/*** *strcmp - compare two strings, returning less than, equal to, or greater than * *Purpose: * STRCMP compares two strings and returns an integer * to indicate whether the first is less than the second, the two are * equal, or whether the first is greater than the second. * * Comparison is done byte by byte on an UNSIGNED basis, which is to * say that Null (0) is less than any other character (1-255). * *Entry: * const char * src - string for left-hand side of comparison * const char * dst - string for right-hand side of comparison * *Exit: * returns -1 if src < dst * returns 0 if src == dst * returns +1 if src > dst * *Exceptions: * *******************************************************************************/
int __cdecl strcmp ( const char * src, const char * dst )
{ int ret = 0 ;
while( ! (ret = *(unsigned char *)src - *(unsigned char *)dst) && *dst) //直到src和dst当前数值不相等且dst不为\0时退出while ++src, ++dst;
if ( ret < 0 ) ret = -1 ;
else if ( ret > 0 ) ret = 1 ; return( ret );
}
