sh.lex.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 1,440 行 · 第 1/2 页

				if (c != delim /* && c != '~' */)
					*cp++ = '\\';
			}
			*cp++ = c;
		}
		*cp++ = 0;
		break;

	default:
		if (c == '\n')
			unreadc(c);
		seterrc("Bad ! modifier: ", (char) c);
		goto ret;
	}
	(void) strcpy(slhs, lhsb);
	if (exclc)
		en = dosub(sc, en, global);
ret:
	return (en);
}

struct wordent *
dosub(sc, en, global)
	int sc;
	struct wordent *en;
	bool global;
{
	struct wordent lex;
	bool didsub = 0;
	struct wordent *hp = &lex;
	register struct wordent *wdp;
	register int i = exclc;

	wdp = hp;
	while (--i >= 0) {
		register struct wordent *new = (struct wordent *) calloc(1, sizeof *wdp);

		new->prev = wdp;
		new->next = hp;
		wdp->next = new;
		wdp = new;
		en = en->next;
		wdp->word = global || didsub == 0 ?
		    subword(en->word, sc, &didsub) : savestr(en->word);
	}
	if (didsub == 0)
		seterr("Modifier failed");
	hp->prev = wdp;
	return (&enthist(-1000, &lex, 0)->Hlex);
}

char *
subword(cp, type, adid)
	char *cp;
	int type;
	bool *adid;
{
	char wbuf[BUFSIZ];
	register char *wp, *mp, *np;
	register int i;

	switch (type) {

	case 'r':
	case 'e':
	case 'h':
	case 't':
	case 'q':
	case 'x':
		wp = domod(cp, type);
		if (wp == 0)
			return (savestr(cp));
		*adid = 1;
		return (wp);

	default:
		wp = wbuf;
		i = BUFSIZ - 4;
		for (mp = cp; *mp; mp++)
			if (matchs(mp, lhsb)) {
				for (np = cp; np < mp;)
					*wp++ = *np++, --i;
				for (np = rhsb; *np; np++) switch (*np) {

				case '\\':
					if (np[1] == '&')
						np++;
					/* fall into ... */

				default:
					if (--i < 0)
						goto ovflo;
					*wp++ = *np;
					continue;

				case '&':
					i -= strlen(lhsb);
					if (i < 0)
						goto ovflo;
					*wp = 0;
					(void) strcat(wp, lhsb);
					wp = strend(wp);
					continue;
				}
				mp += strlen(lhsb);
				i -= strlen(mp);
				if (i < 0) {
ovflo:
					seterr("Subst buf ovflo");
					return ("");
				}
				*wp = 0;
				(void) strcat(wp, mp);
				*adid = 1;
				return (savestr(wbuf));
			}
		return (savestr(cp));
	}
}

char *
domod(cp, type)
	char *cp;
	int type;
{
	char wbuf[BUFSIZ];
	register char *wp, *xp;
	register int c;

	switch (type) {

	case 'x':
	case 'q':
		for (xp = wbuf; c = *cp++; ) {
			if ((c != ' ' && c != '\t') || type == 'q')
				*xp++ = QUOTECHAR;
			*xp++ = c;
		}
		*xp = '\0';
		return (savestr(wbuf));

	case 'h':
	case 't':
		if (!any('/', cp))
			return (type == 't' ? savestr(cp) : 0);
		wp = strend(cp);
		while (*--wp != '/')
			continue;
		if (type == 'h')
			xp = savestr(cp), xp[wp - cp] = 0;
		else
			xp = savestr(wp + 1);
		return (xp);

	case 'e':
	case 'r':
		wp = strend(cp);
		for (wp--; wp >= cp && *wp != '/'; wp--)
			if (*wp == '.') {
				if (type == 'e')
					xp = savestr(wp + 1);
				else
					xp = savestr(cp), xp[wp - cp] = 0;
				return (xp);
			}
		return (savestr(type == 'e' ? "" : cp));
	}
	return (0);
}

