xref: /netbsd-src/bin/csh/dol.c (revision fdecd6a253f999ae92b139670d9e15cc9df4497c)
1 /*	$NetBSD: dol.c,v 1.10 1997/07/04 21:23:56 christos 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 1.10 1997/07/04 21:23:56 christos Exp $");
42 #endif
43 #endif /* not lint */
44 
45 #include <sys/types.h>
46 #include <fcntl.h>
47 #include <errno.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #if __STDC__
52 # include <stdarg.h>
53 #else
54 # include <varargs.h>
55 #endif
56 
57 #include "csh.h"
58 #include "extern.h"
59 
60 /*
61  * These routines perform variable substitution and quoting via ' and ".
62  * To this point these constructs have been preserved in the divided
63  * input words.  Here we expand variables and turn quoting via ' and " into
64  * QUOTE bits on characters (which prevent further interpretation).
65  * If the `:q' modifier was applied during history expansion, then
66  * some QUOTEing may have occurred already, so we dont "trim()" here.
67  */
68 
69 static int Dpeekc, Dpeekrd;	/* Peeks for DgetC and Dreadc */
70 static Char *Dcp, **Dvp;	/* Input vector for Dreadc */
71 
72 #define	DEOF	-1
73 
74 #define	unDgetC(c)	Dpeekc = c
75 
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 (BUFSIZ - 4)
85 #define MAXMOD MAXWLEN		/* This cannot overflow	*/
86 static Char *dolp;		/* Remaining chars from this word */
87 static Char **dolnxt;		/* Further words */
88 static int dolcnt;		/* Count of further words */
89 static Char dolmod[MAXMOD];	/* : modifier character */
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 __P((Char **));
95 static Char	*Dpack __P((Char *, Char *));
96 static int	 Dword __P((void));
97 static void	 dolerror __P((Char *));
98 static int	 DgetC __P((int));
99 static void	 Dgetdol __P((void));
100 static void	 fixDolMod __P((void));
101 static void	 setDolp __P((Char *));
102 static void	 unDredc __P((int));
103 static int	 Dredc __P((void));
104 static void	 Dtestq __P((int));
105 
106 
107 /*
108  * Fix up the $ expansions and quotations in the
109  * argument list to command t.
110  */
111 void
112 Dfix(t)
113     struct command *t;
114 {
115     Char **pp;
116     Char *p;
117 
118     if (noexec)
119 	return;
120     /* Note that t_dcom isn't trimmed thus !...:q's aren't lost */
121     for (pp = t->t_dcom; (p = *pp++) != NULL;)
122 	for (; *p; p++) {
123 	    if (cmap(*p, _DOL | QUOTES)) {	/* $, \, ', ", ` */
124 		Dfix2(t->t_dcom);	/* found one */
125 		blkfree(t->t_dcom);
126 		t->t_dcom = gargv;
127 		gargv = 0;
128 		return;
129 	    }
130 	}
131 }
132 
133 /*
134  * $ substitute one word, for i/o redirection
135  */
136 Char   *
137 Dfix1(cp)
138     Char *cp;
139 {
140     Char   *Dv[2];
141 
142     if (noexec)
143 	return (0);
144     Dv[0] = cp;
145     Dv[1] = NULL;
146     Dfix2(Dv);
147     if (gargc != 1) {
148 	setname(vis_str(cp));
149 	stderror(ERR_NAME | ERR_AMBIG);
150     }
151     cp = Strsave(gargv[0]);
152     blkfree(gargv), gargv = 0;
153     return (cp);
154 }
155 
156 /*
157  * Subroutine to do actual fixing after state initialization.
