dol.c

早期freebsd实现

/*-
 * Copyright (c) 1980, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)dol.c	8.1 (Berkeley) 5/31/93";
#endif /* not lint */

#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if __STDC__
# include <stdarg.h>
#else
# include <varargs.h>
#endif

#include "csh.h"
#include "extern.h"

/*
 * These routines perform variable substitution and quoting via ' and ".
 * To this point these constructs have been preserved in the divided
 * input words.  Here we expand variables and turn quoting via ' and " into
 * QUOTE bits on characters (which prevent further interpretation).
 * If the `:q' modifier was applied during history expansion, then
 * some QUOTEing may have occurred already, so we dont "trim()" here.
 */

static int Dpeekc, Dpeekrd;	/* Peeks for DgetC and Dreadc */
static Char *Dcp, **Dvp;	/* Input vector for Dreadc */

#define	DEOF	-1

#define	unDgetC(c)	Dpeekc = c

#define QUOTES		(_QF|_QB|_ESC)	/* \ ' " ` */

/*
 * The following variables give the information about the current
 * $ expansion, recording the current word position, the remaining
 * words within this expansion, the count of remaining words, and the
 * information about any : modifier which is being applied.
 */
#define MAXWLEN (BUFSIZ - 4)
#define MAXMOD MAXWLEN		/* This cannot overflow	*/
static Char *dolp;		/* Remaining chars from this word */
static Char **dolnxt;		/* Further words */
static int dolcnt;		/* Count of further words */
static Char dolmod[MAXMOD];	/* : modifier character */
static int dolnmod;		/* Number of modifiers */
static int dolmcnt;		/* :gx -> 10000, else 1 */
static int dolwcnt;		/* :wx -> 10000, else 1 */

static void	 Dfix2 __P((Char **));
static Char	*Dpack __P((Char *, Char *));
static int	 Dword __P((void));
static void	 dolerror __P((Char *));
static int	 DgetC __P((int));
static void	 Dgetdol __P((void));
static void	 fixDolMod __P((void));
static void	 setDolp __P((Char *));
static void	 unDredc __P((int));
static int	 Dredc __P((void));
static void	 Dtestq __P((int));


/*
 * Fix up the $ expansions and quotations in the
 * argument list to command t.
 */
void
Dfix(t)
    register struct command *t;
{
    register Char **pp;
    register Char *p;

    if (noexec)
	return;
    /* Note that t_dcom isn't trimmed thus !...:q's aren't lost */
    for (pp = t->t_dcom; (p = *pp++) != NULL;)
	for (; *p; p++) {
	    if (cmap(*p, _DOL | QUOTES)) {	/* $, \, ', ", ` */
		Dfix2(t->t_dcom);	/* found one */
		blkfree(t->t_dcom);
		t->t_dcom = gargv;
		gargv = 0;
		return;
	    }
	}
}

/*
 * $ substitute one word, for i/o redirection
 */
Char   *
Dfix1(cp)
    register Char *cp;
{
    Char   *Dv[2];

    if (noexec)
	return (0);
    Dv[0] = cp;
    Dv[1] = NULL;
    Dfix2(Dv);
    if (gargc != 1) {
	setname(vis_str(cp));
	stderror(ERR_NAME | ERR_AMBIG);
    }
    cp = Strsave(gargv[0]);
    blkfree(gargv), gargv = 0;
    return (cp);
}

/*
 * Subroutine to do actual fixing after state initialization.
 */
static void
Dfix2(v)
    Char  **v;
{
    ginit();			/* Initialize glob's area pointers */
    Dvp = v;
    Dcp = STRNULL;		/* Setup input vector for Dreadc */
    unDgetC(0);
    unDredc(0);			/* Clear out any old peeks (at error) */
    dolp = 0;
    dolcnt = 0;			/* Clear out residual $ expands (...) */
    while (Dword())
	continue;
}

