sh.exp.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 635 行

#ifndef lint
static char *sccsid = "@(#)sh.exp.c	4.2  (ULTRIX)        8/13/90";
#endif
/************************************************************************
 *                                                                      *
 *                      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.                   *
 *                                                                      *
 *   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.     *
 *                                                                      *
 ************************************************************************/
/* ------------------------------------------------------------------ */
/* | Copyright Unpublished, MIPS Computer Systems, Inc.  All Rights | */
/* | Reserved.  This software contains proprietary and confidential | */
/* | information of MIPS and its suppliers.  Use, disclosure or     | */
/* | reproduction is prohibited without the prior express written   | */
/* | consent of MIPS.                                               | */
/* ------------------------------------------------------------------ */
/* $Header: sh.exp.c,v 1.4 87/04/15 08:56:53 dce Exp $ */

#include "sh.h"

/*
 * C shell
 *
 * Modification History
 *
 * 001 - Bob Fontaine - Fri Jun 22 09:53:01 EDT 1990
 *	 changed call to csh internal printf routine to csh_printf to avoid
 *	 confusion with stdio printf.
 */


#define IGNORE	1	/* in ignore, it means to ignore value, just parse */
#define NOGLOB	2	/* in ignore, it means not to globone */

#define	ADDOP	1
#define	MULOP	2
#define	EQOP	4
#define	RELOP	8
#define	RESTOP	16
#define	ANYOP	31

#define	EQEQ	1
#define	GTR	2
#define	LSS	4
#define	NOTEQ	6
#define EQMATCH 7
#define NOTEQMATCH 8

exp(vp)
	register char ***vp;
{

	return (exp0(vp, 0));
}

exp0(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register int p1 = exp1(vp, ignore);
	
#ifdef EDEBUG
	etraci("exp0 p1", p1, vp);
#endif
	if (**vp && eq(**vp, "||")) {
		register int p2;

		(*vp)++;
		p2 = exp0(vp, (ignore&IGNORE) || p1);
#ifdef EDEBUG
		etraci("exp0 p2", p2, vp);
#endif
		return (p1 || p2);
	}
	return (p1);
}

exp1(vp, ignore)
	register char ***vp;
{
	register int p1 = exp2(vp, ignore);

#ifdef EDEBUG
	etraci("exp1 p1", p1, vp);
#endif
	if (**vp && eq(**vp, "&&")) {
		register int p2;

		(*vp)++;
		p2 = exp1(vp, (ignore&IGNORE) || !p1);
#ifdef EDEBUG
		etraci("exp1 p2", p2, vp);
#endif
		return (p1 && p2);
	}
	return (p1);
}

exp2(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register int p1 = exp2a(vp, ignore);

#ifdef EDEBUG
	etraci("exp3 p1", p1, vp);
#endif
	if (**vp && eq(**vp, "|")) {
		register int p2;

		(*vp)++;
		p2 = exp2(vp, ignore);
#ifdef EDEBUG
		etraci("exp3 p2", p2, vp);
#endif
		return (p1 | p2);
	}
	return (p1);
}

exp2a(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register int p1 = exp2b(vp, ignore);

#ifdef EDEBUG
	etraci("exp2a p1", p1, vp);
#endif
	if (**vp && eq(**vp, "^")) {
		register int p2;

		(*vp)++;
		p2 = exp2a(vp, ignore);
#ifdef EDEBUG
		etraci("exp2a p2", p2, vp);
#endif
		return (p1 ^ p2);
	}
	return (p1);
}

exp2b(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register int p1 = exp2c(vp, ignore);

#ifdef EDEBUG
	etraci("exp2b p1", p1, vp);
#endif
	if (**vp && eq(**vp, "&")) {
		register int p2;

		(*vp)++;
		p2 = exp2b(vp, ignore);
#ifdef EDEBUG
		etraci("exp2b p2", p2, vp);
#endif
		return (p1 & p2);
	}
	return (p1);
}

exp2c(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register char *p1 = exp3(vp, ignore);
	register char *p2;
	register int i;

#ifdef EDEBUG
	etracc("exp2c p1", p1, vp);
#endif
	if (i = isa(**vp, EQOP)) {
		(*vp)++;
		if (i == EQMATCH || i == NOTEQMATCH)
			ignore |= NOGLOB;
		p2 = exp3(vp, ignore);
#ifdef EDEBUG
		etracc("exp2c p2", p2, vp);
#endif
		if (!(ignore&IGNORE)) switch (i) {

		case EQEQ:
			i = eq(p1, p2);
			break;

		case NOTEQ:
			i = !eq(p1, p2);
			break;

		case EQMATCH:
			i = Gmatch(p1, p2);
			break;

		case NOTEQMATCH:
			i = !Gmatch(p1, p2);
			break;
		}
		xfree(p1), xfree(p2);
		return (i);
	}
	i = egetn(p1);
	xfree(p1);
	return (i);
}

char *
exp3(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register char *p1, *p2;
	register int i;

