108 lines
3.9 KiB
C
108 lines
3.9 KiB
C
/****************************************************************************
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* libs/libc/string/lib_stpncpy.c
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*
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* Copyright (C) 2018 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/types.h>
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#include <string.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: stpncpy
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*
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* Description:
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* Copies the string pointed to by 'src' (including the terminating NUL
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* character) into the array pointed to by 'dest'. strncpy() will not
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* copy more than 'n' bytes from 'src' to 'dest' array (including the
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* NUL terminator).
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*
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* If the array pointed to by 'src' is a string that is shorter than 'n'
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* bytes, NUL characters will be appended to the copy in the array
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* pointed to by 'dest', until 'n' bytes in all are written.
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*
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* If copying takes place between objects that overlap, the behavior is
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* undefined.
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*
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* Returned Value:
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* If a NUL character is written to the destination, the stpncpy()
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* function will return the address of the first such NUL character.
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* Otherwise, it will return &dest[n]
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*
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****************************************************************************/
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#ifndef CONFIG_LIBC_ARCH_STPNCPY
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FAR char *stpncpy(FAR char *dest, FAR const char *src, size_t n)
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{
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FAR char *end = dest + n; /* End of dest buffer + 1 byte */
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FAR char *ret; /* Value to be returned */
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/* Copy up n bytes, breaking out of the loop early if a NUL terminator is
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* encountered.
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*/
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while ((dest != end) && (*dest = *src++) != '\0')
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{
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/* Increment the 'dest' pointer only if it does not refer to the
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* NUL terminator.
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*/
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dest++;
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}
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/* Return the pointer to the NUL terminator (or to the end of the buffer
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* + 1).
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*/
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ret = dest;
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/* Pad the remainder of the array pointer to 'dest' with NULs. This
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* overwrites any previously copied NUL terminator.
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*/
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while (dest != end)
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{
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*dest++ = '\0';
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}
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return ret;
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}
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#endif
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