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dol.c revision 1.18
      1 /* $NetBSD: dol.c,v 1.18 2002/01/30 07:02:01 itohy Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 1980, 1991, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)dol.c	8.1 (Berkeley) 5/31/93";
     40 #else
     41 __RCSID("$NetBSD: dol.c,v 1.18 2002/01/30 07:02:01 itohy Exp $");
     42 #endif
     43 #endif /* not lint */
     44 
     45 #include <sys/types.h>
     46 
     47 #include <errno.h>
     48 #include <fcntl.h>
     49 #include <stdlib.h>
     50 #include <string.h>
     51 #include <unistd.h>
     52 
     53 #if __STDC__
     54 # include <stdarg.h>
     55 #else
     56 # include <varargs.h>
     57 #endif
     58 
     59 #include "csh.h"
     60 #include "extern.h"
     61 
     62 /*
     63  * These routines perform variable substitution and quoting via ' and ".
     64  * To this point these constructs have been preserved in the divided
     65  * input words.  Here we expand variables and turn quoting via ' and " into
     66  * QUOTE bits on characters (which prevent further interpretation).
     67  * If the `:q' modifier was applied during history expansion, then
     68  * some QUOTEing may have occurred already, so we dont "trim()" here.
     69  */
     70 
     71 static int Dpeekc, Dpeekrd;	/* Peeks for DgetC and Dreadc */
     72 static Char *Dcp, **Dvp;	/* Input vector for Dreadc */
     73 
     74 #define	DEOF -1
     75 #define	unDgetC(c) Dpeekc = c
     76 #define QUOTES (_QF|_QB|_ESC)	/* \ ' " ` */
     77 
     78 /*
     79  * The following variables give the information about the current
     80  * $ expansion, recording the current word position, the remaining
     81  * words within this expansion, the count of remaining words, and the
     82  * information about any : modifier which is being applied.
     83  */
     84 #define MAXWLEN (BUFSIZE - 4)
     85 #define MAXMOD MAXWLEN		/* This cannot overflow	*/
     86 static Char dolmod[MAXMOD];	/* : modifier character */
     87 static Char *dolp;		/* Remaining chars from this word */
     88 static Char **dolnxt;		/* Further words */
     89 static int dolcnt;		/* Count of further words */
     90 static int dolnmod;		/* Number of modifiers */
     91 static int dolmcnt;		/* :gx -> 10000, else 1 */
     92 static int dolwcnt;		/* :wx -> 10000, else 1 */
     93 
     94 static void Dfix2(Char **);
     95 static Char *Dpack(Char *, Char *);
     96 static int Dword(void);
     97 static void dolerror(Char *);
     98 static int DgetC(int);
     99 static void Dgetdol(void);
    100 static void fixDolMod(void);
    101 static void setDolp(Char *);
    102 static void unDredc(int);
    103 static int Dredc(void);
    104 static void Dtestq(int);
    105 
    106 
    107 /*
    108  * Fix up the $ expansions and quotations in the
    109  * argument list to command t.
    110  */
    111 void
    112 Dfix(struct command *t)
    113 {
    114     Char *p, **pp;
    115 
    116     if (noexec)
    117 	return;
    118     /* Note that t_dcom isn't trimmed thus !...:q's aren't lost */
    119     for (pp = t->t_dcom; (p = *pp++) != NULL;)
    120 	for (; *p; p++) {
    121 	    if (cmap(*p, _DOL | QUOTES)) {	/* $, \, ', ", ` */
    122 		Dfix2(t->t_dcom);	/* found one */
    123 		blkfree(t->t_dcom);
    124 		t->t_dcom = gargv;
    125 		gargv = 0;
    126 		return;
    127 	    }
    128 	}
    129 }
    130 
    131 /*
    132  * $ substitute one word, for i/o redirection
    133  */
    134 Char *
    135 Dfix1(Char *cp)
    136 {
    137     Char *Dv[2];
    138 
    139     if (noexec)
    140 	return (0);
    141     Dv[0] = cp;
    142     Dv[1] = NULL;
    143     Dfix2(Dv);
    144     if (gargc != 1) {
    145 	setname(vis_str(cp));
    146 	stderror(ERR_NAME | ERR_AMBIG);
    147     }
    148     cp = Strsave(gargv[0]);
    149     blkfree(gargv), gargv = 0;
    150     return (cp);
    151 }
    152 
    153 /*
    154  * Subroutine to do actual fixing after state initialization.
