windows-nt/Source/XPSP1/NT/base/crts/crtw32/string/memicmp.c
2020-09-26 16:20:57 +08:00

135 lines
4 KiB
C

/***
*memicmp.c - compare memory, ignore case
*
* Copyright (c) 1988-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines _memicmp() - compare two blocks of memory for lexical
* order. Case is ignored in the comparison.
*
*Revision History:
* 05-31-89 JCR C version created.
* 02-27-90 GJF Fixed calling type, #include <cruntime.h>, fixed
* copyright. Also, fixed compiler warnings.
* 10-01-90 GJF New-style function declarator. Also, rewrote expr. to
* avoid using cast as an lvalue.
* 01-17-91 GJF ANSI naming.
* 10-11-91 GJF Bug fix! Comparison of final bytes must use unsigned
* chars.
* 09-01-93 GJF Replaced _CALLTYPE1 with __cdecl.
* 10-18-94 GJF Sped up, especially for C locale. Also, made multi-
* thread safe.
* 12-29-94 CFW Merge non-Win32.
* 09-26-95 GJF New locking macro, and scheme, for functions which
* reference the locale.
* 11-15-95 BWT Fix _NTSUBSET_
* 08-27-98 GJF Revised multithread support based on threadlocinfo
* struct.
* 09-08-98 GJF Split out ASCII-only version.
* 05-17-99 PML Remove all Macintosh support.
* 10-27-99 PML Win64 fix: unsigned int -> size_t
* 26-01-00 GB Modified memicmp for performance.
* 09-03-00 GB Moved the performance code to toupper and tolower.
* restored the original file.
*
*******************************************************************************/
#include <cruntime.h>
#include <string.h>
#include <mtdll.h>
#include <ctype.h>
#include <setlocal.h>
#include <locale.h>
/***
*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
* size_t count - maximum length to compare
*
*Exit:
* returns < 0 if first < last
* returns 0 if first == last
* returns > 0 if first > last
*
*Uses:
*
*Exceptions:
*
*******************************************************************************/
int __cdecl _memicmp (
const void * first,
const void * last,
size_t count
)
{
int f = 0, l = 0;
const char *dst = first, *src = last;
#if !defined(_NTSUBSET_)
#ifdef _MT
pthreadlocinfo ptloci = _getptd()->ptlocinfo;
if ( ptloci != __ptlocinfo )
ptloci = __updatetlocinfo();
if ( ptloci->lc_handle[LC_CTYPE] == _CLOCALEHANDLE )
#else
if ( __lc_handle[LC_CTYPE] == _CLOCALEHANDLE )
#endif
{
#endif /* !_NTSUBSET_ */
return __ascii_memicmp(first, last, count);
#if !defined(_NTSUBSET_)
}
else {
while (count-- && f==l)
{
#ifdef _MT
f = __tolower_mt( ptloci, (unsigned char)(*(dst++)) );
l = __tolower_mt( ptloci, (unsigned char)(*(src++)) );
#else
f = tolower( (unsigned char)(*(dst++)) );
l = tolower( (unsigned char)(*(src++)) );
#endif
}
}
#endif /* !_NTSUBSET_ */
return ( f - l );
}
#ifndef _M_IX86
int __cdecl __ascii_memicmp (
const void * first,
const void * last,
size_t count
)
{
int f = 0;
int l = 0;
while ( count-- )
{
if ( (*(unsigned char *)first == *(unsigned char *)last) ||
((f = __ascii_tolower( *(unsigned char *)first )) ==
(l = __ascii_tolower( *(unsigned char *)last ))) )
{
first = (char *)first + 1;
last = (char *)last + 1;
}
else
break;
}
return ( f - l );
}
#endif