vt.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

					/*
					 * h - set various options.
					 */
					case 'h':
						if(noperand == 1){
							switch(operand[0]){
							default:
								break;
							case 20:	/* set newline mode */
								ttystate[cs->raw].nlcr = 0;
								break;
							case 30:	/* screen visible (? not supported through VT220) */
								break;
							}
						}else while(--noperand > 0){
							switch(operand[noperand]){
							default:
								break;
							case 1:	/* set cursor keys to send application function: ESC O A..D */
								break;
							case 2:	/* set ANSI */
								break;
							case 3:	/* set 132 columns */
								setdim(-1, 132);
								break;
							case 4:	/* set smooth scrolling */
								break;
							case 5:	/* set screen to reverse video (not implemented) */
								break;
							case 6:	/* set origin to relative */
								originrelative = 1;
								x = 0;
								y = yscrmin;
								break;
							case 7:	/* set auto-wrap mode */
								wraparound = 1;
								break;
							case 8:	/* set auto-repeat mode */
								break;
							case 9:	/* set interlacing mode */
								break;
							case 25:	/* text cursor on (VT220) */
								cursoron = 1;
								break;
							}
						}
						break;

					/*
					 * m - change character attrs.
					 */
					case 'm':
						setattr(noperand, operand);
						break;

					/*
					 * n - request various reports
					 */
					case 'n':
						switch(operand[0]){
						case 5:	/* status */
							sendnchars2(4, "\033[0n");	/* terminal ok */
							break;
						case 6:	/* cursor position */
							sendnchars2(sprint(buf, "\033[%d;%dR",
								originrelative ? y+1 - yscrmin : y+1, x+1), buf);
							break;
						}
						break;

					/*
					 * q - turn on list of LEDs; turn off others.
					 */
					case 'q':
						break;

					/*
					 * r - change scrolling region.  operand[0] is
					 * min scrolling region and operand[1] is max
					 * scrolling region.
					 */
					case 'r':
						yscrmin = 0;
						yscrmax = ymax;
						switch(noperand){
						case 2:
							yscrmax = operand[1]-1;
							if(yscrmax > ymax)
								yscrmax = ymax;
						case 1:
							yscrmin = operand[0]-1;
							if(yscrmin < 0)
								yscrmin = 0;
						}
						x = 0;
						y = yscrmin;
						break;

					/*
					 * x - report terminal parameters
					 */
					case 'x':
						sendnchars2(20, "\033[3;1;1;120;120;1;0x");
						break;

					/*
					 * y - invoke confidence test
					 */
					case 'y':
						break;

					/*
					 * A - cursor up.
					 */
					case 'e':
					case 'A':
						fixops(operand);
						y -= operand[0];
						if(y < yscrmin)
							y = yscrmin;
						olines -= operand[0];
						if(olines < 0)
							olines = 0;
						break;

					/*
					 * B - cursor down
					 */
					case 'B':
						fixops(operand);
						y += operand[0];
						if(y > yscrmax)
							y=yscrmax;
						break;
					
					/*
					 * C - cursor right
					 */
					case 'a':
					case 'C':
						fixops(operand);
						x += operand[0];
						/*
						 * VT-100-UG says not to go past the
						 * right margin.
						 */
						if(x > xmax)
							x = xmax;
						break;

					/*
					 * D - cursor left
					 */
					case 'D':
						fixops(operand);
						x -= operand[0];
						if(x < 0)
							x = 0;
						break;

					/*
					 *	G - cursor to column
					 */
					case '\'':
					case 'G':
						fixops(operand);
						x = operand[0] - 1;
						if(x > xmax)
							x = xmax;
						break;

					/*
					 * H and f - cursor motion.  operand[0] is row and
					 * operand[1] is column, origin 1.
					 */
					case 'H':
					case 'f':
						fixops(operand+1);
						x = operand[1] - 1;
						if(x > xmax)
							x = xmax;

						/* fallthrough */

					/*
					 * d - cursor to line n (xterm)
					 */
					case 'd':
						fixops(operand);
						y = operand[0] - 1;
						if(originrelative){
							y += yscrmin;
							if(y > yscrmax)
								y = yscrmax;
						}else{
							if(y > ymax)
								y = ymax;
						}
						break;

					/*
					 * J - clear some or all of the display.
					 */
					case 'J':
						switch (operand[0]) {
							/*
							 * operand 2:  whole screen.
							 */
							case 2:
								clear(Rpt(pt(0, 0), pt(xmax+1, ymax+1)));
								break;
							/*
							 * operand 1: start of screen to active position, inclusive.
							 */
							case 1:
								clear(Rpt(pt(0, 0), pt(xmax+1, y)));
								clear(Rpt(pt(0, y), pt(x+1, y+1)));
								break;
							/*
							 * Default:  active position to end of screen, inclusive.
							 */
							default:
								clear(Rpt(pt(x, y), pt(xmax+1, y+1)));
								clear(Rpt(pt(0, y+1), pt(xmax+1, ymax+1)));
								break;
						}
						break;

					/*
					 * K - clear some or all of the line.
					 */
					case 'K':
						switch (operand[0]) {
							/*
							 * operand 2: whole line.
							 */
							case 2:
								clear(Rpt(pt(0, y), pt(xmax+1, y+1)));
								break;
							/*
							 * operand 1: start of line to active position, inclusive.
							 */
							case 1:
								clear(Rpt(pt(0, y), pt(x+1, y+1)));
								break;
							/*
							 * Default: active position to end of line, inclusive.
							 */
							default:
								clear(Rpt(pt(x, y), pt(xmax+1, y+1)));
								break;
						}
						break;

