xref: /netbsd-src/bin/csh/dol.c (revision 9fbd88883c38d0c0fbfcbe66d76fe6b0fab3f9de)
1 /* $NetBSD: dol.c,v 1.19 2002/01/30 20:53:33 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 1.19 2002/01/30 20:53:33 christos 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 	    if (subscr == 0) {
481 		if (bitset) {
482 		    dolp = ffile ? STR1 : STR0;
483 		    goto eatbrac;
484 		}
485 		if (ffile == 0)
486 		    stderror(ERR_DOLZERO);
487 		fixDolMod();
488 		setDolp(ffile);
489 		goto eatbrac;
490 	    }
491 	    if (bitset)
492 		stderror(ERR_DOLQUEST);
493 	    vp = adrof(STRargv);
494 	    if (vp == 0) {
495 		vp = &nulargv;
496 		goto eatmod;
497 	    }
498 	    break;
499 	}
500 	if (!alnum(c))
501 	    stderror(ERR_VARALNUM);
502 	for (;;) {
503 	    *np++ = c;
504 	    c = DgetC(0);
505 	    if (!alnum(c))
506 		break;
507 	    if (np >= &name[MAXVARLEN])
508 		stderror(ERR_VARTOOLONG);
509 	}
510 	*np++ = 0;
511 	unDredc(c);
512 	vp = adrof(name);
513     }
514     if (bitset) {
515 	dolp = (vp || getenv(short2str(name))) ? STR1 : STR0;
516 	goto eatbrac;
517     }
518     if (vp == 0) {
519 	np = str2short(getenv(short2str(name)));
520 	if (np) {
521 	    fixDolMod();
522 	    setDolp(np);
523 	    goto eatbrac;
524 	}
525 	udvar(name);
526     }
527     c = DgetC(0);
528     upb = blklen(vp->vec);
529     if (dimen == 0 && subscr == 0 && c == '[') {
530 	np = name;
531 	for (;;) {
532 	    c = DgetC(DODOL);	/* Allow $ expand within [ ] */
533 	    if (c == ']')
534 		break;
535 	    if (c == '\n' || c == DEOF)
536 		stderror(ERR_INCBR);
537 	    if (np >= &name[sizeof(name) / sizeof(Char) - 2])
538 		stderror(ERR_VARTOOLONG);
539 	    *np++ = c;
540 	}
541 	*np = 0, np = name;
542 	if (dolp || dolcnt)	/* $ exp must end before ] */
543 	    stderror(ERR_EXPORD);
544 	if (!*np)
545 	    stderror(ERR_SYNTAX);
546 	if (Isdigit(*np)) {
547 	    int     i;
548 
549 	    for (i = 0; Isdigit(*np); i = i * 10 + *np++ - '0')
550 		continue;
551 	    if ((i < 0 || i > upb) && !any("-*", *np)) {
552 		dolerror(vp->v_name);
553 		return;
554 	    }
555 	    lwb = i;
556 	    if (!*np)
557 		upb = lwb, np = STRstar;
558 	}
559 	if (*np == '*')
560 	    np++;
561 	else if (*np != '-')
562 	    stderror(ERR_MISSING, '-');
563 	else {
564 	    int i = upb;
565 
566 	    np++;
567 	    if (Isdigit(*np)) {
568 		i = 0;
569 		while (Isdigit(*np))
570 		    i = i * 10 + *np++ - '0';
571 		if (i < 0 || i > upb) {
572 		    dolerror(vp->v_name);
573 		    return;
574 		}
575 	    }
576 	    if (i < lwb)
577 		upb = lwb - 1;
578 	    else
579 		upb = i;
580 	}
581 	if (lwb == 0) {
582 	    if (upb != 0) {
583 		dolerror(vp->v_name);
584 		return;
585 	    }
586 	    upb = -1;
587 	}
588 	if (*np)
589 	    stderror(ERR_SYNTAX);
590     }
591     else {
592 	if (subscr > 0) {
593 	    if (subscr > upb)
594 		lwb = 1, upb = 0;
595 	    else
