ed.c

unix v7是最后一个广泛发布的研究型UNIX版本

			nl = nleft;
		}
	}
	nl = tline;
	tline += (((lp-linebuf)+03)>>1)&077776;
	return(nl);
}

char *
getblock(atl, iof)
{
	extern read(), write();
	register bno, off;
	register char *p1, *p2;
	register int n;
	
	bno = (atl>>8)&0377;
	off = (atl<<1)&0774;
	if (bno >= 255) {
		lastc = '\n';
		error(T);
	}
	nleft = 512 - off;
	if (bno==iblock) {
		ichanged |= iof;
		return(ibuff+off);
	}
	if (bno==oblock)
		return(obuff+off);
	if (iof==READ) {
		if (ichanged) {
			if(xtflag)
				crblock(tperm, ibuff, 512, (long)0);
			blkio(iblock, ibuff, write);
		}
		ichanged = 0;
		iblock = bno;
		blkio(bno, ibuff, read);
		if(xtflag)
			crblock(tperm, ibuff, 512, (long)0);
		return(ibuff+off);
	}
	if (oblock>=0) {
		if(xtflag) {
			p1 = obuff;
			p2 = crbuf;
			n = 512;
			while(n--)
				*p2++ = *p1++;
			crblock(tperm, crbuf, 512, (long)0);
			blkio(oblock, crbuf, write);
		} else
			blkio(oblock, obuff, write);
	}
	oblock = bno;
	return(obuff+off);
}

blkio(b, buf, iofcn)
char *buf;
int (*iofcn)();
{
	lseek(tfile, (long)b<<9, 0);
	if ((*iofcn)(tfile, buf, 512) != 512) {
		error(T);
	}
}

init()
{
	register *markp;

	close(tfile);
	tline = 2;
	for (markp = names; markp < &names[26]; )
		*markp++ = 0;
	subnewa = 0;
	anymarks = 0;
	iblock = -1;
	oblock = -1;
	ichanged = 0;
	close(creat(tfname, 0600));
	tfile = open(tfname, 2);
	if(xflag) {
		xtflag = 1;
		makekey(key, tperm);
	}
	dot = dol = zero;
}

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

	if (globp)
		error(Q);
	setall();
	nonzero();
	if ((c=getchr())=='\n')
		error(Q);
	compile(c);
	gp = globuf;
	while ((c = getchr()) != '\n') {
		if (c==EOF)
			error(Q);
		if (c=='\\') {
			c = getchr();
			if (c!='\n')
				*gp++ = '\\';
		}
		*gp++ = c;
		if (gp >= &globuf[GBSIZE-2])
			error(Q);
	}
	*gp++ = '\n';
	*gp++ = 0;
	for (a1=zero; a1<=dol; a1++) {
		*a1 &= ~01;
		if (a1>=addr1 && a1<=addr2 && execute(0, a1)==k)
			*a1 |= 01;
	}
	/*
	 * Special case: g/.../d (avoid n^2 algorithm)
	 */
	if (globuf[0]=='d' && globuf[1]=='\n' && globuf[2]=='\0') {
		gdelete();
		return;
	}
	for (a1=zero; a1<=dol; a1++) {
		if (*a1 & 01) {
			*a1 &= ~01;
			dot = a1;
			globp = globuf;
			commands();
			a1 = zero;
		}
	}
}

join()
{
	register char *gp, *lp;
	register *a1;

	gp = genbuf;
	for (a1=addr1; a1<=addr2; a1++) {
		lp = getline(*a1);
		while (*gp = *lp++)
			if (gp++ >= &genbuf[LBSIZE-2])
				error(Q);
	}
	lp = linebuf;
	gp = genbuf;
	while (*lp++ = *gp++)
		;
	*addr1 = putline();
	if (addr1<addr2)
		rdelete(addr1+1, addr2);
	dot = addr1;
}

