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UbixOS / Dump / hybos / lib / mem / memicmp.c
@cwolsen cwolsen on 31 Oct 2018 1 KB Big Dump
/***
*memicmp.c - compare memory, ignore case
*
*   Copyright (c) 1988-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       defines _memicmp() - compare two blocks of memory for lexical
*       order.  Case is ignored in the comparison.
*
*******************************************************************************/


#define _TOLOWER(c) ( ((c) >= 'A') && ((c) <= 'Z') ? ((c) - 'A' + 'a') :\
              (c) )

/***
*int _memicmp(first, last, count) - compare two blocks of memory, ignore case
*
*Purpose:
*   Compares count bytes of the two blocks of memory stored at first
*   and last.  The characters are converted to lowercase before
*   comparing (not permanently), so case is ignored in the search.
*
*Entry:
*   char *first, *last - memory buffers to compare
*   unsigned count - maximum length to compare
*
*Exit:
*   returns < 0 if first < last
*   returns 0 if first == last
*   returns > 0 if first > last
*
*Uses:
*
*Exceptions:
*
*******************************************************************************/

int _memicmp(const void * first, const void * last, unsigned int count)
{
	int f = 0;
	int l = 0;

	while(count--)
	{
		if((*(unsigned char *)first == *(unsigned char *)last) ||
				((f = _TOLOWER( *(unsigned char *)first)) ==
				(l = _TOLOWER( *(unsigned char *)last))))
		{
			first = (char *)first + 1;
			last = (char *)last + 1;
		}
		else
			break;
	}

	return (f - l);
}