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

#ifndef lint
static  char    *sccsid = "@(#)sh.lex.c	4.2  (ULTRIX)        8/13/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1988 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

#include "sh.h"
#include <sgtty.h>

/*
 * C shell
 * Modification History:	sh.lex.c
 *
 * 005 - Bob Fontaine	-  Fri Jun 22 09:53:01 EDT 1990
 *	 Changed call to internal printf function to csh_printf to avoid
 *	 confusion with stdio library routine.
 *
 * 004 - Gary A. Gaudet - Tue Jan  2 11:43:04 EST 1990
 *	changed register char *wp to register unsigned char
 *	changed char wbuf[] to unsigned char wbuf[]
 *	added some (castings)
 *	added return value check for ioctl()
 *
 * 03 12-Nov-88, Al Delorey (afd)
 *	ifdef the TENEX & CSHEDIT code.
 *
 * 02 20-Sep-88, Al Delorey (afd).
 *	Removed Mips tsh code (file completion & line edit).
 *	Added 'tenex' completion & dcsh style command line edit capability.
 *	Major mod to "bgetc()" for completion.
 *
 * 01 Sat Aug 13 15:28:57 EDT 1988, Gary A. Gaudet
 *	merging mips & ultrix for 8 bit clean and bug fixes
 */

/*
 * These lexical routines read input and form lists of words.
 * There is some involved processing here, because of the complications
 * of input buffering, and especially because of history substitution.
 */

char	*word();
#ifdef CSHEDIT
char	*editword();
#endif

/*
 * Peekc is a peek characer for getC, peekread for readc.
 * There is a subtlety here in many places... history routines
 * will read ahead and then insert stuff into the input stream.
 * If they push back a character then they must push it behind
 * the text substituted by the history substitution.  On the other
 * hand in several places we need 2 peek characters.  To make this
 * all work, the history routines read with getC, and make use both
 * of ungetC and unreadc.  The key observation is that the state
 * of getC at the call of a history reference is such that calls
 * to getC from the history routines will always yield calls of
 * readc, unless this peeking is involved.  That is to say that during
 * getexcl the variables lap, exclp, and exclnxt are all zero.
 *
 * Getdol invokes history substitution, hence the extra peek, peekd,
 * which it can ungetD to be before history substitutions.
 */
CHTYPE	peekc, peekd;
CHTYPE	peekread;

char	*exclp;			/* (Tail of) current word from ! subst */
struct	wordent *exclnxt;	/* The rest of the ! subst words */
int	exclc;			/* Count of remainig words in ! subst */
char	*alvecp;		/* "Globp" for alias resubstitution */

/*
 * Lex returns to its caller not only a wordlist (as a "var" parameter)
 * but also whether a history substitution occurred.  This is used in
 * the main (process) routine to determine whether to echo, and also
 * when called by the alias routine to determine whether to keep the
 * argument list.
 */
bool	hadhist;

CHTYPE getCtmp;
#define getC(f)		((getCtmp = peekc) ? (peekc = 0, getCtmp) : getC1(f))
#define	ungetC(c)	peekc = c
#define	ungetD(c)	peekd = c

#ifdef CSHEDIT
lex(hp, didedit)
	register struct wordent *hp;
	int didedit;			/* set true if we edited a cmd line */
#else
lex(hp)
	register struct wordent *hp;
#endif
{
	register struct wordent *wdp;
	int c;

	lineloc = btell();
	hp->next = hp->prev = hp;
	hp->word = "";
	alvecp = 0, hadhist = 0;
#ifdef CSHEDIT
	if (! didedit) {
#endif
		do
			c = readc(0);
		while (c == ' ' || c == '\t'); /* strip leading spaces and tabs */
		if (c == HISTSUB && intty)
			/* ^lef^rit	from tty is short !:s^lef^rit */
			getexcl(c);
		else
			unreadc(c);
#ifdef CSHEDIT
	}
#endif
	wdp = hp;
	/*
	 * The following loop is written so that the links needed
	 * by freelex will be ready and rarin to go even if it is
	 * interrupted.
	 */
	do {
		register struct wordent *new = (struct wordent *) xalloc((unsigned)sizeof *wdp);

