ed.c

Version 6 Unix 核心源代码 Version 6 Unix 核心源代码

#

/*
 * Editor
 */

#define	SIGHUP	1
#define	SIGINTR	2
#define	SIGQUIT	3
#define	FNSIZE	64
#define	LBSIZE	512
#define	ESIZE	128
#define	GBSIZE	256
#define	NBRA	5
#define	EOF	-1

#define	CBRA	1
#define	CCHR	2
#define	CDOT	4
#define	CCL	6
#define	NCCL	8
#define	CDOL	10
#define	CEOF	11
#define	CKET	12

#define	STAR	01

#define	error	goto errlab
#define	READ	0
#define	WRITE	1

int	peekc;
int	lastc;
char	savedfile[FNSIZE];
char	file[FNSIZE];
char	linebuf[LBSIZE];
char	rhsbuf[LBSIZE/2];
char	expbuf[ESIZE+4];
int	circfl;
int	*zero;
int	*dot;
int	*dol;
int	*endcore;
int	*fendcore;
int	*addr1;
int	*addr2;
char	genbuf[LBSIZE];
int	count[2];
char	*nextip;
char	*linebp;
int	ninbuf;
int	io;
int	pflag;
int	onhup;
int	onquit;
int	vflag	1;
int	listf;
int	col;
char	*globp;
int	tfile	-1;
int	tline;
char	*tfname;
char	*loc1;
char	*loc2;
char	*locs;
char	ibuff[512];
int	iblock	-1;
char	obuff[512];
int	oblock	-1;
int	ichanged;
int	nleft;
int	errfunc();
int	*errlab	errfunc;
char	TMPERR[] "TMP";
int	names[26];
char	*braslist[NBRA];
char	*braelist[NBRA];

main(argc, argv)
char **argv;
{
	register char *p1, *p2;
	extern int onintr();

	onquit = signal(SIGQUIT, 1);
	onhup = signal(SIGHUP, 1);
	argv++;
	if (argc > 1 && **argv=='-') {
		vflag = 0;
		/* allow debugging quits? */
		if ((*argv)[1]=='q') {
			signal(SIGQUIT, 0);
			vflag++;
		}
		argv++;
		argc--;
	}
	if (argc>1) {
		p1 = *argv;
		p2 = savedfile;
		while (*p2++ = *p1++);
		globp = "r";
	}
	fendcore = sbrk(0);
	init();
	if ((signal(SIGINTR, 1) & 01) == 0)
		signal(SIGINTR, onintr);
	setexit();
	commands();
	unlink(tfname);
}

commands()
{
	int getfile(), gettty();
	register *a1, c;
	register char *p;
	int r;

	for (;;) {
	if (pflag) {
		pflag = 0;
		addr1 = addr2 = dot;
		goto print;
	}
	addr1 = 0;
	addr2 = 0;
	do {
		addr1 = addr2;
		if ((a1 = address())==0) {
			c = getchar();
			break;
		}
		addr2 = a1;
		if ((c=getchar()) == ';') {
			c = ',';
			dot = a1;
		}
	} while (c==',');
	if (addr1==0)
		addr1 = addr2;
	switch(c) {

	case 'a':
		setdot();
		newline();
		append(gettty, addr2);
		continue;

	case 'c':
		delete();
		append(gettty, addr1-1);
		continue;

	case 'd':
		delete();
		continue;

	case 'e':
		setnoaddr();
		if ((peekc = getchar()) != ' ')
			error;
		savedfile[0] = 0;
		init();
		addr2 = zero;
		goto caseread;

	case 'f':
		setnoaddr();
		if ((c = getchar()) != '\n') {
			peekc = c;
			savedfile[0] = 0;
			filename();
		}
		puts(savedfile);
		continue;

	case 'g':
		global(1);
		continue;

	case 'i':
		setdot();
		nonzero();
		newline();
		append(gettty, addr2-1);
		continue;

	case 'k':
		if ((c = getchar()) < 'a' || c > 'z')
			error;
		newline();
		setdot();
		nonzero();
		names[c-'a'] = *addr2 | 01;
		continue;

	case 'm':
		move(0);
		continue;

	case '\n':
		if (addr2==0)
			addr2 = dot+1;
		addr1 = addr2;
		goto print;

