tk.c

unix v7是最后一个广泛发布的研究型UNIX版本

/*
 * optimize output for Tek 4014
 */

#include <stdio.h>
#include <signal.h>

#define MAXY 3071
#define LINE 47
#define XOFF 248
#define US 037
#define GS 035
#define ESC 033
#define CR 015
#define FF 014
#define SO 016
#define SI 017

int	pl	= 66*LINE;
int	yyll	= -1;
char	obuf[BUFSIZ];
int	xx = XOFF;
int	xoff = XOFF;
int	coff = 0;
int	ncol = 0;
int	maxcol = 1;
int	yy = MAXY;
int	ohy = -1;
int	ohx = -1;
int	oxb = -1;
int	oly = -1;
int	olx = -1;
int	alpha;
int	ry;
FILE	*ttyin;

main(argc, argv)
int argc;
char **argv;
{
	register i, j;
	extern ex();

	while (--argc > 0 && (++argv)[0][0]=='-')
		switch(argv[0][1]) {
			case 'p':
				if (i = atoi(&argv[0][2]))
					pl = i;
					yyll = MAXY + 1 - pl;
				break;
			default:
				if (i = atoi(&argv[0][1])) {
					maxcol = i;
					xx = xoff = 0;
					coff = 4096/i;
				}
				break;
		}
	if ((ttyin = fopen("/dev/tty", "r")) != NULL)
		setbuf(ttyin, (char *)NULL);
	if (argc) {
		if (freopen(argv[0], "r", stdin) == NULL) {
			fprintf(stderr, "tk: cannot open %s\n", argv[0]);
			exit(1);
		}
	}
	signal(SIGINT, ex);
	setbuf(stdout, obuf);
	ncol = maxcol;
	init();
	while ((i = getchar()) != EOF) {
		switch(i) {

		case FF:
			yy = 0;
		case '\n':
			xx = xoff;
			yy -= LINE;
			alpha = 0;
			if (yy < yyll) {
				ncol++;
				yy = 0;
				sendpt(0);
				putchar(US);
				fflush(stdout);
				if (ncol >= maxcol)
					kwait();
				init();
			}
			continue;

		case CR:
			xx = xoff;
			alpha = 0;
			continue;

		case ' ':
			xx += 31;
			alpha = 0;
			continue;

		case '\t': /*tabstops at 8*31=248*/
			j = ((xx-xoff)/248) + 1;
			xx += j*248 - (xx-xoff);
			alpha = 0;
			continue;

		case '\b':
			xx -= 31;
			alpha = 0;
			continue;

		case ESC:
			switch(i = getchar()) {
			case '7':
				yy += LINE;
				alpha = 0;
				continue;
			case '8':
				yy += (LINE + ry)/2;
				ry = (LINE + ry)%2;
				alpha = 0;
				continue;
			case '9':
				yy -= (LINE - ry)/2;
				ry = -(LINE - ry)%2;
				alpha = 0;
				continue;
			default:
				continue;
			}

		default:
			sendpt(alpha);
			if (alpha==0) {
				putchar(US);
				alpha = 1;
			}
			putchar(i);
			if (i>' ')
				xx += 31;
			continue;
		}
	}
	xx = xoff;
	yy = 0;
	sendpt(0);
	putchar(US);
	kwait();
	ex();
}

init()
{
	ohx = oxb = olx = ohy = oly = -1;
	if (ncol >= maxcol) {
		ncol = 0;
		if (maxcol > 1)
			xoff = 0;
		else
			xoff = XOFF;
	} else
		xoff += coff;
	xx = xoff;
	yy = MAXY;
	if (ncol==0)
		fputs("\033\014\033;", stdout);
	sendpt(0);
}

ex()
{
	yy = MAXY;
	xx = 0;
	fputs("\033;\037", stdout);
	sendpt(1);
	exit(0);
}

kwait()
{
	register c;

	fflush(stdout);
	if (ttyin==NULL)
		return;
	while ((c=getc(ttyin))!='\n') {
		if (c=='!') {
			execom();
			printf("!\n");
			fflush(stdout);
			continue;
		}
		if (c==EOF)
			ex();
	}
}

execom()
{
	int (*si)(), (*sq)();

	if (fork() != 0) {
		si = signal(SIGINT, SIG_IGN);
		sq = signal(SIGQUIT, SIG_IGN);
		wait((int *)NULL);
		signal(SIGINT, si);
		signal(SIGQUIT, sq);
		return;
	}
	if (isatty(fileno(stdin)) == 0) {
		if (freopen("/dev/tty", "r", stdin)==NULL)
			freopen("/dev/null", "r", stdin);
	}
	execl("/bin/sh", "sh", "-t", 0);
}

sendpt(a)
{
	register zz;
	int hy,xb,ly,hx,lx;

	if (a)
		return;
	if ((zz = yy) < 0)
		zz = 0;
	hy = ((zz>>7) & 037);
	xb = ((xx & 03) + ((zz<<2) & 014) & 017);
	ly = ((zz>>2) & 037);
	hx = ((xx>>7) & 037);
	lx = ((xx>>2) & 037);
	putchar(GS);
	if (hy != ohy)
		putchar(hy | 040);
	if (xb != oxb)
		putchar(xb | 0140);
	if ((ly != oly) || (hx != ohx) || (xb != oxb))
		putchar(ly | 0140);
	if (hx != ohx)
		putchar(hx | 040);
	putchar(lx | 0100);
	ohy = hy;
	oxb = xb;
	oly = ly;
	ohx = hx;
	olx = lx;
	alpha = 0;
}