    155  */
    156 static void
    157 Dfix2(Char **v)
    158 {
    159     ginit();			/* Initialize glob's area pointers */
    160     Dvp = v;
    161     Dcp = STRNULL;		/* Setup input vector for Dreadc */
    162     unDgetC(0);
    163     unDredc(0);			/* Clear out any old peeks (at error) */
    164     dolp = 0;
    165     dolcnt = 0;			/* Clear out residual $ expands (...) */
    166     while (Dword())
    167 	continue;
    168 }
    169 
    170 /*
    171  * Pack up more characters in this word
    172  */
    173 static Char *
    174 Dpack(Char *wbuf, Char *wp)
    175 {
    176     int c, i;
    177 
    178     i = MAXWLEN - (wp - wbuf);
    179     for (;;) {
    180 	c = DgetC(DODOL);
    181 	if (c == '\\') {
    182 	    c = DgetC(0);
    183 	    if (c == DEOF) {
    184 		unDredc(c);
    185 		*wp = 0;
    186 		Gcat(STRNULL, wbuf);
    187 		return (NULL);
    188 	    }
    189 	    if (c == '\n')
    190 		c = ' ';
    191 	    else
    192 		c |= QUOTE;
    193 	}
    194 	if (c == DEOF) {
    195 	    unDredc(c);
    196 	    *wp = 0;
    197 	    Gcat(STRNULL, wbuf);
    198 	    return (NULL);
    199 	}
    200 	if (cmap(c, _SP | _NL | _QF | _QB)) {	/* sp \t\n'"` */
    201 	    unDgetC(c);
    202 	    if (cmap(c, QUOTES))
    203 		return (wp);
    204 	    *wp++ = 0;
    205 	    Gcat(STRNULL, wbuf);
    206 	    return (NULL);
    207 	}
    208 	if (--i <= 0)
    209 	    stderror(ERR_WTOOLONG);
    210 	*wp++ = c;
    211     }
    212 }
    213 
    214 /*
    215  * Get a word.  This routine is analogous to the routine
    216  * word() in sh.lex.c for the main lexical input.  One difference
    217  * here is that we don't get a newline to terminate our expansion.
    218  * Rather, DgetC will return a DEOF when we hit the end-of-input.
    219  */
    220 static int
    221 Dword(void)
    222 {
    223     Char wbuf[BUFSIZE], *wp;
    224     int c, c1, i;
    225     bool dolflg, done, sofar;
    226 
    227     done = 0;
    228     i = MAXWLEN;
    229     sofar = 0;
    230     wp = wbuf;
    231 
    232     while (!done) {
    233 	done = 1;
    234 	c = DgetC(DODOL);
    235 	switch (c) {
    236 	case DEOF:
    237 	    if (sofar == 0)
    238 		return (0);
    239 	    /* finish this word and catch the code above the next time */
    240 	    unDredc(c);
    241 	    /* FALLTHROUGH */
    242 	case '\n':
    243 	    *wp = 0;
    244 	    Gcat(STRNULL, wbuf);
    245 	    return (1);
    246 	case ' ':
    247 	case '\t':
    248 	    done = 0;
    249 	    break;
    250 	case '`':
    251 	    /* We preserve ` quotations which are done yet later */
    252 	    *wp++ = c, --i;
    253 	    /* FALLTHROUGH */
    254 	case '\'':
    255 	case '"':
    256 	    /*
    257 	     * Note that DgetC never returns a QUOTES character from an
    258 	     * expansion, so only true input quotes will get us here or out.