158  */
159 static void
160 Dfix2(v)
161     Char  **v;
162 {
163     ginit();			/* Initialize glob's area pointers */
164     Dvp = v;
165     Dcp = STRNULL;		/* Setup input vector for Dreadc */
166     unDgetC(0);
167     unDredc(0);			/* Clear out any old peeks (at error) */
168     dolp = 0;
169     dolcnt = 0;			/* Clear out residual $ expands (...) */
170     while (Dword())
171 	continue;
172 }
173 
174 /*
175  * Pack up more characters in this word
176  */
177 static Char *
178 Dpack(wbuf, wp)
179     Char   *wbuf, *wp;
180 {
181     int c;
182     int i = MAXWLEN - (wp - wbuf);
183 
184     for (;;) {
185 	c = DgetC(DODOL);
186 	if (c == '\\') {
187 	    c = DgetC(0);
188 	    if (c == DEOF) {
189 		unDredc(c);
190 		*wp = 0;
191 		Gcat(STRNULL, wbuf);
192 		return (NULL);
193 	    }
194 	    if (c == '\n')
195 		c = ' ';
196 	    else
197 		c |= QUOTE;
198 	}
199 	if (c == DEOF) {
200 	    unDredc(c);
201 	    *wp = 0;
202 	    Gcat(STRNULL, wbuf);
203 	    return (NULL);
204 	}
205 	if (cmap(c, _SP | _NL | _QF | _QB)) {	/* sp \t\n'"` */
206 	    unDgetC(c);
207 	    if (cmap(c, QUOTES))
208 		return (wp);
209 	    *wp++ = 0;
210 	    Gcat(STRNULL, wbuf);
211 	    return (NULL);
212 	}
213 	if (--i <= 0)
214 	    stderror(ERR_WTOOLONG);
215 	*wp++ = c;
216     }
217 }
218 
219 /*
220  * Get a word.  This routine is analogous to the routine
221  * word() in sh.lex.c for the main lexical input.  One difference
222  * here is that we don't get a newline to terminate our expansion.
223  * Rather, DgetC will return a DEOF when we hit the end-of-input.
224  */
225 static int
226 Dword()
227 {
228     int c, c1;
229     Char    wbuf[BUFSIZ];
230     Char *wp = wbuf;
231     int i = MAXWLEN;
232     bool dolflg;
233     bool    sofar = 0, done = 0;
234 
235     while (!done) {
236 	done = 1;
237 	c = DgetC(DODOL);
238 	switch (c) {
239 
240 	case DEOF:
241 	    if (sofar == 0)
242 		return (0);
243 	    /* finish this word and catch the code above the next time */
244 	    unDredc(c);
245 	    /* fall into ... */
246 
247 	case '\n':
248 	    *wp = 0;
249 	    Gcat(STRNULL, wbuf);
250 	    return (1);
251 
252 	case ' ':
253 	case '\t':
254 	    done = 0;
255 	    break;
256 
257 	case '`':
258 	    /* We preserve ` quotations which are done yet later */
259 	    *wp++ = c, --i;
260 	case '\'':
261 	case '"':
262 	    /*
263 	     * Note that DgetC never returns a QUOTES character from an
264 	     * expansion, so only true input quotes will get us here or out.
265 	     */
266 	    c1 = c;
267 	    dolflg = c1 == '"' ? DODOL : 0;
268 	    for (;;) {
269 		c = DgetC(dolflg);
270 		if (c == c1)
271 		    break;
272 		if (c == '\n' || c == DEOF)
273 		    stderror(ERR_UNMATCHED, c1);
274 		if ((c & (QUOTE | TRIM)) == ('\n' | QUOTE))
275 		    --wp, ++i;
276 		if (--i <= 0)
277 		    stderror(ERR_WTOOLONG);
278 		switch (c1) {
279 
280 		case '"':
281 		    /*
282 		     * Leave any `s alone for later. Other chars are all
283 		     * quoted, thus `...` can tell it was within "...".
284 		     */
285 		    *wp++ = c == '`' ? '`' : c | QUOTE;
286 		    break;
287 
288 		case '\'':
289 		    /* Prevent all further interpretation */
290 		    *wp++ = c | QUOTE;
291 		    break;
292 
293 		case '`':
294 		    /* Leave all text alone for later */
295 		    *wp++ = c;
296 		    break;
297 
298 		default:
299 		    break;
300 		}
301 	    }
302 	    if (c1 == '`')
303 		*wp++ = '`' /* i--; eliminated */;
304 	    sofar = 1;
305 	    if ((wp = Dpack(wbuf, wp)) == NULL)
306 		return (1);
307 	    else {
308 		i = MAXWLEN - (wp - wbuf);
309 		done = 0;
310 	    }
311 	    break;
312 
313 	case '\\':
314 	    c = DgetC(0);	/* No $ subst! */
315 	    if (c == '\n' || c == DEOF) {
316 		done = 0;
317 		break;
318 	    }
319 	    c |= QUOTE;
320 	    break;
321 
322 	default:
323 	    break;
324 	}
325 	if (done) {
326 	    unDgetC(c);
327 	    sofar = 1;
328 	    if ((wp = Dpack(wbuf, wp)) == NULL)
329 		return (1);
330 	    else {
331 		i = MAXWLEN - (wp - wbuf);
332 		done = 0;
333 	    }
334 	}
335     }
336     /* Really NOTREACHED */
337     return (0);
338 }
339 
340 
341 /*
342  * Get a character, performing $ substitution unless flag is 0.