596 		lwb = upb = subscr;
597 	}
598 	unDredc(c);
599     }
600     if (dimen) {
601 	Char   *cp = putn(upb - lwb + 1);
602 
603 	addla(cp);
604 	xfree((ptr_t) cp);
605     }
606     else {
607 eatmod:
608 	fixDolMod();
609 	dolnxt = &vp->vec[lwb - 1];
610 	dolcnt = upb - lwb + 1;
611     }
612 eatbrac:
613     if (sc == '{') {
614 	c = Dredc();
615 	if (c != '}')
616 	    stderror(ERR_MISSING, '}');
617     }
618 }
619 
620 static void
621 fixDolMod(void)
622 {
623     int c;
624 
625     c = DgetC(0);
626     if (c == ':') {
627 	do {
628 	    c = DgetC(0), dolmcnt = 1, dolwcnt = 1;
629 	    if (c == 'g' || c == 'a') {
630 		if (c == 'g')
631 		    dolmcnt = 10000;
632 		else
633 		    dolwcnt = 10000;
634 		c = DgetC(0);
635 	    }
636 	    if ((c == 'g' && dolmcnt != 10000) ||
637 		(c == 'a' && dolwcnt != 10000)) {
638 		if (c == 'g')
639 		    dolmcnt = 10000;
640 		else
641 		    dolwcnt = 10000;
642 		c = DgetC(0);
643 	    }
644 
645 	    if (c == 's') {	/* [eichin:19910926.0755EST] */
646 		int delimcnt = 2;
647 		int delim = DgetC(0);
648 		dolmod[dolnmod++] = c;
649 		dolmod[dolnmod++] = delim;
650 
651 		if (!delim || letter(delim)
652 		    || Isdigit(delim) || any(" \t\n", delim)) {
653 		    seterror(ERR_BADSUBST);
654 		    break;
655 		}
656 		while ((c = DgetC(0)) != (-1)) {
657 		    dolmod[dolnmod++] = c;
658 		    if(c == delim) delimcnt--;
659 		    if(!delimcnt) break;
660 		}
661 		if(delimcnt) {
662 		    seterror(ERR_BADSUBST);
663 		    break;
664 		}
665 		continue;
666 	    }
667 	    if (!any("htrqxes", c))
668 		stderror(ERR_BADMOD, c);
669 	    dolmod[dolnmod++] = c;
670 	    if (c == 'q')
671 		dolmcnt = 10000;
672 	}
673 	while ((c = DgetC(0)) == ':');
674 	unDredc(c);
675     }
676     else
677 	unDredc(c);
678 }
679 
680 static void
681 setDolp(Char *cp)
682 {
683     Char *dp;
684     int i;
685 
686     if (dolnmod == 0 || dolmcnt == 0) {
687 	dolp = cp;
688 	return;
689     }
690     dp = cp = Strsave(cp);
691     for (i = 0; i < dolnmod; i++) {
692 	/* handle s// [eichin:19910926.0510EST] */
693 	if(dolmod[i] == 's') {
694 	    int delim;
695 	    Char *lhsub, *rhsub, *np;
696 	    size_t lhlen = 0, rhlen = 0;
697 	    int didmod = 0;
698 
699 	    delim = dolmod[++i];
700 	    if (!delim || letter(delim)
701 		|| Isdigit(delim) || any(" \t\n", delim)) {
702 		seterror(ERR_BADSUBST);
703 		break;
704 	    }
705 	    lhsub = &dolmod[++i];
706 	    while(dolmod[i] != delim && dolmod[++i]) {
707 		lhlen++;
708 	    }
709 	    dolmod[i] = 0;
710 	    rhsub = &dolmod[++i];
711 	    while(dolmod[i] != delim && dolmod[++i]) {
712 		rhlen++;
713 	    }
714 	    dolmod[i] = 0;
715 
716 	    do {
717 		dp = Strstr(cp, lhsub);
718 		if (dp) {
719 		    np = (Char *)xmalloc(
720 		        (size_t)((Strlen(cp) + 1 - lhlen + rhlen) *
721 		        sizeof(Char)));
722 		    (void)Strncpy(np, cp, dp - cp);