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

	gsubf = compsub();
	for (a1 = addr1; a1 <= addr2; a1++) {
		int *ozero;
		if (execute(0, a1)==0)
			continue;
		inglob |= 01;
		dosub();
		if (gsubf) {
			while (*loc2) {
				if (execute(1, (int *)0)==0)
					break;
				dosub();
			}
		}
		subnewa = putline();
		*a1 &= ~01;
		if (anymarks) {
			for (markp = names; markp < &names[26]; markp++)
				if (*markp == *a1)
					*markp = subnewa;
		}
		subolda = *a1;
		*a1 = subnewa;
		ozero = zero;
		nl = append(getsub, a1);
		nl += zero-ozero;
		a1 += nl;
		addr2 += nl;
	}
	if (inglob==0)
		error(Q);
}

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

	if ((seof = getchr()) == '\n' || seof == ' ')
		error(Q);
	compile(seof);
	p = rhsbuf;
	for (;;) {
		c = getchr();
		if (c=='\\')
			c = getchr() | 0200;
		if (c=='\n') {
			if (globp)
				c |= 0200;
			else
				error(Q);
		}
		if (c==seof)
			break;
		*p++ = c;
		if (p >= &rhsbuf[LBSIZE/2])
			error(Q);
	}
	*p++ = 0;
	if ((peekc = getchr()) == '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++&0377) {
		if (c=='&') {
			sp = place(sp, loc1, loc2);
			continue;
		} else if (c&0200 && (c &= 0177) >='1' && c < nbra+'1') {
			sp = place(sp, braslist[c-'1'], braelist[c-'1']);
			continue;
		}
		*sp++ = c&0177;
		if (sp >= &genbuf[LBSIZE])
			error(Q);
	}
	lp = loc2;
	loc2 = sp - genbuf + linebuf;
	while (*sp++ = *lp++)
		if (sp >= &genbuf[LBSIZE])
			error(Q);
	lp = linebuf;
	sp = genbuf;
	while (*lp++ = *sp++)
		;
}

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

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

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

	setdot();
	nonzero();
	if ((adt = address())==0)
		error(Q);
	newline();
	if (cflag) {
		int *ozero, delta;
		ad1 = dol;
		ozero = zero;
		append(getcopy, ad1++);
		ad2 = dol;
		delta = zero - ozero;
		ad1 += delta;
		adt += delta;
	} else {
		ad2 = addr2;
		for (ad1 = addr1; ad1 <= ad2;)
			*ad1++ &= ~01;
		ad1 = addr1;
	}
	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(Q);
	fchange = 1;
}

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

	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 cclcnt;

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

		case '\\':
			if ((c = getchr())=='(') {
				if (nbra >= NBRA)
					goto cerror;
				*bracketp++ = nbra;
				*ep++ = CBRA;
				*ep++ = nbra++;
				continue;
			}
			if (c == ')') {
				if (bracketp <= bracket)
					goto cerror;
				*ep++ = CKET;
				*ep++ = *--bracketp;
				continue;
			}
			if (c>='1' && c<'1'+NBRA) {
				*ep++ = CBACK;
				*ep++ = c-'1';
				continue;
			}
			*ep++ = CCHR;
			if (c=='\n')
				goto cerror;
			*ep++ = c;
			continue;

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

		case '\n':
			goto cerror;

		case '*':
			if (lastep==0 || *lastep==CBRA || *lastep==CKET)
				goto defchar;
			*lastep |= STAR;
			continue;

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

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

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

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

	for (c=0; c<NBRA; c++) {
		braslist[c] = 0;
		braelist[c] = 0;
	}
	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(lp, ep)
register char *ep, *lp;
{
	register char *curlp;
	int i;

	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 CBACK:
		if (braelist[i = *ep++]==0)
			error(Q);
		if (backref(i, lp)) {
			lp += braelist[i] - braslist[i];
			continue;
		}
		return(0);

	case CBACK|STAR:
		if (braelist[i = *ep++] == 0)
			error(Q);
		curlp = lp;
		while (backref(i, lp))
			lp += braelist[i] - braslist[i];
		while (lp >= curlp) {
			if (advance(lp, ep))
				return(1);
			lp -= braelist[i] - braslist[i];
		}
		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(Q);
	}
}

backref(i, lp)
register i;
register char *lp;
{
	register char *bp;

	bp = braslist[i];
	while (*bp++ == *lp++)
		if (bp >= braelist[i])
			return(1);
	return(0);
}