		new->word = 0;
		new->prev = wdp;
		new->next = hp;
		wdp->next = new;
		wdp = new;
#ifdef CSHEDIT
		wdp->word = (didedit ? editword() : word());
#else
		wdp->word = word();
#endif
	} while (wdp->word[0] != '\n');
	hp->prev = wdp;
	return (hadhist);
}

prlex(sp0)
	struct wordent *sp0;
{
	register struct wordent *sp = sp0->next;
	char *stripstr;

	for (;;) {
		stripstr = savestr(sp->word);
		csh_printf("%s", strip(stripstr)); 	/* 005 RNF */
		xfree(stripstr);
		sp = sp->next;
		if (sp == sp0)
			break;
		if (sp->word[0] != '\n')
			putchar(' ');
	}
}

copylex(hp, fp)
	register struct wordent *hp;
	register struct wordent *fp;
{
	register struct wordent *wdp;

	wdp = hp;
	fp = fp->next;
	do {
		register struct wordent *new = (struct wordent *) xalloc((unsigned)sizeof *wdp);

		new->prev = wdp;
		new->next = hp;
		wdp->next = new;
		wdp = new;
		wdp->word = savestr(fp->word);
		fp = fp->next;
	} while (wdp->word[0] != '\n');
	hp->prev = wdp;
}

freelex(vp)
	register struct wordent *vp;
{
	register struct wordent *fp;

	while (vp->next != vp) {
		fp = vp->next;
		vp->next = fp->next;
		XFREE(fp->word)
		XFREE((char *)fp)
	}
	vp->prev = vp;
}

char *
word()
{
	register CHTYPE c, c1;
	register unsigned char *wp;	/* 004 - GAG */
	unsigned char wbuf[BUFSIZ*2];	/* 004 - GAG */
	register bool dolflg;
	register int i;

	wp = wbuf;
	i = BUFSIZ*2 - 4*2;
loop:
	while ((c = getC(DOALL)) == ' ' || c == '\t')
		;
	if (any(c, "\t\n #&();<>|\\")) {
		switch (c) {
		case '&':
		case '|':
		case '<':
		case '>':
			*wp++ = c;
			c1 = getC(DOALL);
			if (c1 == c)
				*wp++ = c1;
			else
				ungetC(c1);
			goto ret;

		case '#':
			if (intty)
				break;
			c = 0;
			do {
				c1 = c;
				c = getC(0);
			} while (c != '\n');
			if (c1 == '\\')
				goto loop;
			/* fall into ... */

		case ';':
		case '(':
		case ')':
		case '\n':
			*wp++ = c;
			goto ret;

		case '\\':
			c = getC(0);
			if (c == '\n') {
				if (onelflg == 1)
					onelflg = 2;
				goto loop;
			}
			if (c != HIST)
				*wp++ = '\\', --i;
			c |= QUOTE;
		}
	}
	c1 = 0;
	dolflg = DOALL;
	for (;;) {
		if (c1) {
			if (c == c1) {
				c1 = 0;
				dolflg = DOALL;
			} else if (c == '\\') {
				c = getC(0);
				if (c == HIST)
					c |= QUOTE;
				else {
					if (c == '\n')
						/*
						if (c1 == '`')
							c = ' ';
						else
						*/
							c |= QUOTE;
					ungetC(c);
					c = '\\';
				}
			} else if (c == '\n') {
				seterrc("Unmatched ", (char) c1);
				ungetC(c);
				break;
			}
			} else if (any(c, "\t\n #&();<>|\"'`\\")) {
			if (c == '\\') {
				c = getC(0);
				if (c == '\n') {
					if (onelflg == 1)
						onelflg = 2;
					break;
				}
				if (c != HIST)
					*wp++ = '\\', --i;
				c |= QUOTE;
			} else if (any(c, "\"`'")) {
				c1 = c;
				dolflg = c == '"' ? DOALL : DOEXCL;
			} else if (c != '#' || !intty) {
				ungetC(c);
				break;
			}
		}
		if (--i > 0) {
			if ((c & QUOTE) || (c == QUOTECHAR)) {
				*wp++ = QUOTECHAR;
				i--;
			}
			*wp++ = c & TRIM;
			c = getC(dolflg);
		} else {
			seterr("Word too long");
			wp = &wbuf[1];
			break;
		}
	}
ret:
	*wp = 0;
	return (savestr(wbuf));
}