matchs(str, pat)
	register char *str, *pat;
{

	while (*str && *pat && *str == *pat)
		str++, pat++;
	return (*pat == 0);
}

getsel(al, ar, dol)
	register int *al, *ar;
	int dol;
{
	register int c = getC(0);
	register int i;
	bool first = *al < 0;

	switch (c) {

	case '%':
		if (quesarg == -1)
			goto bad;
		if (*al < 0)
			*al = quesarg;
		*ar = quesarg;
		break;

	case '-':
		if (*al < 0) {
			*al = 0;
			*ar = dol - 1;
			unreadc(c);
		}
		return (1);

	case '^':
		if (*al < 0)
			*al = 1;
		*ar = 1;
		break;

	case '$':
		if (*al < 0)
			*al = dol;
		*ar = dol;
		break;

	case '*':
		if (*al < 0)
			*al = 1;
		*ar = dol;
		if (*ar < *al) {
			*ar = 0;
			*al = 1;
			return (1);
		}
		break;

	default:
		if (digit(c)) {
			i = 0;
			while (digit(c)) {
				i = i * 10 + c - '0';
				c = getC(0);
			}
			if (i < 0)
				i = dol + 1;
			if (*al < 0)
				*al = i;
			*ar = i;
		} else
			if (*al < 0)
				*al = 0, *ar = dol;
			else
				*ar = dol - 1;
		unreadc(c);
		break;
	}
	if (first) {
		c = getC(0);
		unreadc(c);
		if (any(c, "-$*"))
			return (1);
	}
	if (*al > *ar || *ar > dol) {
bad:
		seterr("Bad ! arg selector");
		return (0);
	}
	return (1);

}

struct wordent *
gethent(sc)
	int sc;
{
	register struct Hist *hp;
	register char *np;
	register int c;
	int event;
	bool back = 0;

	c = sc == HISTSUB ? HIST : getC(0);
	if (c == HIST) {
		if (alhistp)
			return (alhistp);
		event = eventno;
		goto skip;
	}
	switch (c) {

	case ':':
	case '^':
	case '$':
	case '*':
	case '%':
		ungetC(c);
		if (lastev == eventno && alhistp)
			return (alhistp);
		event = lastev;
		break;

	case '-':
		back = 1;
		c = getC(0);
		goto number;

	case '#':			/* !# is command being typed in (mrh) */
		return(&paraml);

	default:
		if (any(c, "(=~")) {
			unreadc(c);
			ungetC(HIST);
			return (0);
		}
		if (digit(c))
			goto number;
		np = lhsb;
		while (!any(c, ": \t\\\n}")) {
			if (np < &lhsb[sizeof lhsb - 2])
				*np++ = c;
			c = getC(0);
		}
		unreadc(c);
		if (np == lhsb) {
			ungetC(HIST);
			return (0);
		}
		*np++ = 0;
		hp = findev(lhsb, 0);
		if (hp)
			lastev = hp->Hnum;
		return (&hp->Hlex);

	case '?':
		np = lhsb;
		for (;;) {
			c = getC(0);
			if (c == '\n') {
				unreadc(c);
				break;
			}
			if (c == '?')
				break;
			if (np < &lhsb[sizeof lhsb - 2])
				*np++ = c;
		}
		if (np == lhsb) {
			if (lhsb[0] == 0) {
				seterr("No prev search");
				return (0);
			}
		} else
			*np++ = 0;
		hp = findev(lhsb, 1);
		if (hp)
			lastev = hp->Hnum;
		return (&hp->Hlex);

	number:
		event = 0;
		while (digit(c)) {
			event = event * 10 + c - '0';
			c = getC(0);
		}
		if (back)
			event = eventno + (alhistp == 0) - (event ? event : 0);
		unreadc(c);
		break;
	}
skip:
	for (hp = Histlist.Hnext; hp; hp = hp->Hnext)
		if (hp->Hnum == event) {
			hp->Href = eventno;
			lastev = hp->Hnum;
			return (&hp->Hlex);
		}
	np = putn(event);
	noev(np);
	return (0);
}

struct Hist *
findev(cp, anyarg)
	char *cp;
	bool anyarg;
{
	register struct Hist *hp;