    259 	     */
    260 	    c1 = c;
    261 	    dolflg = c1 == '"' ? DODOL : 0;
    262 	    for (;;) {
    263 		c = DgetC(dolflg);
    264 		if (c == c1)
    265 		    break;
    266 		if (c == '\n' || c == DEOF)
    267 		    stderror(ERR_UNMATCHED, c1);
    268 		if ((c & (QUOTE | TRIM)) == ('\n' | QUOTE))
    269 		    --wp, ++i;
    270 		if (--i <= 0)
    271 		    stderror(ERR_WTOOLONG);
    272 		switch (c1) {
    273 		case '"':
    274 		    /*
    275 		     * Leave any `s alone for later. Other chars are all
    276 		     * quoted, thus `...` can tell it was within "...".
    277 		     */
    278 		    *wp++ = c == '`' ? '`' : c | QUOTE;
    279 		    break;
    280 		case '\'':
    281 		    /* Prevent all further interpretation */
    282 		    *wp++ = c | QUOTE;
    283 		    break;
    284 		case '`':
    285 		    /* Leave all text alone for later */
    286 		    *wp++ = c;
    287 		    break;
    288 		default:
    289 		    break;
    290 		}
    291 	    }
    292 	    if (c1 == '`')
    293 		*wp++ = '`' /* i--; eliminated */;
    294 	    sofar = 1;
    295 	    if ((wp = Dpack(wbuf, wp)) == NULL)
    296 		return (1);
    297 	    else {
    298 		i = MAXWLEN - (wp - wbuf);
    299 		done = 0;
    300 	    }
    301 	    break;
    302 	case '\\':
    303 	    c = DgetC(0);	/* No $ subst! */
    304 	    if (c == '\n' || c == DEOF) {
    305 		done = 0;
    306 		break;
    307 	    }
    308 	    c |= QUOTE;
    309 	    break;
    310 	default:
    311 	    break;
    312 	}
    313 	if (done) {
    314 	    unDgetC(c);
    315 	    sofar = 1;
    316 	    if ((wp = Dpack(wbuf, wp)) == NULL)
    317 		return (1);
    318 	    else {
    319 		i = MAXWLEN - (wp - wbuf);
    320 		done = 0;
    321 	    }
    322 	}
    323     }
    324     /* Really NOTREACHED */
    325     return (0);
    326 }
    327 
    328 
    329 /*
    330  * Get a character, performing $ substitution unless flag is 0.
    331  * Any QUOTES character which is returned from a $ expansion is
    332  * QUOTEd so that it will not be recognized above.
    333  */
    334 static int
    335 DgetC(int flag)
    336 {
    337     int c;
    338 top:
    339     if ((c = Dpeekc) != '\0') {
    340 	Dpeekc = 0;
    341 	return (c);
    342     }
    343     if (lap) {
    344 	c = *lap++ & (QUOTE | TRIM);
    345 	if (c == 0) {
    346 	    lap = 0;
    347 	    goto top;
    348 	}
    349 quotspec:
    350 	if (cmap(c, QUOTES))
    351 	    return (c | QUOTE);
    352 	return (c);
    353     }
    354     if (dolp) {
    355 	if ((c = *dolp++ & (QUOTE | TRIM)) != '\0')
    356 	    goto quotspec;
    357 	if (dolcnt > 0) {
    358 	    setDolp(*dolnxt++);
    359 	    --dolcnt;
    360 	    return (' ');
    361 	}
    362 	dolp = 0;
    363     }
    364     if (dolcnt > 0) {
    365 	setDolp(*dolnxt++);
    366 	--dolcnt;
    367 	goto top;
    368     }
    369     c = Dredc();
    370     if (c == '$' && flag) {
    371 	Dgetdol();
    372 	goto top;
    373     }
    374     return (c);
    375 }
    376 
    377 static Char *nulvec[] = {0};
    378 static struct varent nulargv = {nulvec, STRargv, { NULL, NULL, NULL }, 0};
    379 
    380 static void
    381 dolerror(Char *s)
    382 {
    383     setname(vis_str(s));
    384     stderror(ERR_NAME | ERR_RANGE);
    385     /* NOTREACHED */
    386 }
    387 
    388 /*
    389  * Handle the multitudinous $ expansion forms.
    390  * Ugh.
