_delay.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)_delay.c	4.1	(ULTRIX)	7/2/90";
#endif lint


/************************************************************************
 *									*
 *			Copyright (c) 1988, 1990 by			*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
 
/*
 * Modification History
 *
 * 02/07/90 GWS	replaced sgttyb / tty(4)-style terminal I/O with termio(4)-
 *		 style terminal I/O.  The replacement code is the formerly
 *		 conditionalized "USG" code.
 *
 */

/* Copyright (c) 1979 Regents of the University of California */
#include <ctype.h>
#include "curses.h"
#include "term.h"
#ifdef NONSTANDARD
# include "ns_curses.h"
#endif

/*
 * The following array gives the number of tens of milliseconds per
 * character for each speed as returned by gtty.  Thus since 300
 * baud returns a 7, there are 33.3 milliseconds per char at 300 baud.
 */
static
short	tmspc10[] = {
	/* 0   50    75   110 134.5 150  200  300   baud */
	   0, 2000, 1333, 909, 743, 666, 500, 333,
	/* 600 1200 1800 2400 4800 9600 19200 38400 baud */
	   166, 83,  55,  41,  20,  10,   5,    2
};

/*
 * Insert a delay into the output stream for "delay/10" milliseconds.
 * Round up by a half a character frame, and then do the delay.
 * Too bad there are no user program accessible programmed delays.
 * Transmitting pad characters slows many terminals down and also
 * loads the system.
 */
_delay(delay, outc)
register int delay;
int (*outc)();
{
	register int mspc10;
	register int pc;
	register int outspeed;

#ifndef 	NONSTANDARD
	outspeed = cur_term->Nttyb.c_cflag&CBAUD;
#else		NONSTANDARD
	outspeed = outputspeed(cur_term);
#endif		NONSTANDARD
	if (outspeed <= 0 || outspeed >= (sizeof tmspc10 / sizeof tmspc10[0]))
		return ERR;

	mspc10 = tmspc10[outspeed];
	delay += mspc10 / 2;
	if (pad_char)
		pc = *pad_char;
	else
		pc = 0;
	for (delay /= mspc10; delay > 0; delay--)
		(*outc)(pc);
	return OK;
}