	p1 = exp3a(vp, ignore);
#ifdef EDEBUG
	etracc("exp3 p1", p1, vp);
#endif
	if (i = isa(**vp, RELOP)) {
		(*vp)++;
		if (**vp && eq(**vp, "="))
			i |= 1, (*vp)++;
		p2 = exp3(vp, ignore);
#ifdef EDEBUG
		etracc("exp3 p2", p2, vp);
#endif
		if (!(ignore&IGNORE)) switch (i) {

		case GTR:
			i = egetn(p1) > egetn(p2);
			break;

		case GTR|1:
			i = egetn(p1) >= egetn(p2);
			break;

		case LSS:
			i = egetn(p1) < egetn(p2);
			break;

		case LSS|1:
			i = egetn(p1) <= egetn(p2);
			break;
		}
		xfree(p1), xfree(p2);
		return (putn(i));
	}
	return (p1);
}

char *
exp3a(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register char *p1, *p2, *op;
	register int i;

	p1 = exp4(vp, ignore);
#ifdef EDEBUG
	etracc("exp3a p1", p1, vp);
#endif
	op = **vp;
	if (op && any(op[0], "<>") && op[0] == op[1]) {
		(*vp)++;
		p2 = exp3a(vp, ignore);
#ifdef EDEBUG
		etracc("exp3a p2", p2, vp);
#endif
		if (op[0] == '<')
			i = egetn(p1) << egetn(p2);
		else
			i = egetn(p1) >> egetn(p2);
		xfree(p1), xfree(p2);
		return (putn(i));
	}
	return (p1);
}

char *
exp4(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register char *p1, *p2;
	register int i = 0;

	p1 = exp5(vp, ignore);
#ifdef EDEBUG
	etracc("exp4 p1", p1, vp);
#endif
	if (isa(**vp, ADDOP)) {
		register char *op = *(*vp)++;

		p2 = exp4(vp, ignore);
#ifdef EDEBUG
		etracc("exp4 p2", p2, vp);
#endif
		if (!(ignore&IGNORE)) switch (op[0]) {

		case '+':
			i = egetn(p1) + egetn(p2);
			break;

		case '-':
			i = egetn(p1) - egetn(p2);
			break;
		}
		xfree(p1), xfree(p2);
		return (putn(i));
	}
	return (p1);
}

char *
exp5(vp, ignore)
	register char ***vp;
	bool ignore;
{
	register char *p1, *p2;
	register int i = 0;

	p1 = exp6(vp, ignore);
#ifdef EDEBUG
	etracc("exp5 p1", p1, vp);
#endif
	if (isa(**vp, MULOP)) {
		register char *op = *(*vp)++;

		p2 = exp5(vp, ignore);
#ifdef EDEBUG
		etracc("exp5 p2", p2, vp);
#endif
		if (!(ignore&IGNORE)) switch (op[0]) {

		case '*':
			i = egetn(p1) * egetn(p2);
			break;

		case '/':
			i = egetn(p2);
			if (i == 0)
				error("Divide by 0");
			i = egetn(p1) / i;
			break;

		case '%':
			i = egetn(p2);
			if (i == 0)
				error("Mod by 0");
			i = egetn(p1) % i;
			break;
		}
		xfree(p1), xfree(p2);
		return (putn(i));
	}
	return (p1);
}

char *
exp6(vp, ignore)
	register char ***vp;
{
	int ccode, i;
	register char *cp, *dp, *ep;

	if (**vp == 0)
		bferr("Expression syntax");
	if (eq(**vp, "!")) {
		(*vp)++;
		cp = exp6(vp, ignore);
#ifdef EDEBUG
		etracc("exp6 ! cp", cp, vp);
#endif
		i = egetn(cp);
		xfree(cp);
		return (putn(!i));
	}
	if (eq(**vp, "~")) {
		(*vp)++;
		cp = exp6(vp, ignore);
#ifdef EDEBUG
		etracc("exp6 ~ cp", cp, vp);
#endif
		i = egetn(cp);
		xfree(cp);
		return (putn(~i));
	}
	if (eq(**vp, "(")) {
		(*vp)++;
		ccode = exp0(vp, ignore);
#ifdef EDEBUG
		etraci("exp6 () ccode", ccode, vp);
#endif
		if (*vp == 0 || **vp == 0 || ***vp != ')')
			bferr("Expression syntax");
		(*vp)++;
		return (putn(ccode));
	}
	if (eq(**vp, "{")) {
		register char **v;
		struct command faket;
		char *fakecom[2];

		faket.t_dtyp = TCOM;
		faket.t_dflg = 0;
		faket.t_dcar = faket.t_dcdr = faket.t_dspr = (struct command *)0;
		faket.t_dcom = fakecom;
		fakecom[0] = "{ ... }";
		fakecom[1] = NOSTR;
		(*vp)++;
		v = *vp;
		for (;;) {
			if (!**vp)
				bferr("Missing }");
			if (eq(*(*vp)++, "}"))
				break;
		}
		if (ignore&IGNORE)
			return ("");
		psavejob();
		if (pfork(&faket, -1) == 0) {
			*--(*vp) = 0;
			evalav(v);
			exitstat();
		}
		pwait();
		prestjob();
#ifdef EDEBUG
		etraci("exp6 {} status", egetn(value("status")), vp);
#endif
		return (putn(egetn(value("status")) == 0));
	}
	if (isa(**vp, ANYOP))
		return ("");
	cp = *(*vp)++;
	if (*cp == '-' && any(cp[1], "erwxfdzo")) {
		struct stat stb;

