/**** Upper HALF driver routines ****/ 
int sgetc(struct stty* tty) 
{ 
	char c;
/*(1). wait for chars in inbuf[]*/
	P(&tty->inRoom);
/*(2). get a char from inbuf[]; NOTE: MUST HANDLE POSSIBLE INTERFERENCE FROM shandler()!*/
	lock();
		c = tty->inbuf[tty->inhead++];
		tty->inhead %= BUFLEN;
	unlock();
/*(3). return the char;*/
	return c;
}/*end sgetc*/

int sgetline(struct stty* tty,  char* line) 
{  
/*(1). one process at a time!
	tty = &stty[0];*/
/*(2). call sgetc() repeatedly until a line is copied to line[];*/
	while (*line)
	{
		sgetc(tty, *line++);
	}/*end while line exists*/
/*(3). allow another process.*/
	return 1;
}/*end sgetline*/