incubator-nuttx/libs/libc/wchar/lib_wcsncmp.c

63 lines
2.5 KiB
C

/****************************************************************************
* libs/libc/wchar/lib_wcsncmp.c
*
* Copyright © 2005-2014 Rich Felker, et al.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <wchar.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: wcsncmp
*
* Description:
* Compares up to "n" characters of the C wide string "l" to those of
* the C wide string "r".
*
* Input Parameters:
* l - the wchar string to be compared
* r - the wchar string to be compared
* n - maximum number of wide characters to be compared
*
* Returned Value:
* Return 0 if the characters compared in both strings form the same
* string.
* Return value greater than 0 if the first character that does not match
* has a greater value in "l" than in "r"
* Reutrn value less than 0 otherswise
*
****************************************************************************/
int wcsncmp(FAR const wchar_t *l, FAR const wchar_t *r, size_t n)
{
for (; n && *l == *r && *l && *r; n--, l++, r++);
return n ? *l - *r : 0;
}