    391  */
    392 static void
    393 Dgetdol(void)
    394 {
    395     static Char *dolbang = NULL;
    396     Char name[4*MAXVARLEN+1];
    397     Char wbuf[BUFSIZE];
    398     struct varent *vp;
    399     Char *np;
    400     int c, lwb, sc, subscr, upb;
    401     bool dimen, bitset;
    402     char tnp;
    403 
    404     bitset = 0;
    405     dimen = 0;
    406     lwb = 1;
    407     upb = 0;
    408     subscr = 0;
    409     vp = NULL;
    410 
    411     dolnmod = dolmcnt = dolwcnt = 0;
    412     c = sc = DgetC(0);
    413     if (c == '{')
    414 	c = DgetC(0);		/* sc is { to take } later */
    415     if ((c & TRIM) == '#')
    416 	dimen++, c = DgetC(0);	/* $# takes dimension */
    417     else if (c == '?')
    418 	bitset++, c = DgetC(0);	/* $? tests existence */
    419     switch (c) {
    420     case '!':
    421 	if (dimen || bitset)
    422 	    stderror(ERR_SYNTAX);
    423 	if (backpid != 0) {
    424 	    if (dolbang)
    425 		xfree((ptr_t)dolbang);
    426 	    setDolp(dolbang = putn(backpid));
    427 	}
    428 	goto eatbrac;
    429     case '$':
    430 	if (dimen || bitset)
    431 	    stderror(ERR_SYNTAX);
    432 	setDolp(doldol);
    433 	goto eatbrac;
    434     case '<' | QUOTE:
    435 	if (bitset)
    436 	    stderror(ERR_NOTALLOWED, "$?<");
    437 	if (dimen)
    438 	    stderror(ERR_NOTALLOWED, "$?#");
    439 	for (np = wbuf; read(OLDSTD, &tnp, 1) == 1; np++) {
    440 	    *np = (unsigned char)tnp;
    441 	    if (np >= &wbuf[BUFSIZE - 1])
    442 		stderror(ERR_LTOOLONG);
    443 	    if (tnp == '\n')
    444 		break;
    445 	}
    446 	*np = 0;
    447 	/*
    448 	 * KLUDGE: dolmod is set here because it will cause setDolp to call
    449 	 * domod and thus to copy wbuf. Otherwise setDolp would use it
    450 	 * directly. If we saved it ourselves, no one would know when to free
    451 	 * it. The actual function of the 'q' causes filename expansion not to
    452 	 * be done on the interpolated value.
    453 	 */
    454 	dolmod[dolnmod++] = 'q';
    455 	dolmcnt = 10000;
    456 	setDolp(wbuf);
    457 	goto eatbrac;
    458     case DEOF:
    459     case '\n':
    460 	stderror(ERR_SYNTAX);
    461 	/* NOTREACHED */
    462     case '*':
    463 	(void) Strcpy(name, STRargv);
    464 	vp = adrof(STRargv);
    465 	subscr = -1;		/* Prevent eating [...] */
    466 	break;
    467     default:
    468 	np = name;
    469 	if (Isdigit(c)) {
    470 	    if (dimen)
    471 		stderror(ERR_NOTALLOWED, "$#<num>");
    472 	    subscr = 0;
    473 	    do {
    474 		subscr = subscr * 10 + c - '0';
    475 		c = DgetC(0);
    476 	    } while (Isdigit(c));
    477 	    unDredc(c);
    478 	    if (subscr < 0) {
    479 		stderror(ERR_RANGE);
    480 		return;
    481 	    }
    482 	    if (subscr == 0) {
    483 		if (bitset) {
    484 		    dolp = ffile ? STR1 : STR0;
    485 		    goto eatbrac;
    486 		}
    487 		if (ffile == 0)
    488 		    stderror(ERR_DOLZERO);
    489 		fixDolMod();
    490 		setDolp(ffile);
    491 		goto eatbrac;
    492 	    }
    493 	    if (bitset)
    494 		stderror(ERR_DOLQUEST);
    495 	    vp = adrof(STRargv);
    496 	    if (vp == 0) {