	for (hp = Histlist.Hnext; hp; hp = hp->Hnext) {
		char *dp;
		register char *p, *q;
		register struct wordent *lp = hp->Hlex.next;
		int argno = 0;

		if (lp->word[0] == '\n')
			continue;
		if (!anyarg) {
			p = cp;
			q = lp->word;
			do
				if (!*p)
					return (hp);
			while (*p++ == *q++);
			continue;
		}
		do {
			for (dp = lp->word; *dp; dp++) {
				p = cp;
				q = dp;
				do
					if (!*p) {
						quesarg = argno;
						return (hp);
					}
				while (*p++ == *q++);
			}
			lp = lp->next;
			argno++;
		} while (lp->word[0] != '\n');
	}
	noev(cp);
	return (0);
}

noev(cp)
	char *cp;
{

	seterr2(cp, ": Event not found");
}

setexclp(cp)
	register char *cp;
{

	if (cp && cp[0] == '\n')
		return;
	exclp = cp;
}

unreadc(c)
	unsigned char c;
{

	peekread = c;
}

readc(wanteof)
	bool wanteof;
{
	register int c;
	static sincereal;

	if (c = peekread) {
		peekread = 0;
		return (c);
	}
top:
	if (alvecp) {
		if (c = *alvecp++)
			return (c);
		if (*alvec) {
			alvecp = *alvec++;
			return (' ');
		}
	}
	if (alvec) {
		if (alvecp = *alvec) {
			alvec++;
			goto top;
		}
		/* Infinite source! */
		return ('\n');
	}
	if (evalp) {
		if (c = *evalp++)
			return (c);
		if (*evalvec) {
			evalp = *evalvec++;
			return (' ');
		}
		evalp = 0;
	}
	if (evalvec) {
		if (evalvec == (char **)1) {
			doneinp = 1;
			reset();
		}
		if (evalp = *evalvec) {
			evalvec++;
			goto top;
		}
		evalvec = (char **)1;
		return ('\n');
	}
	do {
		if (arginp == (char *) 1 || onelflg == 1) {
			if (wanteof)
				return (-1);
			exitstat();
		}
		if (arginp) {
			if ((c = *arginp++) == 0) {
				arginp = (char *) 1;
				return ('\n');
			}
			return (c);
		}
reread:
		c = bgetc();
		if (c == -1) {
			struct sgttyb tty;

			if (wanteof)
				return (-1);
			/* was isatty but raw with ignoreeof yields problems */
			if (ioctl(SHIN, TIOCGETP, (char *)&tty) == 0 &&
			    (tty.sg_flags & RAW) == 0) {
				/* was 'short' for FILEC */
				int ctpgrp;

				if (++sincereal > 25)
					goto oops;
				if (tpgrp != -1 &&
				    ioctl(FSHTTY, TIOCGPGRP, (char *)&ctpgrp) == 0 &&
				    tpgrp != ctpgrp) {
					(void) ioctl(FSHTTY, TIOCSPGRP,
						(char *)&tpgrp);
					(void) killpg(ctpgrp, SIGHUP);
csh_printf("Reset tty pgrp from %d to %d\n", ctpgrp, tpgrp); /* 005 RNF */
					goto reread;
				}
				if (adrof("ignoreeof")) {
					if (loginsh)
						csh_printf("\nUse \"logout\" to logout.\n"); /* 005 RNF */
					else
						csh_printf("\nUse \"exit\" to leave csh.\n"); /* 005 RNF */
					reset();
				}
				if (chkstop == 0)
					panystop(1);
			} else {	/* 002 - GAG */
				/*Perror ("ioctl");*/
			}
oops:
			doneinp = 1;
			reset();
		}
		sincereal = 0;
		if (c == '\n' && onelflg)
			onelflg--;
	} while (c == 0);
	return (c);
}

bgetc()
{
	register int buf, off, c;
	register int roomleft;