343  * Any QUOTES character which is returned from a $ expansion is
344  * QUOTEd so that it will not be recognized above.
345  */
346 static int
347 DgetC(flag)
348     int flag;
349 {
350     int c;
351 
352 top:
353     if ((c = Dpeekc) != '\0') {
354 	Dpeekc = 0;
355 	return (c);
356     }
357     if (lap) {
358 	c = *lap++ & (QUOTE | TRIM);
359 	if (c == 0) {
360 	    lap = 0;
361 	    goto top;
362 	}
363 quotspec:
364 	if (cmap(c, QUOTES))
365 	    return (c | QUOTE);
366 	return (c);
367     }
368     if (dolp) {
369 	if ((c = *dolp++ & (QUOTE | TRIM)) != '\0')
370 	    goto quotspec;
371 	if (dolcnt > 0) {
372 	    setDolp(*dolnxt++);
373 	    --dolcnt;
374 	    return (' ');
375 	}
376 	dolp = 0;
377     }
378     if (dolcnt > 0) {
379 	setDolp(*dolnxt++);
380 	--dolcnt;
381 	goto top;
382     }
383     c = Dredc();
384     if (c == '$' && flag) {
385 	Dgetdol();
386 	goto top;
387     }
388     return (c);
389 }
390 
391 static Char *nulvec[] = {0};
392 static struct varent nulargv = {nulvec, STRargv, { NULL, NULL, NULL }, 0};
393 
394 static void
395 dolerror(s)
396     Char   *s;
397 {
398     setname(vis_str(s));
399     stderror(ERR_NAME | ERR_RANGE);
400 }
401 
402 /*
403  * Handle the multitudinous $ expansion forms.
404  * Ugh.
405  */
406 static void
407 Dgetdol()
408 {
409     Char *np;
410     struct varent *vp = NULL;
411     Char    name[4 * MAXVARLEN + 1];
412     int     c, sc;
413     int     subscr = 0, lwb = 1, upb = 0;
414     bool    dimen = 0, bitset = 0;
415     char    tnp;
416     Char    wbuf[BUFSIZ];
417     static Char *dolbang = NULL;
418 
419     dolnmod = dolmcnt = dolwcnt = 0;
420     c = sc = DgetC(0);
421     if (c == '{')
422 	c = DgetC(0);		/* sc is { to take } later */
423     if ((c & TRIM) == '#')
424 	dimen++, c = DgetC(0);	/* $# takes dimension */
425     else if (c == '?')
426 	bitset++, c = DgetC(0);	/* $? tests existence */
427     switch (c) {
428 
429     case '!':
430 	if (dimen || bitset)
431 	    stderror(ERR_SYNTAX);
432 	if (backpid != 0) {
433 	    if (dolbang)
434 		xfree((ptr_t) dolbang);
435 	    setDolp(dolbang = putn(backpid));
436 	}
437 	goto eatbrac;
438 
439     case '$':
440 	if (dimen || bitset)
441 	    stderror(ERR_SYNTAX);
442 	setDolp(doldol);
443 	goto eatbrac;
444 
445     case '<' | QUOTE:
446 	if (bitset)
447 	    stderror(ERR_NOTALLOWED, "$?<");
448 	if (dimen)
449 	    stderror(ERR_NOTALLOWED, "$?#");
450 	for (np = wbuf; read(OLDSTD, &tnp, 1) == 1; np++) {
451 	    *np = (unsigned char) tnp;
452 	    if (np >= &wbuf[BUFSIZ - 1])
453 		stderror(ERR_LTOOLONG);
454 	    if (tnp == '\n')
455 		break;
456 	}
457 	*np = 0;
458 	/*
459 	 * KLUDGE: dolmod is set here because it will cause setDolp to call
460 	 * domod and thus to copy wbuf. Otherwise setDolp would use it
461 	 * directly. If we saved it ourselves, no one would know when to free
462 	 * it. The actual function of the 'q' causes filename expansion not to
463 	 * be done on the interpolated value.