    497 		vp = &nulargv;
    498 		goto eatmod;
    499 	    }
    500 	    break;
    501 	}
    502 	if (!alnum(c))
    503 	    stderror(ERR_VARALNUM);
    504 	for (;;) {
    505 	    *np++ = c;
    506 	    c = DgetC(0);
    507 	    if (!alnum(c))
    508 		break;
    509 	    if (np >= &name[MAXVARLEN])
    510 		stderror(ERR_VARTOOLONG);
    511 	}
    512 	*np++ = 0;
    513 	unDredc(c);
    514 	vp = adrof(name);
    515     }
    516     if (bitset) {
    517 	dolp = (vp || getenv(short2str(name))) ? STR1 : STR0;
    518 	goto eatbrac;
    519     }
    520     if (vp == 0) {
    521 	np = str2short(getenv(short2str(name)));
    522 	if (np) {
    523 	    fixDolMod();
    524 	    setDolp(np);
    525 	    goto eatbrac;
    526 	}
    527 	udvar(name);
    528     }
    529     c = DgetC(0);
    530     upb = blklen(vp->vec);
    531     if (dimen == 0 && subscr == 0 && c == '[') {
    532 	np = name;
    533 	for (;;) {
    534 	    c = DgetC(DODOL);	/* Allow $ expand within [ ] */
    535 	    if (c == ']')
    536 		break;
    537 	    if (c == '\n' || c == DEOF)
    538 		stderror(ERR_INCBR);
    539 	    if (np >= &name[sizeof(name) / sizeof(Char) - 2])
    540 		stderror(ERR_VARTOOLONG);
    541 	    *np++ = c;
    542 	}
    543 	*np = 0, np = name;
    544 	if (dolp || dolcnt)	/* $ exp must end before ] */
    545 	    stderror(ERR_EXPORD);
    546 	if (!*np)
    547 	    stderror(ERR_SYNTAX);
    548 	if (Isdigit(*np)) {
    549 	    int     i;
    550 
    551 	    for (i = 0; Isdigit(*np); i = i * 10 + *np++ - '0')
    552 		continue;
    553 	    if ((i < 0 || i > upb) && !any("-*", *np)) {
    554 		dolerror(vp->v_name);
    555 		return;
    556 	    }
    557 	    lwb = i;
    558 	    if (!*np)
    559 		upb = lwb, np = STRstar;
    560 	}
    561 	if (*np == '*')
    562 	    np++;
    563 	else if (*np != '-')
    564 	    stderror(ERR_MISSING, '-');
    565 	else {
    566 	    int i = upb;
    567 
    568 	    np++;
    569 	    if (Isdigit(*np)) {
    570 		i = 0;
    571 		while (Isdigit(*np))
    572 		    i = i * 10 + *np++ - '0';
    573 		if (i < 0 || i > upb) {
    574 		    dolerror(vp->v_name);
    575 		    return;
    576 		}
    577 	    }
    578 	    if (i < lwb)
    579 		upb = lwb - 1;
    580 	    else
    581 		upb = i;
    582 	}
    583 	if (lwb == 0) {
    584 	    if (upb != 0) {
    585 		dolerror(vp->v_name);
    586 		return;
    587 	    }
    588 	    upb = -1;
    589 	}
    590 	if (*np)
    591 	    stderror(ERR_SYNTAX);
    592     }
    593     else {
    594 	if (subscr > 0) {
    595 	    if (subscr > upb)
    596 		lwb = 1, upb = 0;
    597 	    else
    598 		lwb = upb = subscr;
    599 	}
    600 	unDredc(c);
    601     }
    602     if (dimen) {
    603 	Char   *cp = putn(upb - lwb + 1);
    604 
    605 	addla(cp);
    606 	xfree((ptr_t) cp);
    607     }
    608     else {
    609 eatmod:
    610 	fixDolMod();
    611 	dolnxt = &vp->vec[lwb - 1];
    612 	dolcnt = upb - lwb + 1;
    613     }
    614 eatbrac:
    615     if (sc == '{') {
    616 	c = Dredc();
    617 	if (c != '}')
    618 	    stderror(ERR_MISSING, '}');
    619     }
    620 }
    621 
    622 static void
