/*
 * (c) Copyright 1990 Conor P. Cahill (uunet!virtech!cpcahil).  
 * You may copy, distribute, and use this software as long as this
 * copyright statement is not removed.
 */

#ifndef lint
static
char rcs_hdr[] = "$Id: memory.c,v 1.2 2006/07/25 10:09:19 rt Exp $";
#endif

void malloc_check_data();

char *
memccpy(ptr1, ptr2, ch, len)
	register char	* ptr1;
	register char	* ptr2;
	int		  len;
	int		  ch;
{
	int		  check;
	register int	  i;
	char		* rtn;

	/*
	 * I know that the assignment could be done in the following, but
	 * I wanted to perform a check before any assignment, so first I 
	 * determine the length, check the pointers and then do the assignment.
	 */
	for( i=0; (i < len) && (ptr2[i] != ch); i++)
	{
	}
	if( ptr2[i] == ch )
	{
		check = i+1;
	}
	else
	{
		check = len;
	}

	malloc_check_data("memccpy", ptr1, check);
	malloc_check_data("memccpy", ptr2, check);

	/*
	 * if we found the character...
 	 */

	if( i < len )
	{
		rtn = ptr1+i+1;
		i++;
	}
	else
	{
		rtn = (char *) 0;
	}

 	while( i-- )
	{
		*(ptr1++) = *(ptr2++);
	}
	
	return(rtn);
}

char *
memchr(ptr1,ch,len)
	register char	* ptr1;
	register int	  ch;
	int		  len;
{
	int		  i;

	for( i=0; (i < len) && (ptr1[i] != (char) ch); i++)
	{
	}

	malloc_check_data("memchr", ptr1, i);

	if( i < len )
	{
		return( ptr1+i );
	}
	else
	{
		return( (char *) 0);	
	}
}

char *
memcpy(ptr1, ptr2, len)
	register char	* ptr1;
	register char	* ptr2;
	register int	  len;
{
	char		* rtn = ptr1;

	malloc_check_data("memcpy", ptr1, len);
	malloc_check_data("memcpy", ptr2, len);

	/*
	 * while the normal memcpy does not guarrantee that it will 
	 * handle overlapping memory correctly, we will try...
	 */
	if( ptr1 > ptr2  && ptr1 < (ptr2+len))
	{
		ptr1 += (len-1);
		ptr2 += (len-1);
		while( len-- > 0 )
		{
			*(ptr1--) = *(ptr2--);
		}
	}
	else
	{
		while( len-- > 0 )
		{
			*(ptr1++) = *(ptr2++);
		}
	}
	
	return(rtn);
}

int
memcmp(ptr1, ptr2, len)
	register char	* ptr1;
	register char	* ptr2;
	register int	  len;
{
	malloc_check_data("memcpy", ptr1, len);
	malloc_check_data("memcpy", ptr2, len);

	while( --len >= 0  && (*ptr1 == *ptr2) )
	{
		ptr1++;
		ptr2++;
	}

	/* 
	 * If stopped by len, return zero
	 */
	if( len < 0 )
	{
		return(0);
	}

	return( *ptr1 - *ptr2 );
}

char * 
memset(ptr1, ch, len)
	register char	* ptr1;
	register int	  ch;
	register int	  len;
{
	char		* rtn = ptr1;

	malloc_check_data("memcpy", ptr1, len);

	while( len-- )
	{
		*(ptr1++) = ch;
	}

	return(rtn);
}

char *
bcopy(ptr2,ptr1,len)
	char		* ptr2;
	char		* ptr1;
	int		  len;
{
	return(memcpy(ptr1,ptr2,len));
}

char *
bzero(ptr1,len)
	char		* ptr1;
	int		  len;
{
	return(memset(ptr1,'\0',len));
}

int
bcmp(ptr2, ptr1, len)
	char		* ptr1;
	char		* ptr2;
	int		  len;
{
	return( memcmp(ptr1,ptr2,len) );
}