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

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

putd()
{
	register r;

	r = count%10;
	count /= 10;
	if (count)
		putd();
	putchr(r + '0');
}

puts(sp)
register char *sp;
{
	col = 0;
	while (*sp)
		putchr(*sp++);
	putchr('\n');
}

char	line[70];
char	*linp	= line;

putchr(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;
}
crblock(permp, buf, nchar, startn)
char *permp;
char *buf;
long startn;
{
	register char *p1;
	int n1;
	int n2;
	register char *t1, *t2, *t3;

	t1 = permp;
	t2 = &permp[256];
	t3 = &permp[512];

	n1 = startn&0377;
	n2 = (startn>>8)&0377;
	p1 = buf;
	while(nchar--) {
		*p1 = t2[(t3[(t1[(*p1+n1)&0377]+n2)&0377]-n2)&0377]-n1;
		n1++;
		if(n1==256){
			n1 = 0;
			n2++;
			if(n2==256) n2 = 0;
		}
		p1++;
	}
}

getkey()
{
	struct sgttyb b;
	int save;
	int (*sig)();
	register char *p;
	register c;

	sig = signal(SIGINT, SIG_IGN);
	if (gtty(0, &b) == -1)
		error("Input not tty");
	save = b.sg_flags;
	b.sg_flags &= ~ECHO;
	stty(0, &b);
	puts("Key:");
	p = key;
	while(((c=getchr()) != EOF) && (c!='\n')) {
		if(p < &key[KSIZE])
			*p++ = c;
	}
	*p = 0;
	b.sg_flags = save;
	stty(0, &b);
	signal(SIGINT, sig);
	return(key[0] != 0);
}

/*
 * Besides initializing the encryption machine, this routine
 * returns 0 if the key is null, and 1 if it is non-null.
 */
crinit(keyp, permp)
char	*keyp, *permp;
{
	register char *t1, *t2, *t3;
	register i;
	int ic, k, temp, pf[2];
	unsigned random;
	char buf[13];
	long seed;

	t1 = permp;
	t2 = &permp[256];
	t3 = &permp[512];
	if(*keyp == 0)
		return(0);
	strncpy(buf, keyp, 8);
	while (*keyp)
		*keyp++ = '\0';
	buf[8] = buf[0];
	buf[9] = buf[1];
	if (pipe(pf)<0)
		pf[0] = pf[1] = -1;
	if (fork()==0) {
		close(0);
		close(1);
		dup(pf[0]);
		dup(pf[1]);
		execl("/usr/lib/makekey", "-", 0);
		execl("/lib/makekey", "-", 0);
		exit(1);
	}
	write(pf[1], buf, 10);
	if (wait((int *)NULL)==-1 || read(pf[0], buf, 13)!=13)
		error("crypt: cannot generate key");
	close(pf[0]);
	close(pf[1]);
	seed = 123;
	for (i=0; i<13; i++)
		seed = seed*buf[i] + i;
	for(i=0;i<256;i++){
		t1[i] = i;
		t3[i] = 0;
	}
	for(i=0; i<256; i++) {
		seed = 5*seed + buf[i%13];
		random = seed % 65521;
		k = 256-1 - i;
		ic = (random&0377) % (k+1);
		random >>= 8;
		temp = t1[k];
		t1[k] = t1[ic];
		t1[ic] = temp;
		if(t3[k]!=0) continue;
		ic = (random&0377) % k;
		while(t3[ic]!=0) ic = (ic+1) % k;
		t3[k] = ic;
		t3[ic] = k;
	}
	for(i=0; i<256; i++)
		t2[t1[i]&0377] = i;
	return(1);
}

makekey(a, b)
char *a, *b;
{
	register int i;
	long t;
	char temp[KSIZE + 1];

	for(i = 0; i < KSIZE; i++)
		temp[i] = *a++;
	time(&t);
	t += getpid();
	for(i = 0; i < 4; i++)
		temp[i] ^= (t>>(8*i))&0377;
	crinit(temp, b);
}