	case 'l':
		listf++;
	case 'p':
		newline();
	print:
		setdot();
		nonzero();
		a1 = addr1;
		do
			puts(getline(*a1++));
		while (a1 <= addr2);
		dot = addr2;
		listf = 0;
		continue;

	case 'q':
		setnoaddr();
		newline();
		unlink(tfname);
		exit();

	case 'r':
	caseread:
		filename();
		if ((io = open(file, 0)) < 0) {
			lastc = '\n';
			error;
		}
		setall();
		ninbuf = 0;
		append(getfile, addr2);
		exfile();
		continue;

	case 's':
		setdot();
		nonzero();
		substitute(globp);
		continue;

	case 't':
		move(1);
		continue;

	case 'v':
		global(0);
		continue;

	case 'w':
		setall();
		nonzero();
		filename();
		if ((io = creat(file, 0666)) < 0)
			error;
		putfile();
		exfile();
		continue;

	case '=':
		setall();
		newline();
		count[1] = (addr2-zero)&077777;
		putd();
		putchar('\n');
		continue;

	case '!':
		unix();
		continue;

	case EOF:
		return;

	}
	error;
	}
}

address()
{
	register *a1, minus, c;
	int n, relerr;

	minus = 0;
	a1 = 0;
	for (;;) {
		c = getchar();
		if ('0'<=c && c<='9') {
			n = 0;
			do {
				n =* 10;
				n =+ c - '0';
			} while ((c = getchar())>='0' && c<='9');
			peekc = c;
			if (a1==0)
				a1 = zero;
			if (minus<0)
				n = -n;
			a1 =+ n;
			minus = 0;
			continue;
		}
		relerr = 0;
		if (a1 || minus)
			relerr++;
		switch(c) {
		case ' ':
		case '\t':
			continue;
	
		case '+':
			minus++;
			if (a1==0)
				a1 = dot;
			continue;

		case '-':
		case '^':
			minus--;
			if (a1==0)
				a1 = dot;
			continue;
	
		case '?':
		case '/':
			compile(c);
			a1 = dot;
			for (;;) {
				if (c=='/') {
					a1++;
					if (a1 > dol)
						a1 = zero;
				} else {
					a1--;
					if (a1 < zero)
						a1 = dol;
				}
				if (execute(0, a1))
					break;
				if (a1==dot)
					error;
			}
			break;
	
		case '$':
			a1 = dol;
			break;
	
		case '.':
			a1 = dot;
			break;

		case '\'':
			if ((c = getchar()) < 'a' || c > 'z')
				error;
			for (a1=zero; a1<=dol; a1++)
				if (names[c-'a'] == (*a1|01))
					break;
			break;
	
		default:
			peekc = c;
			if (a1==0)
				return(0);
			a1 =+ minus;
			if (a1<zero || a1>dol)
				error;
			return(a1);
		}
		if (relerr)
			error;
	}
}

setdot()
{
	if (addr2 == 0)
		addr1 = addr2 = dot;
	if (addr1 > addr2)
		error;
}

setall()
{
	if (addr2==0) {
		addr1 = zero+1;
		addr2 = dol;
		if (dol==zero)
			addr1 = zero;
	}
	setdot();
}

setnoaddr()
{
	if (addr2)
		error;
}

nonzero()
{
	if (addr1<=zero || addr2>dol)
		error;
}

newline()
{
	register c;

	if ((c = getchar()) == '\n')
		return;
	if (c=='p' || c=='l') {
		pflag++;
		if (c=='l')
			listf++;
		if (getchar() == '\n')
			return;
	}
	error;
}

filename()
{
	register char *p1, *p2;
	register c;

	count[1] = 0;
	c = getchar();
	if (c=='\n' || c==EOF) {
		p1 = savedfile;
		if (*p1==0)
			error;
		p2 = file;
		while (*p2++ = *p1++);
		return;
	}
	if (c!=' ')
		error;
	while ((c = getchar()) == ' ');
	if (c=='\n')
		error;
	p1 = file;
	do {
		*p1++ = c;
	} while ((c = getchar()) != '\n');
	*p1++ = 0;
	if (savedfile[0]==0) {
		p1 = savedfile;
		p2 = file;
		while (*p1++ = *p2++);
	}
}