/*
 * The check used to be for ANYOP, but that isn't correct since it caused
 * the expression ( -d / ) to say 'Missing file name'. RESTOP is somewhat
 * better, but not perfect. This -[rwxd...] stuff is for the birds anyway.
 * We should be using Lisp syntax, functions like isdir(name), or something
 * equally clear instead of all of this ambiuous junk.
 */

		if (isa(**vp, RESTOP))
			bferr("Missing file name");
		dp = *(*vp)++;
		if (ignore&IGNORE)
			return ("");
		ep = globone(dp);
		switch (cp[1]) {

		case 'r':
			i = !access(ep, 4);
			break;

		case 'w':
			i = !access(ep, 2);
			break;

		case 'x':
			i = !access(ep, 1);
			break;

		default:
			if (stat(ep, &stb)) {
				xfree(ep);
				return ("0");
			}
			switch (cp[1]) {

			case 'f':
				i = (stb.st_mode & S_IFMT) == S_IFREG;
				break;

			case 'd':
				i = (stb.st_mode & S_IFMT) == S_IFDIR;
				break;

			case 'z':
				i = stb.st_size == 0;
				break;

			case 'e':
				i = 1;
				break;

			case 'o':
				i = stb.st_uid == uid;
				break;
			}
		}
#ifdef EDEBUG
		etraci("exp6 -? i", i, vp);
#endif
		xfree(ep);
		return (putn(i));
	}
#ifdef EDEBUG
	etracc("exp6 default", cp, vp);
#endif
	return (ignore&NOGLOB ? savestr(cp) : globone(cp));
}

evalav(v)
	register char **v;
{
	struct wordent paraml;
	register struct wordent *hp = &paraml;
	struct command *t;
	register struct wordent *wdp = hp;
	
	set("status", "0");
	hp->prev = hp->next = hp;
	hp->word = "";
	while (*v) {
		register struct wordent *new = (struct wordent *) calloc(1, sizeof *wdp);

		new->prev = wdp;
		new->next = hp;
		wdp->next = new;
		wdp = new;
		wdp->word = savestr(*v++);
	}
	hp->prev = wdp;
	alias(&paraml);
	t = syntax(paraml.next, &paraml, 0);
	if (err)
		error(err);
	execute(t, -1);
	freelex(&paraml), freesyn(t);
}

isa(cp, what)
	register char *cp;
	register int what;
{

	if (cp == 0)
		return ((what & RESTOP) != 0);
	if (cp[1] == 0) {
		if (what & ADDOP && (*cp == '+' || *cp == '-'))
			return (1);
		if (what & MULOP && (*cp == '*' || *cp == '/' || *cp == '%'))
			return (1);
		if (what & RESTOP && (*cp == '(' || *cp == ')' || *cp == '!' ||
				      *cp == '~' || *cp == '^' || *cp == '"'))
			return (1);
	} else if (cp[2] == 0) {
		if (what & RESTOP) {
			if (cp[0] == '|' && cp[1] == '&')
				return (1);
			if (cp[0] == '<' && cp[1] == '<')
				return (1);
			if (cp[0] == '>' && cp[1] == '>')
				return (1);
		}
		if (what & EQOP) {
			if (cp[0] == '=') {
				if (cp[1] == '=')
					return (EQEQ);
				if (cp[1] == '~')
					return (EQMATCH);
			} else if (cp[0] == '!') {
				if (cp[1] == '=')
					return (NOTEQ);
				if (cp[1] == '~')
					return (NOTEQMATCH);
			}
		}
	}
	if (what & RELOP) {
		if (*cp == '<')
			return (LSS);
		if (*cp == '>')
			return (GTR);
	}
	return (0);
}

egetn(cp)
	register char *cp;
{

	if (*cp && *cp != '-' && !digit(*cp))
		bferr("Expression syntax");
	return (getn(cp));
}

/* Phew! */

#ifdef EDEBUG
etraci(str, i, vp)
	char *str;
	int i;
	char ***vp;
{

	csh_printf("%s=%d\t", str, i);		/*  001 RNF  */
	blkpr(*vp);
	csh_printf("\n");			/*  001 RNF  */
}

etracc(str, cp, vp)
	char *str, *cp;
	char ***vp;
{

	csh_printf("%s=%s\t", str, cp);		/*  001 RNF  */
	blkpr(*vp);
	csh_printf("\n");			/*  001 RNF  */
}
#endif