723 		    (void)Strcpy(np + (dp - cp), rhsub);
724 		    (void)Strcpy(np + (dp - cp) + rhlen, dp + lhlen);
725 
726 		    xfree((ptr_t) cp);
727 		    dp = cp = np;
728 		    didmod = 1;
729 		} else {
730 		    /* should this do a seterror? */
731 		    break;
732 		}
733 	    }
734 	    while (dolwcnt == 10000);
735 	    /*
736 	     * restore dolmod for additional words
737 	     */
738 	    dolmod[i] = rhsub[-1] = delim;
739 	    if (didmod)
740 		dolmcnt--;
741 	    else
742 		break;
743         } else {
744 	    int didmod = 0;
745 
746 	    do {
747 		if ((dp = domod(cp, dolmod[i]))) {
748 		    didmod = 1;
749 		    if (Strcmp(cp, dp) == 0) {
750 			xfree((ptr_t) cp);
751 			cp = dp;
752 			break;
753 		    }
754 		    else {
755 			xfree((ptr_t) cp);
756 			cp = dp;
757 		    }
758 		}
759 		else
760 		    break;
761 	    }
762 	    while (dolwcnt == 10000);
763 	    dp = cp;
764 	    if (didmod)
765 		dolmcnt--;
766 	    else
767 		break;
768 	}
769     }
770 
771     if (dp) {
772 	addla(dp);
773 	xfree((ptr_t) dp);
774     }
775     else
776 	addla(cp);
777 
778     dolp = STRNULL;
779     if (seterr)
780 	stderror(ERR_OLD);
781 }
782 
783 static void
784 unDredc(int c)
785 {
786     Dpeekrd = c;
787 }
788 
789 static int
790 Dredc(void)
791 {
792     int c;
793 
794     if ((c = Dpeekrd) != '\0') {
795 	Dpeekrd = 0;
796 	return (c);
797     }
798     if (Dcp && (c = *Dcp++))
799 	return (c & (QUOTE | TRIM));
800     if (*Dvp == 0) {
801 	Dcp = 0;
802 	return (DEOF);
803     }
804     Dcp = *Dvp++;
805     return (' ');
806 }
807 
808 static void
809 Dtestq(int c)
810 {
811     if (cmap(c, QUOTES))
812 	gflag = 1;
813 }
814 
815 /*
816  * Form a shell temporary file (in unit 0) from the words
817  * of the shell input up to EOF or a line the same as "term".
818  * Unit 0 should have been closed before this call.
819  */
820 void
821 /*ARGSUSED*/
822 heredoc(Char *term)
823 {
824     Char obuf[BUFSIZE], lbuf[BUFSIZE], mbuf[BUFSIZE];
825     struct timeval tv;
826     Char *Dv[2], *lbp, *obp, *mbp, **vp;
827     char *tmp;
828     int c, ocnt, lcnt, mcnt;
829     bool quoted;
830 
831 again:
832     tmp = short2str(shtemp);
833     if (open(tmp, O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600) < 0) {
834 	if (errno == EEXIST) {
835 	    if (unlink(tmp) == -1) {
836 		(void)gettimeofday(&tv, NULL);
837 		shtemp = Strspl(STRtmpsh, putn((((int)tv.tv_sec) ^
838 		    ((int)tv.tv_usec) ^ ((int)getpid())) & 0x00ffffff));
839 	    }
840 	    goto again;
841 	}
842 	stderror(ERR_SYSTEM, tmp, strerror(errno));
843     }
844     (void)unlink(tmp);		/* 0 0 inode! */
845     Dv[0] = term;
846     Dv[1] = NULL;
847     gflag = 0;
848     trim(Dv);
849     rscan(Dv, Dtestq);
850     quoted = gflag;
851     ocnt = BUFSIZE;
852     obp = obuf;
853     for (;;) {
854 	/*
855 	 * Read up a line
856 	 */
857 	lbp = lbuf;
858 	lcnt = BUFSIZE - 4;
859 	for (;;) {