exfile()
{
	close(io);
	io = -1;
	if (vflag) {
		putd();
		putchar('\n');
	}
}

onintr()
{
	signal(SIGINTR, onintr);
	putchar('\n');
	lastc = '\n';
	error;
}

errfunc()
{
	register c;

	listf = 0;
	puts("?");
	count[0] = 0;
	seek(0, 0, 2);
	pflag = 0;
	if (globp)
		lastc = '\n';
	globp = 0;
	peekc = lastc;
	while ((c = getchar()) != '\n' && c != EOF);
	if (io > 0) {
		close(io);
		io = -1;
	}
	reset();
}

getchar()
{
	if (lastc=peekc) {
		peekc = 0;
		return(lastc);
	}
	if (globp) {
		if ((lastc = *globp++) != 0)
			return(lastc);
		globp = 0;
		return(EOF);
	}
	if (read(0, &lastc, 1) <= 0)
		return(lastc = EOF);
	lastc =& 0177;
	return(lastc);
}

gettty()
{
	register c, gf;
	register char *p;

	p = linebuf;
	gf = globp;
	while ((c = getchar()) != '\n') {
		if (c==EOF) {
			if (gf)
				peekc = c;
			return(c);
		}
		if ((c =& 0177) == 0)
			continue;
		*p++ = c;
		if (p >= &linebuf[LBSIZE-2])
			error;
	}
	*p++ = 0;
	if (linebuf[0]=='.' && linebuf[1]==0)
		return(EOF);
	return(0);
}

getfile()
{
	register c;
	register char *lp, *fp;

	lp = linebuf;
	fp = nextip;
	do {
		if (--ninbuf < 0) {
			if ((ninbuf = read(io, genbuf, LBSIZE)-1) < 0)
				return(EOF);
			fp = genbuf;
		}
		if (lp >= &linebuf[LBSIZE])
			error;
		if ((*lp++ = c = *fp++ & 0177) == 0) {
			lp--;
			continue;
		}
		if (++count[1] == 0)
			++count[0];
	} while (c != '\n');
	*--lp = 0;
	nextip = fp;
	return(0);
}

putfile()
{
	int *a1;
	register char *fp, *lp;
	register nib;

	nib = 512;
	fp = genbuf;
	a1 = addr1;
	do {
		lp = getline(*a1++);
		for (;;) {
			if (--nib < 0) {
				write(io, genbuf, fp-genbuf);
				nib = 511;
				fp = genbuf;
			}
			if (++count[1] == 0)
				++count[0];
			if ((*fp++ = *lp++) == 0) {
				fp[-1] = '\n';
				break;
			}
		}
	} while (a1 <= addr2);
	write(io, genbuf, fp-genbuf);
}

append(f, a)
int (*f)();
{
	register *a1, *a2, *rdot;
	int nline, tl;
	struct { int integer; };

	nline = 0;
	dot = a;
	while ((*f)() == 0) {
		if (dol >= endcore) {
			if (sbrk(1024) == -1)
				error;
			endcore.integer =+ 1024;
		}
		tl = putline();
		nline++;
		a1 = ++dol;
		a2 = a1+1;
		rdot = ++dot;
		while (a1 > rdot)
			*--a2 = *--a1;
		*rdot = tl;
	}
	return(nline);
}

unix()
{
	register savint, pid, rpid;
	int retcode;

	setnoaddr();
	if ((pid = fork()) == 0) {
		signal(SIGHUP, onhup);
		signal(SIGQUIT, onquit);
		execl("/bin/sh", "sh", "-t", 0);
		exit();
	}
	savint = signal(SIGINTR, 1);
	while ((rpid = wait(&retcode)) != pid && rpid != -1);
	signal(SIGINTR, savint);
	puts("!");
}

delete()
{
	register *a1, *a2, *a3;

	setdot();
	newline();
	nonzero();
	a1 = addr1;
	a2 = addr2+1;
	a3 = dol;
	dol =- a2 - a1;
	do
		*a1++ = *a2++;
	while (a2 <= a3);
	a1 = addr1;
	if (a1 > dol)
		a1 = dol;
	dot = a1;
}

getline(tl)
{
	register char *bp, *lp;
	register nl;