ed.c

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

	lp = linebuf;
	bp = getblock(tl, READ);
	nl = nleft;
	tl =& ~0377;
	while (*lp++ = *bp++)
		if (--nl == 0) {
			bp = getblock(tl=+0400, READ);
			nl = nleft;
		}
	return(linebuf);
}

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

	lp = linebuf;
	tl = tline;
	bp = getblock(tl, WRITE);
	nl = nleft;
	tl =& ~0377;
	while (*bp = *lp++) {
		if (*bp++ == '\n') {
			*--bp = 0;
			linebp = lp;
			break;
		}
		if (--nl == 0) {
			bp = getblock(tl=+0400, WRITE);
			nl = nleft;
		}
	}
	nl = tline;
	tline =+ (((lp-linebuf)+03)>>1)&077776;
	return(nl);
}

getblock(atl, iof)
{
	extern read(), write();
	register bno, off;
	
	bno = (atl>>8)&0377;
	off = (atl<<1)&0774;
	if (bno >= 255) {
		puts(TMPERR);
		error;
	}
	nleft = 512 - off;
	if (bno==iblock) {
		ichanged =| iof;
		return(ibuff+off);
	}
	if (bno==oblock)
		return(obuff+off);
	if (iof==READ) {
		if (ichanged)
			blkio(iblock, ibuff, write);
		ichanged = 0;
		iblock = bno;
		blkio(bno, ibuff, read);
		return(ibuff+off);
	}
	if (oblock>=0)
		blkio(oblock, obuff, write);
	oblock = bno;
	return(obuff+off);
}

blkio(b, buf, iofcn)
int (*iofcn)();
{
	seek(tfile, b, 3);
	if ((*iofcn)(tfile, buf, 512) != 512) {
		puts(TMPERR);
		error;
	}
}

init()
{
	register char *p;
	register pid;

	close(tfile);
	tline = 0;
	iblock = -1;
	oblock = -1;
	tfname = "/tmp/exxxxx";
	ichanged = 0;
	pid = getpid();
	for (p = &tfname[11]; p > &tfname[6];) {
		*--p = (pid&07) + '0';
		pid =>> 3;
	}
	close(creat(tfname, 0600));
	tfile = open(tfname, 2);
	brk(fendcore);
	dot = zero = dol = fendcore;
	endcore = fendcore - 2;
}

global(k)
{
	register char *gp;
	register c;
	register int *a1;
	char globuf[GBSIZE];

	if (globp)
		error;
	setall();
	nonzero();
	if ((c=getchar())=='\n')
		error;
	compile(c);
	gp = globuf;
	while ((c = getchar()) != '\n') {
		if (c==EOF)
			error;
		if (c=='\\') {
			c = getchar();
			if (c!='\n')
				*gp++ = '\\';
		}
		*gp++ = c;
		if (gp >= &globuf[GBSIZE-2])
			error;
	}
	*gp++ = '\n';
	*gp++ = 0;
	for (a1=zero; a1<=dol; a1++) {
		*a1 =& ~01;
		if (a1>=addr1 && a1<=addr2 && execute(0, a1)==k)
			*a1 =| 01;
	}
	for (a1=zero; a1<=dol; a1++) {
		if (*a1 & 01) {
			*a1 =& ~01;
			dot = a1;
			globp = globuf;
			commands();
			a1 = zero;
		}
	}
}

substitute(inglob)
{
	register gsubf, *a1, nl;
	int getsub();

	gsubf = compsub();
	for (a1 = addr1; a1 <= addr2; a1++) {
		if (execute(0, a1)==0)
			continue;
		inglob =| 01;
		dosub();
		if (gsubf) {
			while (*loc2) {
				if (execute(1)==0)
					break;
				dosub();
			}
		}
		*a1 = putline();
		nl = append(getsub, a1);
		a1 =+ nl;
		addr2 =+ nl;
	}
	if (inglob==0)
		error;
}

compsub()
{
	register seof, c;
	register char *p;
	int gsubf;

	if ((seof = getchar()) == '\n')
		error;
	compile(seof);
	p = rhsbuf;
	for (;;) {
		c = getchar();
		if (c=='\\')
			c = getchar() | 0200;
		if (c=='\n')
			error;
		if (c==seof)
			break;
		*p++ = c;
		if (p >= &rhsbuf[LBSIZE/2])
			error;
	}
	*p++ = 0;
	if ((peekc = getchar()) == 'g') {
		peekc = 0;
		newline();
		return(1);
	}
	newline();
	return(0);
}

getsub()
{
	register char *p1, *p2;

