the copy of c
* in s1, or a null pointer if c was not found in the first n bytes of s2.
*
****************************************************************************/
FAR void *memccpy(FAR void *s1, FAR const void *s2, int c, size_t n)
{
FAR unsigned char *pout = (FAR unsigned char*)s1;
FAR unsigned char *pin = (FAR unsigned char*)s2;
/* Copy at most n bytes */
while (n-- > 0)
{
/* Copy one byte */
*pout = *pin++;
/* Did we just copy the terminating byte c? */
if (*pout == (unsigned char)c)
{
/* Yes return a pointer to the byte after the copy of c into s1 */
return (FAR void *)pout;
}
/* No increment to the next destination location */
pout++;
}
/* C was not found in the first n bytes of s2 */
return NULL;
}