464 	 */
465 	dolmod[dolnmod++] = 'q';
466 	dolmcnt = 10000;
467 	setDolp(wbuf);
468 	goto eatbrac;
469 
470     case DEOF:
471     case '\n':
472 	stderror(ERR_SYNTAX);
473 	/* NOTREACHED */
474 	break;
475 
476     case '*':
477 	(void) Strcpy(name, STRargv);
478 	vp = adrof(STRargv);
479 	subscr = -1;		/* Prevent eating [...] */
480 	break;
481 
482     default:
483 	np = name;
484 	if (Isdigit(c)) {
485 	    if (dimen)
486 		stderror(ERR_NOTALLOWED, "$#<num>");
487 	    subscr = 0;
488 	    do {
489 		subscr = subscr * 10 + c - '0';
490 		c = DgetC(0);
491 	    } while (Isdigit(c));
492 	    unDredc(c);
493 	    if (subscr < 0) {
494 		dolerror(vp->v_name);
495 		return;
496 	    }
497 	    if (subscr == 0) {
498 		if (bitset) {
499 		    dolp = ffile ? STR1 : STR0;
500 		    goto eatbrac;
501 		}
502 		if (ffile == 0)
503 		    stderror(ERR_DOLZERO);
504 		fixDolMod();
505 		setDolp(ffile);
506 		goto eatbrac;
507 	    }
508 	    if (bitset)
509 		stderror(ERR_DOLQUEST);
510 	    vp = adrof(STRargv);
511 	    if (vp == 0) {
512 		vp = &nulargv;
513 		goto eatmod;
514 	    }
515 	    break;
516 	}
517 	if (!alnum(c))
518 	    stderror(ERR_VARALNUM);
519 	for (;;) {
520 	    *np++ = c;
521 	    c = DgetC(0);
522 	    if (!alnum(c))
523 		break;
524 	    if (np >= &name[MAXVARLEN])
525 		stderror(ERR_VARTOOLONG);
526 	}
527 	*np++ = 0;
528 	unDredc(c);
529 	vp = adrof(name);
530     }
531     if (bitset) {
532 	dolp = (vp || getenv(short2str(name))) ? STR1 : STR0;
533 	goto eatbrac;
534     }
535     if (vp == 0) {
536 	np = str2short(getenv(short2str(name)));
537 	if (np) {
538 	    fixDolMod();
539 	    setDolp(np);
540 	    goto eatbrac;
541 	}
542 	udvar(name);
543 	/* NOTREACHED */
544     }
545     c = DgetC(0);
546     upb = blklen(vp->vec);
547     if (dimen == 0 && subscr == 0 && c == '[') {
548 	np = name;
549 	for (;;) {
550 	    c = DgetC(DODOL);	/* Allow $ expand within [ ] */
551 	    if (c == ']')
552 		break;
553 	    if (c == '\n' || c == DEOF)
554 		stderror(ERR_INCBR);
555 	    if (np >= &name[sizeof(name) / sizeof(Char) - 2])
556 		stderror(ERR_VARTOOLONG);
557 	    *np++ = c;
558 	}
559 	*np = 0, np = name;
560 	if (dolp || dolcnt)	/* $ exp must end before ] */
561 	    stderror(ERR_EXPORD);
562 	if (!*np)
563 	    stderror(ERR_SYNTAX);
564 	if (Isdigit(*np)) {
565 	    int     i;
566 
567 	    for (i = 0; Isdigit(*np); i = i * 10 + *np++ - '0')
568 		continue;
569 	    if ((i < 0 || i > upb) && !any("-*", *np)) {
570 		dolerror(vp->v_name);
571 		return;
572 	    }
573 	    lwb = i;
574 	    if (!*np)
575 		upb = lwb, np = STRstar;
576 	}
577 	if (*np == '*')
578 	    np++;
579 	else if (*np != '-')
580 	    stderror(ERR_MISSING, '-');