    623 fixDolMod(void)
    624 {
    625     int c;
    626 
    627     c = DgetC(0);
    628     if (c == ':') {
    629 	do {
    630 	    c = DgetC(0), dolmcnt = 1, dolwcnt = 1;
    631 	    if (c == 'g' || c == 'a') {
    632 		if (c == 'g')
    633 		    dolmcnt = 10000;
    634 		else
    635 		    dolwcnt = 10000;
    636 		c = DgetC(0);
    637 	    }
    638 	    if ((c == 'g' && dolmcnt != 10000) ||
    639 		(c == 'a' && dolwcnt != 10000)) {
    640 		if (c == 'g')
    641 		    dolmcnt = 10000;
    642 		else
    643 		    dolwcnt = 10000;
    644 		c = DgetC(0);
    645 	    }
    646 
    647 	    if (c == 's') {	/* [eichin:19910926.0755EST] */
    648 		int delimcnt = 2;
    649 		int delim = DgetC(0);
    650 		dolmod[dolnmod++] = c;
    651 		dolmod[dolnmod++] = delim;
    652 
    653 		if (!delim || letter(delim)
    654 		    || Isdigit(delim) || any(" \t\n", delim)) {
    655 		    seterror(ERR_BADSUBST);
    656 		    break;
    657 		}
    658 		while ((c = DgetC(0)) != (-1)) {
    659 		    dolmod[dolnmod++] = c;
    660 		    if(c == delim) delimcnt--;
    661 		    if(!delimcnt) break;
    662 		}
    663 		if(delimcnt) {
    664 		    seterror(ERR_BADSUBST);
    665 		    break;
    666 		}
    667 		continue;
    668 	    }
    669 	    if (!any("htrqxes", c))
    670 		stderror(ERR_BADMOD, c);
    671 	    dolmod[dolnmod++] = c;
    672 	    if (c == 'q')
    673 		dolmcnt = 10000;
    674 	}
    675 	while ((c = DgetC(0)) == ':');
    676 	unDredc(c);
    677     }
    678     else
    679 	unDredc(c);
    680 }
    681 
    682 static void
    683 setDolp(Char *cp)
    684 {
    685     Char *dp;
    686     int i;
    687 
    688     if (dolnmod == 0 || dolmcnt == 0) {
    689 	dolp = cp;
    690 	return;
    691     }
    692     dp = cp = Strsave(cp);
    693     for (i = 0; i < dolnmod; i++) {
    694 	/* handle s// [eichin:19910926.0510EST] */
    695 	if(dolmod[i] == 's') {
    696 	    int delim;
    697 	    Char *lhsub, *rhsub, *np;
    698 	    size_t lhlen = 0, rhlen = 0;
    699 	    int didmod = 0;
    700 
    701 	    delim = dolmod[++i];
    702 	    if (!delim || letter(delim)
    703 		|| Isdigit(delim) || any(" \t\n", delim)) {
    704 		seterror(ERR_BADSUBST);
    705 		break;
    706 	    }
    707 	    lhsub = &dolmod[++i];
    708 	    while(dolmod[i] != delim && dolmod[++i]) {
    709 		lhlen++;
    710 	    }
    711 	    dolmod[i] = 0;
    712 	    rhsub = &dolmod[++i];
    713 	    while(dolmod[i] != delim && dolmod[++i]) {
    714 		rhlen++;
    715 	    }
    716 	    dolmod[i] = 0;
    717 
    718 	    do {
    719 		dp = Strstr(cp, lhsub);
    720 		if (dp) {
    721 		    np = (Char *)xmalloc(
    722 		        (size_t)((Strlen(cp) + 1 - lhlen + rhlen) *
    723 		        sizeof(Char)));
    724 		    (void)Strncpy(np, cp, dp - cp);
    725 		    (void)Strcpy(np + (dp - cp), rhsub);
    726 		    (void)Strcpy(np + (dp - cp) + rhlen, dp + lhlen);
    727 
    728 		    xfree((ptr_t) cp);
    729 		    dp = cp = np;
    730 		    didmod = 1;
    731 		} else {
    732 		    /* should this do a seterror? */
    733 		    break;
    734 		}
    735 	    }
    736 	    while (dolwcnt == 10000);