					/*
					 *	P - delete character(s) from right of cursor (xterm)
					 */
					case 'P':
						fixops(operand);
						i = x + operand[0];
						draw(screen, Rpt(pt(x, y), pt(xmax+1, y+1)), screen, nil, pt(i, y));
						clear(Rpt(pt(xmax-operand[0], y), pt(xmax+1, y+1)));
						break;

					/*
					 *	@ - insert blank(s) to right of cursor (xterm)
					 */
					case '@':
						fixops(operand);
						i = x + operand[0];
						draw(screen, Rpt(pt(i, y), pt(xmax+1, y+1)), screen, nil, pt(x, y));
						clear(Rpt(pt(x, y), pt(i, y+1)));
						break;


					/*
					 *	X - erase character(s) at cursor and to the right (xterm)
					 */
					case 'X':
						fixops(operand);
						i = x + operand[0];
						clear(Rpt(pt(x, y), pt(i, y+1)));
						break;

					/*
					 * L - insert a line at cursor position (VT102 and later)
					 */
					case 'L':
						fixops(operand);
						for(i = 0; i < operand[0]; ++i)
							scroll(y, yscrmax, y+1, y);
						break;

					/*
					 * M - delete a line at cursor position (VT102 and later)
					 */
					case 'M':
						fixops(operand);
						for(i = 0; i < operand[0]; ++i)
							scroll(y+1, yscrmax+1, y, yscrmax);
						break;

					/*
					 * S,T - scroll up/down (xterm)
					 */
					case 'T':
						fixops(operand);
						for(i = 0; i < operand[0]; ++i)
							scroll(yscrmin, yscrmax, yscrmin+1, yscrmin);
						break;

					case 'S':
						fixops(operand);
						for(i = 0; i < operand[0]; ++i)
							scroll(yscrmin+1, yscrmax+1, yscrmin, yscrmin);
						break;

					case '=':	/* ? not supported through VT220 */
						number(buf, nil);
						switch(buf[0]) {
						case 'h':
						case 'l':
							break;
						}
						break;

					/*
					 * Anything else we ignore for now...
					 */
					default:
print("unknown escape2 '%c' (0x%x)\n", dch, dch);
						break;
				}

				break;

			/*
			 * Collapse multiple '\033' to one.
			 */
			case '\033':
				peekc = '\033';
				break;

			/* set title */
			case ']':	/* it's actually <esc> ] num ; title <bel> */
				{
					int ch, fd;
					number(buf, nil);
					i = 0;
					while((ch = get_next_char()) != '\a')
						if(i < sizeof buf)
							buf[i++] = ch;
					fd = open("/dev/label", OWRITE);
					write(fd, buf, i);
					close(fd);
				}
				break;

			/*
			 * Ignore other commands.
			 */
			default:
print("unknown command '%c' (0x%x)\n", dch, dch);
				break;

			}
			break;

		default:		/* ordinary char */
Default:
			if(isgraphics && gmap[(uchar) buf[0]])
				buf[0] = gmap[(uchar) buf[0]];

			/* line wrap */
			if (x > xmax){
				if(wraparound){
					x = 0;
					newline();
				}else{
					continue;
				}
			}
			n = 1;
			c = 0;
			while (!cs->raw && host_avail() && x+n<=xmax && n<BUFS
			    && (c = get_next_char())>=' ' && c<'\177') {
				buf[n++] = c;
				c = 0;
			}
			buf[n] = 0;
//			clear(Rpt(pt(x,y), pt(x+n, y+1)));
			drawstring(pt(x, y), buf, attr);
			x += n;
			peekc = c;
			break;
		}
	}
}

static void
setattr(int argc, int *argv)
{
	int i;

	for(i=0; i<argc; i++) {
		switch(argv[i]) {
		case 0:
			attr = defattr;
			fgcolor = fgdefault;
			bgcolor = bgdefault;
			break;
		case 1:
			attr |= THighIntensity;
			break;		
		case 4:
			attr |= TUnderline;
			break;		
		case 5:
			attr |= TBlink;
			break;
		case 7:
			attr |= TReverse;
			break;
		case 8:
			attr |= TInvisible;
			break;
		case 22:
			attr &= ~THighIntensity;
			break;		
		case 24:
			attr &= ~TUnderline;
			break;		
		case 25:
			attr &= ~TBlink;
			break;
		case 27:
			attr &= ~TReverse;
			break;
		case 28:
			attr &= ~TInvisible;
			break;
		case 30:	/* black */
		case 31:	/* red */
		case 32:	/* green */
		case 33:	/* brown */
		case 34:	/* blue */
		case 35:	/* purple */
		case 36:	/* cyan */
		case 37:	/* white */
			fgcolor = colors[argv[i]-30];
			break;
		case 39:
			fgcolor = fgdefault;
			break;
		case 40:	/* black */
		case 41:	/* red */
		case 42:	/* green */
		case 43:	/* brown */
		case 44:	/* blue */
		case 45:	/* purple */
		case 46:	/* cyan */
		case 47:	/* white */
			bgcolor = colors[argv[i]-40];
			break;
		case 49:
			bgcolor = bgdefault;
			break;
		}
	}
}