sh.dol.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 768 行 · 第 1/2 页

		 */
		dolmod = 'q';
		dolmcnt = 10000;
		setDolp(wbuf);
		goto eatbrac;

	case DEOF:
	case '\n':
		goto syntax;

	case '*':
		(void) strcpy(name, "argv");
		vp = adrof("argv");
		subscr = -1;			/* Prevent eating [...] */
		break;

	default:
		np = name;
		if (digit(c)) {
			if (dimen)
				goto syntax;	/* No $#1, e.g. */
			subscr = 0;
			do {
				subscr = subscr * 10 + c - '0';
				c = DgetC(0);
			} while (digit(c));
			unDredc(c);
			if (subscr < 0)
				goto oob;
			if (subscr == 0) {
				if (bitset) {
					dolp = file ? "1" : "0";
					goto eatbrac;
				}
				if (file == 0)
					error("No file for $0");
				setDolp(file);
				goto eatbrac;
			}
			if (bitset)
				goto syntax;
			vp = adrof("argv");
			if (vp == 0) {
				vp = &nulargv;
				goto eatmod;
			}
			break;
		}
		/* GT01: must start with an alphabetic */
		if (!letter(c))
			goto syntax;
		for (;;) {
			*np++ = c;
			c = DgetC(0);
			if (!alnum(c))
				break;
			if (np >= &name[sizeof name - 2])
syntax:
				error("Variable syntax");
		}
		*np++ = 0;
		unDredc(c);
		vp = adrof(name);
	}
	if (bitset) {
		dolp = (vp || getenv(name)) ? "1" : "0";
		goto eatbrac;
	}
	if (vp == 0) {
		np = getenv(name);
		if (np) {
			addla(np);
			goto eatbrac;
		}
		udvar(name);
		/*NOTREACHED*/
	}
	c = DgetC(0);
	upb = blklen(vp->vec);
	if (dimen == 0 && subscr == 0 && c == '[') {
		np = name;
		for (;;) {
			c = DgetC(DODOL);	/* Allow $ expand within [ ] */
			if (c == ']')
				break;
			if (c == '\n' || c == DEOF)
				goto syntax;
			if (np >= &name[sizeof name - 2])
				goto syntax;
			*np++ = c;
		}
		*np = 0, np = name;
		if (dolp || dolcnt)		/* $ exp must end before ] */
			goto syntax;
		if (!*np)
			goto syntax;
		if (digit(*np)) {
			register int i = 0;

			while (digit(*np))
				i = i * 10 + *np++ - '0';
			if ((i < 0 || i > upb) && !any(*np, "-*")) {
oob:
				setname(vp->v_name);
				error("Subscript out of range");
			}
			lwb = i;
			if (!*np)
				upb = lwb, np = "*";
		}
		if (*np == '*')
			np++;
		else if (*np != '-')
			goto syntax;
		else {
			register int i = upb;

			np++;
			if (digit(*np)) {
				i = 0;
				while (digit(*np))
					i = i * 10 + *np++ - '0';
				if (i < 0 || i > upb)
					goto oob;
			}
			if (i < lwb)
				upb = lwb - 1;
			else
				upb = i;
		}
		if (lwb == 0) {
			if (upb != 0)
				goto oob;
			upb = -1;
		}
		if (*np)
			goto syntax;
	} else {
		if (subscr > 0)
			if (subscr > upb)
				lwb = 1, upb = 0;
			else
				lwb = upb = subscr;
		unDredc(c);
	}
	if (dimen) {
		char *cp = putn(upb - lwb + 1);

		addla(cp);
		xfree(cp);
	} else {
eatmod:
		c = DgetC(0);
		if (c == ':') {
			c = DgetC(0), dolmcnt = 1;
			if (c == 'g')
				c = DgetC(0), dolmcnt = 10000;
			if (!any(c, "htrqxe"))
				error("Bad : mod in $");
			dolmod = c;
			if (c == 'q')
				dolmcnt = 10000;
		} else
			unDredc(c);
		dolnxt = &vp->vec[lwb - 1];
		dolcnt = upb - lwb + 1;
	}
eatbrac:
	if (sc == '{') {
		c = Dredc();
		if (c != '}')
			goto syntax;
	}
}

setDolp(cp)
	register char *cp;
{
	register char *dp;

	if (dolmod == 0 || dolmcnt == 0) {
		dolp = cp;
		return;
	}
	dp = domod(cp, dolmod);
	if (dp) {
		dolmcnt--;
		addla(dp);
		xfree(dp);
	} else
		addla(cp);
	dolp = "";
}

unDredc(c)
	int c;
{

	Dpeekrd = c;
}

Dredc()
{
	register int c;

	if (c = Dpeekrd) {
		Dpeekrd = 0;
		return (c);
	}
	if (Dcp && (c = *Dcp++)) {
		if ((c  & TRIM) == QUOTECHAR)
			c = (*Dcp++ & TRIM) | QUOTE;
		return (c&(QUOTE|TRIM));
	}
	if (*Dvp == 0) {
		Dcp = 0;
		return (DEOF);
	}
	Dcp = *Dvp++;
	return (' ');
}

