incubator-nuttx/libs/libc/dirent/lib_alphasort.c

76 lines
3.0 KiB
C

/****************************************************************************
* libs/libc/dirent/lib_alphasort.c
*
* Copyright (C) 2019 Gregory Nutt. All rights reserved.
* Author: Michael Jung <mijung@gmx.net>
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <dirent.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: alphasort
*
* Description:
* The alphasort() function can be used as the comparison function compar()
* for scandir(). It sorts directory entries using strcoll on the strings
* (*a)->d_name and (*b)->d_name.
*
* Input Parameters:
* a - The first direntry to compare
* b - The second direntry to compare
*
* Returned Value:
* An integer less than, equal to, or greater than zero if the first
* argument is considered to be respectively less than, equal to, or greater
* than the second.
*
****************************************************************************/
int alphasort(FAR const struct dirent **a, FAR const struct dirent **b)
{
#ifdef CONFIG_LIBC_LOCALE
return strcoll((*a)->d_name, (*b)->d_name);
#else
return strcmp((*a)->d_name, (*b)->d_name);
#endif
}