581 	else {
582 	    int i = upb;
583 
584 	    np++;
585 	    if (Isdigit(*np)) {
586 		i = 0;
587 		while (Isdigit(*np))
588 		    i = i * 10 + *np++ - '0';
589 		if (i < 0 || i > upb) {
590 		    dolerror(vp->v_name);
591 		    return;
592 		}
593 	    }
594 	    if (i < lwb)
595 		upb = lwb - 1;
596 	    else
597 		upb = i;
598 	}
599 	if (lwb == 0) {
600 	    if (upb != 0) {
601 		dolerror(vp->v_name);
602 		return;
603 	    }
604 	    upb = -1;
605 	}
606 	if (*np)
607 	    stderror(ERR_SYNTAX);
608     }
609     else {
610 	if (subscr > 0)
611 	    if (subscr > upb)
612 		lwb = 1, upb = 0;
613 	    else
614 		lwb = upb = subscr;
615 	unDredc(c);
616     }
617     if (dimen) {
618 	Char   *cp = putn(upb - lwb + 1);
619 
620 	addla(cp);
621 	xfree((ptr_t) cp);
622     }
623     else {
624 eatmod:
625 	fixDolMod();
626 	dolnxt = &vp->vec[lwb - 1];
627 	dolcnt = upb - lwb + 1;
628     }
629 eatbrac:
630     if (sc == '{') {
631 	c = Dredc();
632 	if (c != '}')
633 	    stderror(ERR_MISSING, '}');
634     }
635 }
636 
637 static void
638 fixDolMod()
639 {
640     int c;
641 
642     c = DgetC(0);
643     if (c == ':') {
644 	do {
645 	    c = DgetC(0), dolmcnt = 1, dolwcnt = 1;
646 	    if (c == 'g' || c == 'a') {
647 		if (c == 'g')
648 		    dolmcnt = 10000;
649 		else
650 		    dolwcnt = 10000;
651 		c = DgetC(0);
652 	    }
653 	    if ((c == 'g' && dolmcnt != 10000) ||
654 		(c == 'a' && dolwcnt != 10000)) {
655 		if (c == 'g')
656 		    dolmcnt = 10000;
657 		else
658 		    dolwcnt = 10000;
659 		c = DgetC(0);
660 	    }
661 
662 	    if (c == 's') {	/* [eichin:19910926.0755EST] */
663 		int delimcnt = 2;
664 		int delim = DgetC(0);
665 		dolmod[dolnmod++] = c;
666 		dolmod[dolnmod++] = delim;
667 
668 		if (!delim || letter(delim)
669 		    || Isdigit(delim) || any(" \t\n", delim)) {
670 		    seterror(ERR_BADSUBST);
671 		    break;
672 		}
673 		while ((c = DgetC(0)) != (-1)) {
674 		    dolmod[dolnmod++] = c;
675 		    if(c == delim) delimcnt--;
676 		    if(!delimcnt) break;
677 		}
678 		if(delimcnt) {
679 		    seterror(ERR_BADSUBST);
680 		    break;
681 		}
682 		continue;
683 	    }
684 	    if (!any("htrqxes", c))
685 		stderror(ERR_BADMOD, c);
686 	    dolmod[dolnmod++] = c;
687 	    if (c == 'q')
688 		dolmcnt = 10000;
689 	}
690 	while ((c = DgetC(0)) == ':');
691 	unDredc(c);
692     }
693     else
694 	unDredc(c);
695 }
696 
697 static void
698 setDolp(cp)
699     Char *cp;
700 {
701     Char *dp;
702     int i;
703 
704     if (dolnmod == 0 || dolmcnt == 0) {
705 	dolp = cp;
706 	return;
707     }
708     dp = cp = Strsave(cp);
709     for (i = 0; i < dolnmod; i++) {
710 	/* handle s// [eichin:19910926.0510EST] */