860 	    c = readc(1);	/* 1 -> Want EOF returns */
861 	    if (c < 0 || c == '\n')
862 		break;
863 	    if ((c &= TRIM) != '\0') {
864 		*lbp++ = c;
865 		if (--lcnt < 0) {
866 		    setname("<<");
867 		    stderror(ERR_NAME | ERR_OVERFLOW);
868 		}
869 	    }
870 	}
871 	*lbp = 0;
872 
873 	/*
874 	 * Check for EOF or compare to terminator -- before expansion
875 	 */
876 	if (c < 0 || eq(lbuf, term)) {
877 	    (void)write(0, short2str(obuf), (size_t)(BUFSIZE - ocnt));
878 	    (void)lseek(0, (off_t)0, SEEK_SET);
879 	    return;
880 	}
881 
882 	/*
883 	 * If term was quoted or -n just pass it on
884 	 */
885 	if (quoted || noexec) {
886 	    *lbp++ = '\n';
887 	    *lbp = 0;
888 	    for (lbp = lbuf; (c = *lbp++) != '\0';) {
889 		*obp++ = c;
890 		if (--ocnt == 0) {
891 		    (void) write(0, short2str(obuf), BUFSIZE);
892 		    obp = obuf;
893 		    ocnt = BUFSIZE;
894 		}
895 	    }
896 	    continue;
897 	}
898 
899 	/*
900 	 * Term wasn't quoted so variable and then command expand the input
901 	 * line
902 	 */
903 	Dcp = lbuf;
904 	Dvp = Dv + 1;
905 	mbp = mbuf;
906 	mcnt = BUFSIZE - 4;
907 	for (;;) {
908 	    c = DgetC(DODOL);
909 	    if (c == DEOF)
910 		break;
911 	    if ((c &= TRIM) == 0)
912 		continue;
913 	    /* \ quotes \ $ ` here */
914 	    if (c == '\\') {
915 		c = DgetC(0);
916 		if (!any("$\\`", c))
917 		    unDgetC(c | QUOTE), c = '\\';
918 		else
919 		    c |= QUOTE;
920 	    }
921 	    *mbp++ = c;
922 	    if (--mcnt == 0) {
923 		setname("<<");
924 		stderror(ERR_NAME | ERR_OVERFLOW);
925 	    }
926 	}
927 	*mbp++ = 0;
928 
929 	/*
930 	 * If any ` in line do command substitution
931 	 */
932 	mbp = mbuf;
933 	if (any(short2str(mbp), '`')) {
934 	    /*
935 	     * 1 arg to dobackp causes substitution to be literal. Words are
936 	     * broken only at newlines so that all blanks and tabs are
937 	     * preserved.  Blank lines (null words) are not discarded.
938 	     */
939 	    vp = dobackp(mbuf, 1);
940 	}
941 	else
942 	    /* Setup trivial vector similar to return of dobackp */
943 	    Dv[0] = mbp, Dv[1] = NULL, vp = Dv;
944 
945 	/*
946 	 * Resurrect the words from the command substitution each separated by
947 	 * a newline.  Note that the last newline of a command substitution
948 	 * will have been discarded, but we put a newline after the last word
949 	 * because this represents the newline after the last input line!
950 	 */
951 	for (; *vp; vp++) {
952 	    for (mbp = *vp; *mbp; mbp++) {
953 		*obp++ = *mbp & TRIM;
954 		if (--ocnt == 0) {
955 		    (void)write(0, short2str(obuf), BUFSIZE);
956 		    obp = obuf;
957 		    ocnt = BUFSIZE;
958 		}
959 	    }
960 	    *obp++ = '\n';
961 	    if (--ocnt == 0) {
962 		(void)write(0, short2str(obuf), BUFSIZE);
963 		obp = obuf;
964 		ocnt = BUFSIZE;
965 	    }
966 	}
967 	if (pargv)
968 	    blkfree(pargv), pargv = 0;
969     }
970 }
971