mterm.c

c语言的小编译器,学习的好东东.

			xy_flag = -1;
			if(c == 0x1B) {				/* Begin escape sequence */
				state = 1;
				parms[0] = parms[1] = value = parm = 0; }
			else switch(state) {
				case 1 :				/* Escape already received */
					if(c == '[') {
						state = 2;
						break; }
					state = 0;
				case 0 :				/* No special processing */
					vputc(c);
					break;
				case 2 :				/* Waiting for numeric parms */
					if(isdigit(c)) {
						value = (value * 10) + (c - '0');
						break; }
					parms[parm++] = value;	/* More to come */
					if(c == ';') {
						value = 0;
						break; }
					state = 0;
					switch(c) {
						case 'H' :		/* Cursor position (1) */
						case 'f' :		/* Cursor position (2) */
							if(y = parms[0])
								--y;
							if(x = parms[1])
								--x;
							vgotoxy(x, y);
							break;
						case 'J' :		/* Erase in display */
							x = V_XY;
							value ? vclscr() : vcleos();
							V_XY = x;
							break;
						case 'K' :		/* Erase in line */
							x = V_XY;
							if(value)
								V_XY &= 0xff00;
							vcleol();
							V_XY = x;
							break;
						case 'm' :		/* Select attributes */
							x = 0;
							do {
								V_ATTR  = (y = parms[x]) ? (y == 4) ?
									UNDERLINE : REVERSE : NORMAL; }
							while(++x < parm); } } }
		else if(xy_flag) {				/* Cursor has moved */
			vupdatexy();
			xy_flag = 0; }

		/* Process any input from the keyboard */
		if(c = vtstc()) {
			if(c & 0x80) {				/* Special function key */
				if(!(ptr = ansi_keys[c & 0x7f]))
					return;
				while(*ptr)
					Cputc(*ptr++); }
			else
				Cputc((c == '\n') ? '\r' : c); } }
}

/*
 * Receive a file in XMODEM protocol
 */
download()
{
	char rbuffer[BLOCK_SIZE], *error_text, *old_error, ochr;
	int r, rx_block_num, error_count;
	FILE *fp;

	if(vgets(FILCOL,MSGROW,"Write to file? ",dfile,FILSIZ) || !*dfile)
		return;

	if(!(fp = openf(dfile, -1)))
		return;

	info_box("Download to file", dfile);

	error_text = old_error = rx_block_num = 1;
	error_count = RETRYS;
	do {
		if(vtstc() == 0x1b) {		/* Console escape */
			ochr = CAN;
			error_text = "CANCELED";
			error_count = 0; }
		else if((r = get_record(rbuffer)) == (rx_block_num & 255)) {
			error_count = RETRYS;
			fput(rbuffer, BLOCK_SIZE, fp);
			vgotoxy(SUBCOL+23, MENROW+5);
			vprintf("%u", rx_block_num++);
			error_text = "RX PACKET";
			ochr = ACK; }
		else {
			switch(r) {
				case -1 :		/* Timeout */
					error_text = "TIMEOUT";
					ochr = NAK;
					break;
				case -2 :		/* Bad block */
					error_text = "BAD BLOCK#";
					while(Cgett(RX_TIMEOUT) != -1);
					ochr = NAK;
					break;
				case -3 :		/* Bad checksum */
					error_text = "BAD CHKSUM";
					ochr = NAK;
					break;
				case -4 :		/* End of file */
					error_text = "DONE";
					ochr = ACK;
					break;
				case -5 :		/* Cancel */
					error_text = "ABORTED";
					ochr = ACK;
					break;
				default:		/* Block out of sequence */
					error_text = "WRONG BLK";
					ochr = NAK; }
				--error_count; }
			Cputc(ochr);
			/* Update status message */
			if(error_text != old_error)
				transfer_status(old_error = error_text); }
		while((r > -3) && error_count);

	message("Download ended (Press ENTER)");
	fclose(fp);
	while(vgetc() != '\n');
	vclear_box(SUBCOL, MENROW+1, 50, 8);
}

/*
 * Read a record in the XMODEM protocol, return the block number
 * (0-255) if successful, or one of the following return codes:
 *	-1 = Timeout
 *	-2 = Bad block number
 *	-3 = Bad block checksum
 *	-4 = End of file
 *	-5 = Canceled by remote
 */
get_record(rbuffer)
	char rbuffer[];
{
	int c, i, block_num, check_sum;

	check_sum = 0;
	i = -2;
	switch(Cgett(SOH_TIMEOUT)) {
		case SOH :		/* Receive packet */
			for(;;) {
				if((c = Cgett(RX_TIMEOUT)) == -1)	/* receive timeout */
					break;
				if(i == -2)							/* first block number */
					block_num = c;
				else if(i == -1) {					/* second block number */
					if((255 & ~c) != block_num)
						return -2; }
				else if(i == BLOCK_SIZE)			/* checksum at end */
					return (check_sum & 0xff) == c ? block_num : -3;
				else								/* data character */
					check_sum += (rbuffer[i] = c);
				++i; }
		case -1 :		/* timeout on waiting for packet */
			return -1;
		case EOT :		/* end of file encountered */
			return -4;
		case CAN :		/* cancel protocol */
			return -5; }
}