#ifdef TENEX
	register int numleft = 0;
	char ttyline[BUFSIZ];
#endif

#ifdef TELL
	if (cantell) {
		if (fseekp < fbobp || fseekp > feobp) {
			fbobp = feobp = fseekp;
			(void) lseek(SHIN, fseekp, 0);
		}
		if (fseekp == feobp) {
			fbobp = feobp;
			do
				c = read(SHIN, fbuf[0], BUFSIZ);
			while (c < 0 && errno == EINTR);
			if (c <= 0)
				return (-1);
			feobp += c;
		}
		c = fbuf[0][fseekp - fbobp];
		fseekp++;
		return (c & TRIM);
	}
#endif
again:
	buf = (int) fseekp / BUFSIZ;
	if (buf >= fblocks) {
		register char **nfbuf =
			(char **) calloc((unsigned) (fblocks + 2),
				sizeof (char **));

		if (fbuf) {
			(void) blkcpy(nfbuf, fbuf);
			xfree((char *)fbuf);
		}
		fbuf = nfbuf;
		fbuf[fblocks] = calloc(BUFSIZ, sizeof (char));
		fblocks++;
		goto again;
	}
	if (fseekp >= feobp) {
		buf = (int) feobp / BUFSIZ;
		off = (int) feobp % BUFSIZ;
		roomleft = BUFSIZ - off;
		for (;;) {			/* break out: see below */
#ifdef TENEX
			if (intty)		/* then use tenex routine */
			{
				c = numleft ? numleft : tenex(ttyline, BUFSIZ);
				if (c > roomleft) /* No room in this buffer? */
				{
					/* start with fresh buffer */
					feobp = fseekp = fblocks * BUFSIZ;
					numleft = c;
					goto again;
				}
				if (c > 0)
					copy (fbuf[buf] + off, ttyline, c);
				numleft = 0;
			}
			else
				c = read(SHIN, fbuf[buf] + off, roomleft);
			if ((c >= 0) || (errno != EINTR))
				break;
#else not tenex
			c = read(SHIN, fbuf[buf] + off, BUFSIZ - off);
			if (c >= 0)
				break;
			if (errno == EWOULDBLOCK) {
				int off = 0;

				(void) ioctl(SHIN, FIONBIO, (char *)&off);
			} else if (errno != EINTR)
				break;
#endif
		} /* end "for (;;)" */
		if (c <= 0)
			return (-1);
		feobp += c;
#ifdef TENEX
		if (!intty)
#endif
		    goto again;
	}
	c = fbuf[buf][(int) fseekp % BUFSIZ];
	fseekp++;
	return (c);
}

bfree()
{
	register int sb, i;

#ifdef TELL
	if (cantell)
		return;
#endif
	if (whyles)
		return;
	sb = (int) (fseekp - 1) / BUFSIZ;
	if (sb > 0) {
		for (i = 0; i < sb; i++)
			xfree(fbuf[i]);
		(void) blkcpy(fbuf, &fbuf[sb]);
		fseekp -= BUFSIZ * sb;
		feobp -= BUFSIZ * sb;
		fblocks -= sb;
	}
}

bseek(l)
	off_t l;
{
	register struct whyle *wp;

	fseekp = l;
#ifdef TELL
	if (!cantell) {
#endif
		if (!whyles)
			return;
		for (wp = whyles; wp->w_next; wp = wp->w_next)
			continue;
		if (wp->w_start > l)
			l = wp->w_start;
#ifdef TELL
	}
#endif
}

/* any similarity to bell telephone is purely accidental */
#ifndef btell
off_t
btell()
{

	return (fseekp);
}
#endif

btoeof()
{

	(void) lseek(SHIN, (off_t)0, 2);
	fseekp = feobp;
	wfree();
	bfree();
}

#ifdef TELL
settell()
{

	cantell = 0;
	if (arginp || onelflg || intty)
		return;
	if (lseek(SHIN, (off_t)0, 1) < 0 || errno == ESPIPE)
		return;
	fbuf = (char **) calloc(2, sizeof (char **));
	fblocks = 1;
	fbuf[0] = calloc(BUFSIZ, sizeof (char));
	fseekp = fbobp = feobp = lseek(SHIN, (off_t)0, 1);
	cantell = 1;
}
#endif