	p1 = linebuf;
	if ((p2 = linebp) == 0)
		return(EOF);
	while (*p1++ = *p2++);
	linebp = 0;
	return(0);
}

dosub()
{
	register char *lp, *sp, *rp;
	int c;

	lp = linebuf;
	sp = genbuf;
	rp = rhsbuf;
	while (lp < loc1)
		*sp++ = *lp++;
	while (c = *rp++) {
		if (c=='&') {
			sp = place(sp, loc1, loc2);
			continue;
		} else if (c<0 && (c =& 0177) >='1' && c < NBRA+'1') {
			sp = place(sp, braslist[c-'1'], braelist[c-'1']);
			continue;
		}
		*sp++ = c&0177;
		if (sp >= &genbuf[LBSIZE])
			error;
	}
	lp = loc2;
	loc2 = sp + linebuf - genbuf;
	while (*sp++ = *lp++)
		if (sp >= &genbuf[LBSIZE])
			error;
	lp = linebuf;
	sp = genbuf;
	while (*lp++ = *sp++);
}

place(asp, al1, al2)
{
	register char *sp, *l1, *l2;

	sp = asp;
	l1 = al1;
	l2 = al2;
	while (l1 < l2) {
		*sp++ = *l1++;
		if (sp >= &genbuf[LBSIZE])
			error;
	}
	return(sp);
}

move(cflag)
{
	register int *adt, *ad1, *ad2;
	int getcopy();

	setdot();
	nonzero();
	if ((adt = address())==0)
		error;
	newline();
	ad1 = addr1;
	ad2 = addr2;
	if (cflag) {
		ad1 = dol;
		append(getcopy, ad1++);
		ad2 = dol;
	}
	ad2++;
	if (adt<ad1) {
		dot = adt + (ad2-ad1);
		if ((++adt)==ad1)
			return;
		reverse(adt, ad1);
		reverse(ad1, ad2);
		reverse(adt, ad2);
	} else if (adt >= ad2) {
		dot = adt++;
		reverse(ad1, ad2);
		reverse(ad2, adt);
		reverse(ad1, adt);
	} else
		error;
}

reverse(aa1, aa2)
{
	register int *a1, *a2, t;

	a1 = aa1;
	a2 = aa2;
	for (;;) {
		t = *--a2;
		if (a2 <= a1)
			return;
		*a2 = *a1;
		*a1++ = t;
	}
}

getcopy()
{
	if (addr1 > addr2)
		return(EOF);
	getline(*addr1++);
	return(0);
}

compile(aeof)
{
	register eof, c;
	register char *ep;
	char *lastep;
	char bracket[NBRA], *bracketp;
	int nbra;
	int cclcnt;

	ep = expbuf;
	eof = aeof;
	bracketp = bracket;
	nbra = 0;
	if ((c = getchar()) == eof) {
		if (*ep==0)
			error;
		return;
	}
	circfl = 0;
	if (c=='^') {
		c = getchar();
		circfl++;
	}
	if (c=='*')
		goto cerror;
	peekc = c;
	for (;;) {
		if (ep >= &expbuf[ESIZE])
			goto cerror;
		c = getchar();
		if (c==eof) {
			*ep++ = CEOF;
			return;
		}
		if (c!='*')
			lastep = ep;
		switch (c) {

		case '\\':
			if ((c = getchar())=='(') {
				if (nbra >= NBRA)
					goto cerror;
				*bracketp++ = nbra;
				*ep++ = CBRA;
				*ep++ = nbra++;
				continue;
			}
			if (c == ')') {
				if (bracketp <= bracket)
					goto cerror;
				*ep++ = CKET;
				*ep++ = *--bracketp;
				continue;
			}
			*ep++ = CCHR;
			if (c=='\n')
				goto cerror;
			*ep++ = c;
			continue;

		case '.':
			*ep++ = CDOT;
			continue;

		case '\n':
			goto cerror;

		case '*':
			if (*lastep==CBRA || *lastep==CKET)
				error;
			*lastep =| STAR;
			continue;

		case '$':
			if ((peekc=getchar()) != eof)
				goto defchar;
			*ep++ = CDOL;
			continue;

		case '[':
			*ep++ = CCL;
			*ep++ = 0;
			cclcnt = 1;
			if ((c=getchar()) == '^') {
				c = getchar();
				ep[-2] = NCCL;
			}
			do {
				if (c=='\n')
					goto cerror;
				*ep++ = c;
				cclcnt++;
				if (ep >= &expbuf[ESIZE])
					goto cerror;
			} while ((c = getchar()) != ']');
			lastep[1] = cclcnt;
			continue;