711 	if(dolmod[i] == 's') {
712 	    int delim;
713 	    Char *lhsub, *rhsub, *np;
714 	    size_t lhlen = 0, rhlen = 0;
715 	    int didmod = 0;
716 
717 	    delim = dolmod[++i];
718 	    if (!delim || letter(delim)
719 		|| Isdigit(delim) || any(" \t\n", delim)) {
720 		seterror(ERR_BADSUBST);
721 		break;
722 	    }
723 	    lhsub = &dolmod[++i];
724 	    while(dolmod[i] != delim && dolmod[++i]) {
725 		lhlen++;
726 	    }
727 	    dolmod[i] = 0;
728 	    rhsub = &dolmod[++i];
729 	    while(dolmod[i] != delim && dolmod[++i]) {
730 		rhlen++;
731 	    }
732 	    dolmod[i] = 0;
733 
734 	    do {
735 		dp = Strstr(cp, lhsub);
736 		if (dp) {
737 		    np = (Char *) xmalloc((size_t)
738 					  ((Strlen(cp) + 1 - lhlen + rhlen) *
739 					  sizeof(Char)));
740 		    (void) Strncpy(np, cp, dp - cp);
741 		    (void) Strcpy(np + (dp - cp), rhsub);
742 		    (void) Strcpy(np + (dp - cp) + rhlen, dp + lhlen);
743 
744 		    xfree((ptr_t) cp);
745 		    dp = cp = np;
746 		    didmod = 1;
747 		} else {
748 		    /* should this do a seterror? */
749 		    break;
750 		}
751 	    }
752 	    while (dolwcnt == 10000);
753 	    /*
754 	     * restore dolmod for additional words
755 	     */
756 	    dolmod[i] = rhsub[-1] = delim;
757 	    if (didmod)
758 		dolmcnt--;
759 	    else
760 		break;
761         } else {
762 	    int didmod = 0;
763 
764 	    do {
765 		if ((dp = domod(cp, dolmod[i]))) {
766 		    didmod = 1;
767 		    if (Strcmp(cp, dp) == 0) {
768 			xfree((ptr_t) cp);
769 			cp = dp;
770 			break;
771 		    }
772 		    else {
773 			xfree((ptr_t) cp);
774 			cp = dp;
775 		    }
776 		}
777 		else
778 		    break;
779 	    }
780 	    while (dolwcnt == 10000);
781 	    dp = cp;
782 	    if (didmod)
783 		dolmcnt--;
784 	    else
785 		break;
786 	}
787     }
788 
789     if (dp) {
790 	addla(dp);
791 	xfree((ptr_t) dp);
792     }
793     else
794 	addla(cp);
795 
796     dolp = STRNULL;
797     if (seterr)
798 	stderror(ERR_OLD);
799 }
800 
801 static void
802 unDredc(c)
803     int     c;
804 {
805 
806     Dpeekrd = c;
807 }
808 
809 static int
810 Dredc()
811 {
812     int c;
813 
814     if ((c = Dpeekrd) != '\0') {
815 	Dpeekrd = 0;
816 	return (c);
817     }
818     if (Dcp && (c = *Dcp++))
819 	return (c & (QUOTE | TRIM));
820     if (*Dvp == 0) {
821 	Dcp = 0;
822 	return (DEOF);
823     }
824     Dcp = *Dvp++;
825     return (' ');
826 }
827 
828 static void
829 Dtestq(c)
830     int c;
831 {
832 
833     if (cmap(c, QUOTES))
834 	gflag = 1;
835 }
836 
837 /*
838  * Form a shell temporary file (in unit 0) from the words
839  * of the shell input up to EOF or a line the same as "term".
840  * Unit 0 should have been closed before this call.