/*
 * Transmit a file in XMODEM protocol
 */
upload()
{
	int i, c, tx_block_num, error_count;
	char buffer[BLOCK_SIZE], *error_text, *old_error;
	FILE *fp;

	if(vgets(FILCOL,MSGROW,"Read from file? ",ufile,FILSIZ) || !*ufile)
		return;

	if(!(fp = openf(ufile, 0)))
		return;

	info_box("Upload from file", ufile);

	tx_block_num = old_error = error_text = 1;
	error_count = RETRYS;

	/* Transmit the file data */
	while(i = fget(buffer, BLOCK_SIZE, fp)) {
		while(i < 128)
				buffer[i++] = -1;
		error_text = "TX PACKET";
		while(i = send_record(buffer, tx_block_num)) {
			switch(i) {
				case -1 :
					error_text = "TIMEOUT";
					break;
				case -3 :
					error_text = "RECV NAK";
					break;
				case -5 :
					error_text = "ABORTED"; }
				transfer_status(old_error = error_text);
				if((i < -3) || !error_count--)
					break; }
		if(vtstc() == 0x1b) {		/* Console escape */
			i = -5;
			error_text = "CANCELED"; }
		if(i) {						/* Error exit */
			Cputc(CAN);
			break; }
		error_count = RETRYS;
		vgotoxy(SUBCOL+23, MENROW+5);
		vprintf("%u", tx_block_num++);
		if(error_text != old_error)
			transfer_status(old_error = error_text); }

	/* Send the end of file indicator */
	error_count = RETRYS;
	if(!i) for(;;) {
		Cputc(EOT);
		if((c = Cgett(ACK_TIMEOUT)) == ACK) {
			error_text = "DONE";
			break; }
		if(c == CAN) {
			error_text = "ABORTED";
			break; }
		if(((c == -1) || (c == NAK)) && !error_count--) {
			error_text = "TIMEOUT";
			break; } }

	transfer_status(error_text);
	message("Upload ended (Press ENTER)");
	fclose(fp);
	while(vgetc() != '\n');
	vclear_box(SUBCOL, MENROW+1, 50, 8);
}

/*
 * Send an record in XMODEM protocol, return 0 if successful
 * Otherwise, return one of the following:
 *	-1 = Timeout
 *	-2 = Bad block number	(N/A)
 *	-3 = Bad block			(NAK RECEIVED)
 *	-4 = End of file		(N/A)
 *	-5 = Canceled by remote
 */
send_record(buffer, block_num)
	char *buffer;
	int block_num;
{
	int i, check_sum;
	char *ptr;

	check_sum = 0;
	ptr = buffer;
	while(Ctestc() != -1);		/* purge any received data */
	Cputc(SOH);
	Cputc(block_num);
	Cputc(~block_num);
	for(i=0; i < BLOCK_SIZE; ++i) {
		Cputc(*buffer);
		check_sum += *buffer++; }
	Cputc(check_sum);

	for(;;) switch(Cgett(ACK_TIMEOUT)) {
		case ACK :			/* Packet received ok */
			return 0;
		case NAK :			/* Rejected */
			return -3;
		case CAN :			/* Remote cancel */
			return -5;
		case -1 :			/* Timeout */
			return -1; }
}

/*
 * Wait for a character from the modem (with timeout)
 */
Cgett(timeout)
	unsigned timeout;
{
	int h, m, s, old_s;

	if((h = Ctestc()) != -1)	/* Very fast if characters buffered */
		return h;

	get_time(&h, &m, &old_s);
	do {
		do {
			if((h = Ctestc()) != -1)
				return h;
			get_time(&h,&m,&s); }
		while(s == old_s);
		old_s = s; }
	while(--timeout);
	return -1;
}

/*
 * Main program, either TSR or execute main tty program menu
 */
main(argc, argv)
	int argc;
	int *argv[];
{
	vopen();
	vputs("MICRO-Terminal: (Press CTRL-HOME or CTRL-END to exit):\n");
	save_screen();

/* If RAM-resident, print startup message & TSR */
	if((argc > 1) && (*argv[1] == 't-')) {
		draw_title();
		printf("\n\n\nRam-Resident MICRO-Terminal installed\nPress BOTH SHIFTS to POP UP\n");
		vcursor_line();
		tsr(&tty_main, L_SHIFT+R_SHIFT, 2000); }

/* Not RAM-resident, execute the program */
	vclscr();		/* Return to blank screen */
	tty_main();
}