    737 	    /*
    738 	     * restore dolmod for additional words
    739 	     */
    740 	    dolmod[i] = rhsub[-1] = delim;
    741 	    if (didmod)
    742 		dolmcnt--;
    743 	    else
    744 		break;
    745         } else {
    746 	    int didmod = 0;
    747 
    748 	    do {
    749 		if ((dp = domod(cp, dolmod[i]))) {
    750 		    didmod = 1;
    751 		    if (Strcmp(cp, dp) == 0) {
    752 			xfree((ptr_t) cp);
    753 			cp = dp;
    754 			break;
    755 		    }
    756 		    else {
    757 			xfree((ptr_t) cp);
    758 			cp = dp;
    759 		    }
    760 		}
    761 		else
    762 		    break;
    763 	    }
    764 	    while (dolwcnt == 10000);
    765 	    dp = cp;
    766 	    if (didmod)
    767 		dolmcnt--;
    768 	    else
    769 		break;
    770 	}
    771     }
    772 
    773     if (dp) {
    774 	addla(dp);
    775 	xfree((ptr_t) dp);
    776     }
    777     else
    778 	addla(cp);
    779 
    780     dolp = STRNULL;
    781     if (seterr)
    782 	stderror(ERR_OLD);
    783 }
    784 
    785 static void
    786 unDredc(int c)
    787 {
    788     Dpeekrd = c;
    789 }
    790 
    791 static int
    792 Dredc(void)
    793 {
    794     int c;
    795 
    796     if ((c = Dpeekrd) != '\0') {
    797 	Dpeekrd = 0;
    798 	return (c);
    799     }
    800     if (Dcp && (c = *Dcp++))
    801 	return (c & (QUOTE | TRIM));
    802     if (*Dvp == 0) {
    803 	Dcp = 0;
    804 	return (DEOF);
    805     }
    806     Dcp = *Dvp++;
    807     return (' ');
    808 }
    809 
    810 static void
    811 Dtestq(int c)
    812 {
    813     if (cmap(c, QUOTES))
    814 	gflag = 1;
    815 }
    816 
    817 /*
    818  * Form a shell temporary file (in unit 0) from the words
    819  * of the shell input up to EOF or a line the same as "term".
    820  * Unit 0 should have been closed before this call.
    821  */
    822 void
    823 /*ARGSUSED*/
    824 heredoc(Char *term)
    825 {
    826     Char obuf[BUFSIZE], lbuf[BUFSIZE], mbuf[BUFSIZE];
    827     struct timeval tv;
    828     Char *Dv[2], *lbp, *obp, *mbp, **vp;
    829     char *tmp;
    830     int c, ocnt, lcnt, mcnt;
    831     bool quoted;
    832 
    833 again:
    834     tmp = short2str(shtemp);
    835     if (open(tmp, O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600) < 0) {
    836 	if (errno == EEXIST) {
    837 	    if (unlink(tmp) == -1) {
    838 		(void)gettimeofday(&tv, NULL);
    839 		shtemp = Strspl(STRtmpsh, putn((((int)tv.tv_sec) ^
    840 		    ((int)tv.tv_usec) ^ ((int)getpid())) & 0x00ffffff));
    841 	    }
    842 	    goto again;
    843 	}
    844 	stderror(ERR_SYSTEM, tmp, strerror(errno));
    845     }
    846     (void)unlink(tmp);		/* 0 0 inode! */
    847     Dv[0] = term;
    848     Dv[1] = NULL;
    849     gflag = 0;
    850     trim(Dv);
    851     rscan(Dv, Dtestq);
    852     quoted = gflag;
    853     ocnt = BUFSIZE;
    854     obp = obuf;
    855     for (;;) {
    856 	/*
    857 	 * Read up a line
    858 	 */
    859 	lbp = lbuf;
    860 	lcnt = BUFSIZE - 4;
    861 	for (;;) {
    862 	    c = readc(1);	/* 1 -> Want EOF returns */
    863 	    if (c < 0 || c == '\n')
    864 		break;