getC1(flag)
	register int flag;
{
	register CHTYPE c;

top:
	if (c = peekc) {
		peekc = 0;
		return (c);
	}
	if (lap) {
		if ((c = *lap++) == 0)
			lap = 0;
		else {
			if (any(c, "\t\n #&();<>|\"'`"))
				c |= QUOTE;
			return (c);
		}
	}
	if (c = peekd) {
		peekd = 0;
		return (c);
	}
	if (exclp) {
				/* restore Quote bit !!! */
		if ((c = (*exclp++ & TRIM)) == QUOTECHAR)
			c = QUOTE | (*exclp++ & TRIM);
		if (c)
			return (c);
		if (exclnxt && --exclc >= 0) {
			exclnxt = exclnxt->next;
			setexclp(exclnxt->word);
			return (' ');
		}
		exclp = 0;
		exclnxt = 0;
	}
	if (exclnxt) {
		exclnxt = exclnxt->next;
		if (--exclc < 0)
			exclnxt = 0;
		else
			setexclp(exclnxt->word);
		goto top;
	}
	c = readc(0);
	if (c == '$' && (flag & DODOL)) {
		getdol();
		goto top;
	}
	if (c == HIST && (flag & DOEXCL)) {
		getexcl(0);
		goto top;
	}
	return (c);
}

getdol()
{
	register char *np;
	char name[40];
	register int c;
	int sc;
	bool special = 0;

	np = name, *np++ = '$';
	c = sc = getC(DOEXCL);
	if (any(c, "\t \n")) {
		ungetD(c);
		ungetC('$' | QUOTE);
		return;
	}
	if (c == '{')
		*np++ = c, c = getC(DOEXCL);
	if (c == '#' || c == '?')
		special++, *np++ = c, c = getC(DOEXCL);
	*np++ = c;
	switch (c) {
	
	case '<':
	case '$':
		if (special)
			goto vsyn;
		goto ret;

	case '\n':
		ungetD(c);
		np--;
		goto vsyn;

	case '*':
		if (special)
			goto vsyn;
		goto ret;

	default:
		if (digit(c)) {
/*
 * let $?0 pass for now
			if (special)
				goto vsyn;
*/
			while (digit(c = getC(DOEXCL))) {
				if (np < &name[sizeof name / 2])
					*np++ = c;
			}
		/*
		 GT01: changed letter() to alnum() below to allow
		 variables like a2z to be expanded.

		 No, is it a valid variable name?
		*/
		} else if (alnum(c)) {
/*
 *			alnum(c) is a macro
 *			getC(DOEXCL) will execute twice
 *			so don't use alnum(c = getC(DOEXCL)
 */
			c = getC(DOEXCL);
			while (alnum(c)) {
				if (np < &name[sizeof name / 2])
					*np++ = c;
				c = getC(DOEXCL);
			}
		 } else
			goto vsyn;
	}
	if (c == '[') {
		*np++ = c;
		do {
			c = getC(DOEXCL);
			if (c == '\n') {
				ungetD(c);
				np--;
				goto vsyn;
			}
			if (np >= &name[sizeof name - 8])
				goto vsyn;
			*np++ = c;
		} while (c != ']');
		c = getC(DOEXCL);
	}
	if (c == ':') {
		*np++ = c, c = getC(DOEXCL);
		if (c == 'g')
			*np++ = c, c = getC(DOEXCL);
		*np++ = c;
		if (!any(c, "htrqxe"))
			goto vsyn;
	} else
		ungetD(c);
	if (sc == '{') {
		c = getC(DOEXCL);
		if (c != '}') {
			ungetC(c);
			goto vsyn;
		}
		*np++ = c;
	}
ret:
	*np = 0;
	addla(name);
	return;

vsyn:
	seterr("Variable syntax");
	goto ret;
}

addla(cp)
	char *cp;
{
	char buf[BUFSIZ];

	if (lap != 0 && strlen(cp) + strlen(lap) >= sizeof (labuf) - 4) {
		seterr("Expansion buf ovflo");
		return;
	}
	if (lap)
		(void) strcpy(buf, lap);
	(void) strcpy(labuf, cp);
	if (lap)
		(void) strcat(labuf, buf);
	lap = labuf;
}