		defchar:
		default:
			*ep++ = CCHR;
			*ep++ = c;
		}
	}
   cerror:
	expbuf[0] = 0;
	error;
}

execute(gf, addr)
int *addr;
{
	register char *p1, *p2, c;

	if (gf) {
		if (circfl)
			return(0);
		p1 = linebuf;
		p2 = genbuf;
		while (*p1++ = *p2++);
		locs = p1 = loc2;
	} else {
		if (addr==zero)
			return(0);
		p1 = getline(*addr);
		locs = 0;
	}
	p2 = expbuf;
	if (circfl) {
		loc1 = p1;
		return(advance(p1, p2));
	}
	/* fast check for first character */
	if (*p2==CCHR) {
		c = p2[1];
		do {
			if (*p1!=c)
				continue;
			if (advance(p1, p2)) {
				loc1 = p1;
				return(1);
			}
		} while (*p1++);
		return(0);
	}
	/* regular algorithm */
	do {
		if (advance(p1, p2)) {
			loc1 = p1;
			return(1);
		}
	} while (*p1++);
	return(0);
}

advance(alp, aep)
{
	register char *lp, *ep, *curlp;
	char *nextep;

	lp = alp;
	ep = aep;
	for (;;) switch (*ep++) {

	case CCHR:
		if (*ep++ == *lp++)
			continue;
		return(0);

	case CDOT:
		if (*lp++)
			continue;
		return(0);

	case CDOL:
		if (*lp==0)
			continue;
		return(0);

	case CEOF:
		loc2 = lp;
		return(1);

	case CCL:
		if (cclass(ep, *lp++, 1)) {
			ep =+ *ep;
			continue;
		}
		return(0);

	case NCCL:
		if (cclass(ep, *lp++, 0)) {
			ep =+ *ep;
			continue;
		}
		return(0);

	case CBRA:
		braslist[*ep++] = lp;
		continue;

	case CKET:
		braelist[*ep++] = lp;
		continue;

	case CDOT|STAR:
		curlp = lp;
		while (*lp++);
		goto star;

	case CCHR|STAR:
		curlp = lp;
		while (*lp++ == *ep);
		ep++;
		goto star;

	case CCL|STAR:
	case NCCL|STAR:
		curlp = lp;
		while (cclass(ep, *lp++, ep[-1]==(CCL|STAR)));
		ep =+ *ep;
		goto star;

	star:
		do {
			lp--;
			if (lp==locs)
				break;
			if (advance(lp, ep))
				return(1);
		} while (lp > curlp);
		return(0);

	default:
		error;
	}
}

cclass(aset, ac, af)
{
	register char *set, c;
	register n;

	set = aset;
	if ((c = ac) == 0)
		return(0);
	n = *set++;
	while (--n)
		if (*set++ == c)
			return(af);
	return(!af);
}

putd()
{
	register r;
	extern ldivr;

	count[1] = ldiv(count[0], count[1], 10);
	count[0] = 0;
	r = ldivr;
	if (count[1])
		putd();
	putchar(r + '0');
}

puts(as)
{
	register char *sp;

	sp = as;
	col = 0;
	while (*sp)
		putchar(*sp++);
	putchar('\n');
}

char	line[70];
char	*linp	line;

putchar(ac)
{
	register char *lp;
	register c;

	lp = linp;
	c = ac;
	if (listf) {
		col++;
		if (col >= 72) {
			col = 0;
			*lp++ = '\\';
			*lp++ = '\n';
		}
		if (c=='\t') {
			c = '>';
			goto esc;
		}
		if (c=='\b') {
			c = '<';
		esc:
			*lp++ = '-';
			*lp++ = '\b';
			*lp++ = c;
			goto out;
		}
		if (c<' ' && c!= '\n') {
			*lp++ = '\\';
			*lp++ = (c>>3)+'0';
			*lp++ = (c&07)+'0';
			col =+ 2;
			goto out;
		}
	}
	*lp++ = c;
out:
	if(c == '\n' || lp >= &line[64]) {
		linp = line;
		write(1, line, lp-line);
		return;
	}
	linp = lp;
}

/*
 * Get process ID routine if system call is unavailable.
getpid()
{
	register f;
	int b[1];

	f = open("/dev/kmem", 0);
	if(f < 0)
		return(-1);
	seek(f, 0140074, 0);
	read(f, b, 2);
	seek(f, b[0]+8, 0);
	read(f, b, 2);
	close(f);
	return(b[0]);
}
 */