    865 	    if ((c &= TRIM) != '\0') {
    866 		*lbp++ = c;
    867 		if (--lcnt < 0) {
    868 		    setname("<<");
    869 		    stderror(ERR_NAME | ERR_OVERFLOW);
    870 		}
    871 	    }
    872 	}
    873 	*lbp = 0;
    874 
    875 	/*
    876 	 * Check for EOF or compare to terminator -- before expansion
    877 	 */
    878 	if (c < 0 || eq(lbuf, term)) {
    879 	    (void)write(0, short2str(obuf), (size_t)(BUFSIZE - ocnt));
    880 	    (void)lseek(0, (off_t)0, SEEK_SET);
    881 	    return;
    882 	}
    883 
    884 	/*
    885 	 * If term was quoted or -n just pass it on
    886 	 */
    887 	if (quoted || noexec) {
    888 	    *lbp++ = '\n';
    889 	    *lbp = 0;
    890 	    for (lbp = lbuf; (c = *lbp++) != '\0';) {
    891 		*obp++ = c;
    892 		if (--ocnt == 0) {
    893 		    (void) write(0, short2str(obuf), BUFSIZE);
    894 		    obp = obuf;
    895 		    ocnt = BUFSIZE;
    896 		}
    897 	    }
    898 	    continue;
    899 	}
    900 
    901 	/*
    902 	 * Term wasn't quoted so variable and then command expand the input
    903 	 * line
    904 	 */
    905 	Dcp = lbuf;
    906 	Dvp = Dv + 1;
    907 	mbp = mbuf;
    908 	mcnt = BUFSIZE - 4;
    909 	for (;;) {
    910 	    c = DgetC(DODOL);
    911 	    if (c == DEOF)
    912 		break;
    913 	    if ((c &= TRIM) == 0)
    914 		continue;
    915 	    /* \ quotes \ $ ` here */
    916 	    if (c == '\\') {
    917 		c = DgetC(0);
    918 		if (!any("$\\`", c))
    919 		    unDgetC(c | QUOTE), c = '\\';
    920 		else
    921 		    c |= QUOTE;
    922 	    }
    923 	    *mbp++ = c;
    924 	    if (--mcnt == 0) {
    925 		setname("<<");
    926 		stderror(ERR_NAME | ERR_OVERFLOW);
    927 	    }
    928 	}
    929 	*mbp++ = 0;
    930 
    931 	/*
    932 	 * If any ` in line do command substitution
    933 	 */
    934 	mbp = mbuf;
    935 	if (any(short2str(mbp), '`')) {
    936 	    /*
    937 	     * 1 arg to dobackp causes substitution to be literal. Words are
    938 	     * broken only at newlines so that all blanks and tabs are
    939 	     * preserved.  Blank lines (null words) are not discarded.
    940 	     */
    941 	    vp = dobackp(mbuf, 1);
    942 	}
    943 	else
    944 	    /* Setup trivial vector similar to return of dobackp */
    945 	    Dv[0] = mbp, Dv[1] = NULL, vp = Dv;
    946 
    947 	/*
    948 	 * Resurrect the words from the command substitution each separated by
    949 	 * a newline.  Note that the last newline of a command substitution
    950 	 * will have been discarded, but we put a newline after the last word
    951 	 * because this represents the newline after the last input line!
    952 	 */
    953 	for (; *vp; vp++) {
    954 	    for (mbp = *vp; *mbp; mbp++) {
    955 		*obp++ = *mbp & TRIM;
    956 		if (--ocnt == 0) {
    957 		    (void)write(0, short2str(obuf), BUFSIZE);
    958 		    obp = obuf;
    959 		    ocnt = BUFSIZE;
    960 		}
    961 	    }
    962 	    *obp++ = '\n';
    963 	    if (--ocnt == 0) {
    964 		(void)write(0, short2str(obuf), BUFSIZE);
    965 		obp = obuf;
    966 		ocnt = BUFSIZE;
    967 	    }
    968 	}
    969 	if (pargv)
    970 	    blkfree(pargv), pargv = 0;
    971     }
    972 }
    973