char	lhsb[32];
char	slhs[32];
char	rhsb[64];
int	quesarg;

getexcl(sc)
	char sc;
{
	register struct wordent *hp, *ip;
	int left, right, dol;
	register int c;

	if (sc == 0) {
		sc = getC(0);
		if (sc != '{') {
			ungetC(sc);
			sc = 0;
		}
	}
	quesarg = -1;
	lastev = eventno;
	hp = gethent(sc);
	if (hp == 0)
		return;
	hadhist = 1;
	dol = 0;
	if (hp == alhistp)
		for (ip = hp->next->next; ip != alhistt; ip = ip->next)
			dol++;
	else
		for (ip = hp->next->next; ip != hp->prev; ip = ip->next)
			dol++;
	left = 0, right = dol;
	if (sc == HISTSUB) {
		ungetC('s'), unreadc(HISTSUB), c = ':';
		goto subst;
	}
	c = getC(0);
	if (!any(c, ":^$*-%"))
		goto subst;
	left = right = -1;
	if (c == ':') {
		c = getC(0);
		unreadc(c);
		if (letter(c) || c == '&') {
			c = ':';
			left = 0, right = dol;
			goto subst;
		}
	} else
		ungetC(c);
	if (!getsel(&left, &right, dol))
		return;
	c = getC(0);
	if (c == '*')
		ungetC(c), c = '-';
	if (c == '-') {
		if (!getsel(&left, &right, dol))
			return;
		c = getC(0);
	}
subst:
	exclc = right - left + 1;
	while (--left >= 0)
		hp = hp->next;
	if (sc == HISTSUB || c == ':') {
		do {
			hp = getsub(hp);
			c = getC(0);
		} while (c == ':');
	}
	unreadc(c);
	if (sc == '{') {
		c = getC(0);
		if (c != '}')
			seterr("Bad ! form");
	}
	exclnxt = hp;
}

struct wordent *
getsub(en)
	struct wordent *en;
{
	register char *cp;
	int delim;
	register int c;
	int sc;
	bool global = 0;
	char orhsb[sizeof rhsb];

	exclnxt = 0;
	sc = c = getC(0);
	if (c == 'g')
		global++, c = getC(0);
	switch (c) {

	case 'p':
		justpr++;
		goto ret;

#ifdef CSHEDIT
	case 'v':			/* modifier for line edit - afd */
		editline++;
		goto ret;
#endif

	case 'x':
	case 'q':
		global++;
		/* fall into ... */

	case 'h':
	case 'r':
	case 't':
	case 'e':
		break;

	case '&':
		if (slhs[0] == 0) {
			seterr("No prev sub");
			goto ret;
		}
		(void) strcpy(lhsb, slhs);
		break;

/*
	case '~':
		if (lhsb[0] == 0)
			goto badlhs;
		break;
*/

	case 's':
		delim = getC(0);
		if (letter(delim) || digit(delim) || any(delim, " \t\n")) {
			unreadc(delim);
bads:
			lhsb[0] = 0;
			seterr("Bad substitute");
			goto ret;
		}
		cp = lhsb;
		for (;;) {
			c = getC(0);
			if (c == '\n') {
				unreadc(c);
				break;
			}
			if (c == delim)
				break;
			if (cp > &lhsb[sizeof lhsb - 2])
				goto bads;
			if (c == '\\') {
				c = getC(0);
				if (c != delim && c != '\\')
					*cp++ = '\\';
			}
			*cp++ = c;
		}
		if (cp != lhsb)
			*cp++ = 0;
		else if (lhsb[0] == 0) {
/*badlhs:*/
			seterr("No prev lhs");
			goto ret;
		}
		cp = rhsb;
		(void) strcpy(orhsb, cp);
		for (;;) {
			c = getC(0);
			if (c == '\n') {
				unreadc(c);
				break;
			}
			if (c == delim)
				break;
/*
			if (c == '~') {
				if (&cp[strlen(orhsb)] > &rhsb[sizeof rhsb - 2])
					goto toorhs;
				(void) strcpy(cp, orhsb);
				cp = strend(cp);
				continue;
			}
*/
			if (cp > &rhsb[sizeof rhsb - 2]) {
/*toorhs:*/
				seterr("Rhs too long");
				goto ret;
			}
			if (c == '\\') {
				c = getC(0);