841  */
842 void
843 /*ARGSUSED*/
844 heredoc(term)
845     Char *term;
846 {
847     int c;
848     Char   *Dv[2];
849     Char    obuf[BUFSIZ], lbuf[BUFSIZ], mbuf[BUFSIZ];
850     int     ocnt, lcnt, mcnt;
851     Char   *lbp, *obp, *mbp;
852     Char  **vp;
853     bool    quoted;
854     char   *tmp;
855 
856     tmp = short2str(shtemp);
857     if (open(tmp, O_RDWR | O_CREAT | O_TRUNC, 0600) < 0)
858 	stderror(ERR_SYSTEM, tmp, strerror(errno));
859     (void) unlink(tmp);		/* 0 0 inode! */
860     Dv[0] = term;
861     Dv[1] = NULL;
862     gflag = 0;
863     trim(Dv);
864     rscan(Dv, Dtestq);
865     quoted = gflag;
866     ocnt = BUFSIZ;
867     obp = obuf;
868     for (;;) {
869 	/*
870 	 * Read up a line
871 	 */
872 	lbp = lbuf;
873 	lcnt = BUFSIZ - 4;
874 	for (;;) {
875 	    c = readc(1);	/* 1 -> Want EOF returns */
876 	    if (c < 0 || c == '\n')
877 		break;
878 	    if ((c &= TRIM) != '\0') {
879 		*lbp++ = c;
880 		if (--lcnt < 0) {
881 		    setname("<<");
882 		    stderror(ERR_NAME | ERR_OVERFLOW);
883 		}
884 	    }
885 	}
886 	*lbp = 0;
887 
888 	/*
889 	 * Check for EOF or compare to terminator -- before expansion
890 	 */
891 	if (c < 0 || eq(lbuf, term)) {
892 	    (void) write(0, short2str(obuf), (size_t) (BUFSIZ - ocnt));
893 	    (void) lseek(0, (off_t) 0, SEEK_SET);
894 	    return;
895 	}
896 
897 	/*
898 	 * If term was quoted or -n just pass it on
899 	 */
900 	if (quoted || noexec) {
901 	    *lbp++ = '\n';
902 	    *lbp = 0;
903 	    for (lbp = lbuf; (c = *lbp++) != '\0';) {
904 		*obp++ = c;
905 		if (--ocnt == 0) {
906 		    (void) write(0, short2str(obuf), BUFSIZ);
907 		    obp = obuf;
908 		    ocnt = BUFSIZ;
909 		}
910 	    }
911 	    continue;
912 	}
913 
914 	/*
915 	 * Term wasn't quoted so variable and then command expand the input
916 	 * line
917 	 */
918 	Dcp = lbuf;
919 	Dvp = Dv + 1;
920 	mbp = mbuf;
921 	mcnt = BUFSIZ - 4;
922 	for (;;) {
923 	    c = DgetC(DODOL);
924 	    if (c == DEOF)
925 		break;
926 	    if ((c &= TRIM) == 0)
927 		continue;
928 	    /* \ quotes \ $ ` here */
929 	    if (c == '\\') {
930 		c = DgetC(0);
931 		if (!any("$\\`", c))
932 		    unDgetC(c | QUOTE), c = '\\';
933 		else
934 		    c |= QUOTE;
935 	    }
936 	    *mbp++ = c;
937 	    if (--mcnt == 0) {
938 		setname("<<");
939 		stderror(ERR_NAME | ERR_OVERFLOW);
940 	    }
941 	}
942 	*mbp++ = 0;
943 
944 	/*
945 	 * If any ` in line do command substitution
946 	 */
947 	mbp = mbuf;
948 	if (any(short2str(mbp), '`')) {
949 	    /*
950 	     * 1 arg to dobackp causes substitution to be literal. Words are
951 	     * broken only at newlines so that all blanks and tabs are
952 	     * preserved.  Blank lines (null words) are not discarded.
953 	     */
954 	    vp = dobackp(mbuf, 1);
955 	}
956 	else
957 	    /* Setup trivial vector similar to return of dobackp */
958 	    Dv[0] = mbp, Dv[1] = NULL, vp = Dv;
959 
960 	/*
961 	 * Resurrect the words from the command substitution each separated by
962 	 * a newline.  Note that the last newline of a command substitution
963 	 * will have been discarded, but we put a newline after the last word
964 	 * because this represents the newline after the last input line!
965 	 */
966 	for (; *vp; vp++) {
967 	    for (mbp = *vp; *mbp; mbp++) {
968 		*obp++ = *mbp & TRIM;
969 		if (--ocnt == 0) {
970 		    (void) write(0, short2str(obuf), BUFSIZ);
971 		    obp = obuf;
972 		    ocnt = BUFSIZ;
973 		}
974 	    }
975 	    *obp++ = '\n';
976 	    if (--ocnt == 0) {
977 		(void) write(0, short2str(obuf), BUFSIZ);
978 		obp = obuf;
979 		ocnt = BUFSIZ;
980 	    }
981 	}
982 	if (pargv)
983 	    blkfree(pargv), pargv = 0;
984     }
985 }
986