/*
 * Pack up more characters in this word
 */
static Char *
Dpack(wbuf, wp)
    Char   *wbuf, *wp;
{
    register int c;
    register int i = MAXWLEN - (wp - wbuf);

    for (;;) {
	c = DgetC(DODOL);
	if (c == '\\') {
	    c = DgetC(0);
	    if (c == DEOF) {
		unDredc(c);
		*wp = 0;
		Gcat(STRNULL, wbuf);
		return (NULL);
	    }
	    if (c == '\n')
		c = ' ';
	    else
		c |= QUOTE;
	}
	if (c == DEOF) {
	    unDredc(c);
	    *wp = 0;
	    Gcat(STRNULL, wbuf);
	    return (NULL);
	}
	if (cmap(c, _SP | _NL | _QF | _QB)) {	/* sp \t\n'"` */
	    unDgetC(c);
	    if (cmap(c, QUOTES))
		return (wp);
	    *wp++ = 0;
	    Gcat(STRNULL, wbuf);
	    return (NULL);
	}
	if (--i <= 0)
	    stderror(ERR_WTOOLONG);
	*wp++ = c;
    }
}

/*
 * Get a word.  This routine is analogous to the routine
 * word() in sh.lex.c for the main lexical input.  One difference
 * here is that we don't get a newline to terminate our expansion.
 * Rather, DgetC will return a DEOF when we hit the end-of-input.
 */
static int
Dword()
{
    register int c, c1;
    Char    wbuf[BUFSIZ];
    register Char *wp = wbuf;
    register int i = MAXWLEN;
    register bool dolflg;
    bool    sofar = 0, done = 0;

    while (!done) {
	done = 1;
	c = DgetC(DODOL);
	switch (c) {

	case DEOF:
	    if (sofar == 0)
		return (0);
	    /* finish this word and catch the code above the next time */
	    unDredc(c);
	    /* fall into ... */

	case '\n':
	    *wp = 0;
	    Gcat(STRNULL, wbuf);
	    return (1);

	case ' ':
	case '\t':
	    done = 0;
	    break;

	case '`':
	    /* We preserve ` quotations which are done yet later */
	    *wp++ = c, --i;
	case '\'':
	case '"':
	    /*
	     * Note that DgetC never returns a QUOTES character from an
	     * expansion, so only true input quotes will get us here or out.
	     */
	    c1 = c;
	    dolflg = c1 == '"' ? DODOL : 0;
	    for (;;) {
		c = DgetC(dolflg);
		if (c == c1)
		    break;
		if (c == '\n' || c == DEOF)
		    stderror(ERR_UNMATCHED, c1);
		if ((c & (QUOTE | TRIM)) == ('\n' | QUOTE))
		    --wp, ++i;
		if (--i <= 0)
		    stderror(ERR_WTOOLONG);
		switch (c1) {

		case '"':
		    /*
		     * Leave any `s alone for later. Other chars are all
		     * quoted, thus `...` can tell it was within "...".
		     */
		    *wp++ = c == '`' ? '`' : c | QUOTE;
		    break;

		case '\'':
		    /* Prevent all further interpretation */
		    *wp++ = c | QUOTE;
		    break;

		case '`':
		    /* Leave all text alone for later */
		    *wp++ = c;
		    break;

		default:
		    break;
		}
	    }
	    if (c1 == '`')
		*wp++ = '`' /* i--; eliminated */;
	    sofar = 1;
	    if ((wp = Dpack(wbuf, wp)) == NULL)
		return (1);
	    else {
		i = MAXWLEN - (wp - wbuf);
		done = 0;
	    }
	    break;

	case '\\':
	    c = DgetC(0);	/* No $ subst! */
	    if (c == '\n' || c == DEOF) {
		done = 0;
		break;
	    }
	    c |= QUOTE;
	    break;

	default:
	    break;
	}
	if (done) {
	    unDgetC(c);
	    sofar = 1;
	    if ((wp = Dpack(wbuf, wp)) == NULL)
		return (1);
	    else {
		i = MAXWLEN - (wp - wbuf);
		done = 0;
	    }
	}
    }
    /* Really NOTREACHED */
    return (0);
}