Dtestq(c)
	register int c;
{

	if (any(c, "\\'\"`"))
		gflag = 1;
}

/*
 * Form a shell temporary file (in unit 0) from the words
 * of the shell input up to a line the same as "term".
 * Unit 0 should have been closed before this call.
 */
heredoc(term)
	char *term;
{
	register int c;
	char *Dv[2];
	char obuf[BUFSIZ], lbuf[BUFSIZ], mbuf[BUFSIZ];
	int ocnt, lcnt, mcnt;
	register char *lbp, *obp, *mbp;
	char **vp;
	bool quoted;

	if (creat(shtemp, 0600) < 0)
		Perror(shtemp);
	(void) close(0);
	if (open(shtemp, 2) < 0) {
		int oerrno = errno;

		(void) unlink(shtemp);
		errno = oerrno;
		Perror(shtemp);
	}
	(void) unlink(shtemp);			/* 0 0 inode! */
	Dv[0] = term; Dv[1] = NOSTR; gflag = 0;
	trim(Dv); rscan(Dv, Dtestq); quoted = gflag;
	ocnt = BUFSIZ; obp = obuf;
	for (;;) {
		/*
		 * Read up a line
		 */
		lbp = lbuf; lcnt = BUFSIZ - 4;
		for (;;) {
			c = readc(1);		/* 1 -> Want EOF returns */
			if (c == (-1)) {	/* ARG - compare correctly */
				setname(term);
				bferr("<< terminator not found");
			}
			if (c == '\n')
				break;
			if (c &= TRIM) {
				*lbp++ = c;
				if (--lcnt < 0) {
					setname("<<");
					error("Line overflow");
				} 
			}
		}
		*lbp = 0;

		/*
		 * Compare to terminator -- before expansion
		 */
		if (eq(lbuf, term)) {
			(void) write(0, obuf, BUFSIZ - ocnt);
			(void) lseek(0, (off_t)0, 0);
			return;
		}

		/*
		 * If term was quoted or -n just pass it on
		 */
		if (quoted || noexec) {
			*lbp++ = '\n'; *lbp = 0;
			for (lbp = lbuf; c = *lbp++;) {
				*obp++ = c;
				if (--ocnt == 0) {
					(void) write(0, obuf, BUFSIZ);
					obp = obuf; ocnt = BUFSIZ;
				}
			}
			continue;
		}

		/*
		 * Term wasn't quoted so variable and then command
		 * expand the input line
		 */
		Dcp = lbuf; Dvp = Dv + 1; mbp = mbuf; mcnt = BUFSIZ - 4;
		for (;;) {
			c = DgetC(DODOL);
			if (c == DEOF)
				break;
			if ((c &= TRIM) == 0)
				continue;
			/* \ quotes \ $ ` here */
			if (c =='\\') {
				c = DgetC(0);
				if (!any(c, "$\\`"))
					unDgetC(c | QUOTE), c = '\\';
				else
					*mbp++ = QUOTECHAR, c |= QUOTE;	/* 003 - GAG */
			}
			*mbp++ = c & TRIM;	/* 003 - GAG */
			if (--mcnt == 0) {
				setname("<<");
				bferr("Line overflow");
			}
		}
		*mbp = 0;	/* 003 - GAG */

		/*
		 * If any ` in line do command substitution
		 */
		for (mbp = mbuf; *mbp; mbp++) {
			if ((*mbp & TRIM) == QUOTECHAR)
				mbp++;
			else if (any(*mbp, "`")) {
				/*
				 * 1 arg to dobackp causes substitution to be literal.
				 * Words are broken only at newlines so that all blanks
				 * and tabs are preserved.  Blank lines (null words)
				 * are not discarded.
				 */
				vp = dobackp(mbuf, 1);
				break;
			}
		}
		if (!*mbp) {	/* no ` in string; mbp points to NULL */
			mbp = mbuf;
			/* Setup trivial vector similar to return of dobackp */
			Dv[0] = mbp, Dv[1] = NOSTR, vp = Dv;
		}
		/*
		 * Resurrect the words from the command substitution
		 * each separated by a newline.  Note that the last
		 * newline of a command substitution will have been
		 * discarded, but we put a newline after the last word
		 * because this represents the newline after the last
		 * input line!
		 */
		trim (vp);	/* 003 - GAG */
		for (; *vp; vp++) {
			for (mbp = *vp; *mbp; mbp++) {
				*obp++ = *mbp & TRIM;
				if (--ocnt == 0) {
					(void) write(0, obuf, BUFSIZ);
					obp = obuf; ocnt = BUFSIZ;
				}
			}
			*obp++ = '\n';
			if (--ocnt == 0) {
				(void) write(0, obuf, BUFSIZ);
				obp = obuf; ocnt = BUFSIZ;
			}
		}
		if (pargv)
			blkfree(pargv), pargv = 0;
	}
}