windows-nt/Source/XPSP1/NT/com/ole32/stg/async/cruntime.cxx

//+---------------------------------------------------------------------------
//
//  Microsoft Windows
//  Copyright (C) Microsoft Corporation, 1992 - 1996.
//
//  File:	cruntime.cxx
//
//  Contents:	Implementation of Cruntimes that we need since we
//              can't use MSVCRT and WIn95 doesn't implement the lstr*W 
//              versions. (well, it implements them but they are just stubs)
//
//
//  Functions:	Laylstrcmp
//              Laylstrcpy
//              Laylstrcpyn
//              Laylstrlen
//              Laylstrcat
//
//  History:	20-Jun-96	SusiA	Created
//
//----------------------------------------------------------------------------

#pragma hdrstop
#include <string.h>

/***
* Laylstrcmp - compare two wchar_t strings,
*	 returning less than, equal to, or greater than
*
*Purpose:
*	wcscmp compares two wide-character 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 wchar_t by wchar_t on an UNSIGNED basis, which is to
*	say that Null wchar_t(0) is less than any other character.
*
*Entry:
*	const wchar_t * src - string for left-hand side of comparison
*	const wchar_t * 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 Laylstrcmp (
	const wchar_t * src,
	const wchar_t * dst
	)
{
	int ret = 0 ;

	while( ! (ret = (int)(*src - *dst)) && *dst)
		++src, ++dst;

	if ( ret < 0 )
		ret = -1 ;
	else if ( ret > 0 )
		ret = 1 ;

	return( ret );
}


/***
*wchar_t *Laylstrcat(dst, src) - concatenate (append) one wchar_t string to another
*
*Purpose:
*	Concatenates src onto the end of dest.	Assumes enough
*	space in dest.
*
*Entry:
*	wchar_t *dst - wchar_t string to which "src" is to be appended
*	const wchar_t *src - wchar_t string to be appended to the end of "dst"
*
*Exit:
*	The address of "dst"
*
*Exceptions:
*
*******************************************************************************/

wchar_t * Laylstrcat (
	wchar_t * dst,
	const wchar_t * src
	)
{
	wchar_t * cp = dst;

	while( *cp )
		cp++;			/* find end of dst */

	while( *cp++ = *src++ ) ;	/* Copy src to end of dst */

	return( dst );			/* return dst */

}


/***
*wchar_t *Laylstrcpy(dst, src) - copy one wchar_t string over another
*
*Purpose:
*	Copies the wchar_t string src into the spot specified by
*	dest; assumes enough room.
*
*Entry:
*	wchar_t * dst - wchar_t string over which "src" is to be copied
*	const wchar_t * src - wchar_t string to be copied over "dst"
*
*Exit:
*	The address of "dst"
*
*Exceptions:
*******************************************************************************/

wchar_t * Laylstrcpy(wchar_t * dst, const wchar_t * src)
{
	wchar_t * cp = dst;

	while( *cp++ = *src++ )
		;		/* Copy src over dst */

	return( dst );
}


/***
*wchar_t *Laylstrcpyn(dest, source, count) - copy at most n wide characters
*
*Purpose:
*	Copies count characters from the source string to the
*	destination.  If count is less than the length of source,
*	NO NULL CHARACTER is put onto the end of the copied string.
*	If count is greater than the length of sources, dest is padded
*	with null characters to length count (wide-characters).
*
*
*Entry:
*	wchar_t *dest - pointer to destination
*	wchar_t *source - source string for copy
*	size_t count - max number of characters to copy
*
*Exit:
*	returns dest
*
*Exceptions:
*
*******************************************************************************/


wchar_t * Laylstrcpyn (
	wchar_t * dest,
	const wchar_t * source,
	size_t count
	)
{
	wchar_t *start = dest;

	while (count && (*dest++ = *source++))	  /* copy string */
		count--;

	if (count)				/* pad out with zeroes */
		while (--count)
			*dest++ = L'\0';

	return(start);
}

/***
*Laylstrlen - return the length of a null-terminated wide-character string
*
*Purpose:
*	Finds the length in wchar_t's of the given string, not including
*	the final null wchar_t (wide-characters).
*
*Entry:
*	const wchar_t * wcs - string whose length is to be computed
*
*Exit:
*	length of the string "wcs", exclusive of the final null wchar_t
*
*Exceptions:
*
*******************************************************************************/

size_t Laylstrlen (
	const wchar_t * wcs
	)
{
	const wchar_t *eos = wcs;

	while( *eos++ ) ;

	return( (size_t)(eos - wcs - 1) );
}