/*
 * Get a character, performing $ substitution unless flag is 0.
 * Any QUOTES character which is returned from a $ expansion is
 * QUOTEd so that it will not be recognized above.
 */
static int
DgetC(flag)
    register int flag;
{
    register int c;

top:
    if ((c = Dpeekc) != '\0') {
	Dpeekc = 0;
	return (c);
    }
    if (lap) {
	c = *lap++ & (QUOTE | TRIM);
	if (c == 0) {
	    lap = 0;
	    goto top;
	}
quotspec:
	if (cmap(c, QUOTES))
	    return (c | QUOTE);
	return (c);
    }
    if (dolp) {
	if ((c = *dolp++ & (QUOTE | TRIM)) != '\0')
	    goto quotspec;
	if (dolcnt > 0) {
	    setDolp(*dolnxt++);
	    --dolcnt;
	    return (' ');
	}
	dolp = 0;
    }
    if (dolcnt > 0) {
	setDolp(*dolnxt++);
	--dolcnt;
	goto top;
    }
    c = Dredc();
    if (c == '$' && flag) {
	Dgetdol();
	goto top;
    }
    return (c);
}

static Char *nulvec[] = {0};
static struct varent nulargv = {nulvec, STRargv, { NULL, NULL, NULL }, 0};

static void
dolerror(s)
    Char   *s;
{
    setname(vis_str(s));
    stderror(ERR_NAME | ERR_RANGE);
}

/*
 * Handle the multitudinous $ expansion forms.
 * Ugh.
 */
static void
Dgetdol()
{
    register Char *np;
    register struct varent *vp = NULL;
    Char    name[4 * MAXVARLEN + 1];
    int     c, sc;
    int     subscr = 0, lwb = 1, upb = 0;
    bool    dimen = 0, bitset = 0;
    char    tnp;
    Char    wbuf[BUFSIZ];
    static Char *dolbang = NULL;

    dolnmod = dolmcnt = dolwcnt = 0;
    c = sc = DgetC(0);
    if (c == '{')
	c = DgetC(0);		/* sc is { to take } later */
    if ((c & TRIM) == '#')
	dimen++, c = DgetC(0);	/* $# takes dimension */
    else if (c == '?')
	bitset++, c = DgetC(0);	/* $? tests existence */
    switch (c) {

    case '!':
	if (dimen || bitset)
	    stderror(ERR_SYNTAX);
	if (backpid != 0) {
	    if (dolbang) 
		xfree((ptr_t) dolbang);
	    setDolp(dolbang = putn(backpid));
	}
	goto eatbrac;

    case '$':
	if (dimen || bitset)
	    stderror(ERR_SYNTAX);
	setDolp(doldol);
	goto eatbrac;

    case '<' | QUOTE:
	if (bitset)
	    stderror(ERR_NOTALLOWED, "$?<");
	if (dimen)
	    stderror(ERR_NOTALLOWED, "$?#");
	for (np = wbuf; read(OLDSTD, &tnp, 1) == 1; np++) {
	    *np = (unsigned char) tnp;
	    if (np >= &wbuf[BUFSIZ - 1])
		stderror(ERR_LTOOLONG);
	    if (tnp == '\n')
		break;
	}
	*np = 0;
	/*
	 * KLUDGE: dolmod is set here because it will cause setDolp to call
	 * domod and thus to copy wbuf. Otherwise setDolp would use it
	 * directly. If we saved it ourselves, no one would know when to free
	 * it. The actual function of the 'q' causes filename expansion not to
	 * be done on the interpolated value.
	 */
	dolmod[dolnmod++] = 'q';
	dolmcnt = 10000;
	setDolp(wbuf);
	goto eatbrac;

    case DEOF:
    case '\n':
	stderror(ERR_SYNTAX);
	/* NOTREACHED */
	break;

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

    default:
	np = name;
	if (Isdigit(c)) {
	    if (dimen)
		stderror(ERR_NOTALLOWED, "$#<num>");
	    subscr = 0;
	    do {
		subscr = subscr * 10 + c - '0';
		c = DgetC(0);
	    } while (Isdigit(c));
	    unDredc(c);
	    if (subscr < 0) {
		dolerror(vp->v_name);
		return;
	    }
	    if (subscr == 0) {
		if (bitset) {
		    dolp = ffile ? STR1 : STR0;
		    goto eatbrac;