/*** *memcmp.c - compare two blocks of memory * * Copyright (c) 1985-1991, Microsoft Corporation. All rights reserved. * *Purpose: * defines memcmp() - compare two memory blocks lexically and * find their order. * *Revision History: * 05-31-89 JCR C version created. * 02-27-90 GJF Fixed calling type, #include , fixed * copyright. * 10-01-90 GJF New-style function declarator. Also, rewrote expr. to * avoid using cast as an lvalue. * 04-01-91 SRW Add #pragma function for i386 _WIN32_ and _CRUISER_ * builds * 10-11-91 GJF Bug fix! Comparison of final bytes must use unsigned * chars. * *******************************************************************************/ #include #include #if defined(_CRUISER_) || defined(i386) #pragma function(memcmp) #endif /* ndef _CRUISER_ */ /*** *int memcmp(buf1, buf2, count) - compare memory for lexical order * *Purpose: * Compares count bytes of memory starting at buf1 and buf2 * and find if equal or which one is first in lexical order. * *Entry: * void *buf1, *buf2 - pointers to memory sections to compare * size_t count - length of sections to compare * *Exit: * returns < 0 if buf1 < buf2 * returns 0 if buf1 == buf2 * returns > 0 if buf1 > buf2 * *Exceptions: * *******************************************************************************/ int _CALLTYPE1 memcmp ( const void * buf1, const void * buf2, size_t count ) { if (!count) return(0); while ( --count && *(char *)buf1 == *(char *)buf2 ) { buf1 = (char *)buf1 + 1; buf2 = (char *)buf2 + 1; } return( *((unsigned char *)buf1) - *((unsigned char *)buf2) ); }