xref: /minix/bin/csh/dol.c (revision ebfedea0)
1 /* $NetBSD: dol.c,v 1.29 2013/07/16 17:47:43 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)dol.c	8.1 (Berkeley) 5/31/93";
36 #else
37 __RCSID("$NetBSD: dol.c,v 1.29 2013/07/16 17:47:43 christos Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/types.h>
42 
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <stdarg.h>
46 #include <stddef.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include "csh.h"
52 #include "extern.h"
53 
54 /*
55  * These routines perform variable substitution and quoting via ' and ".
56  * To this point these constructs have been preserved in the divided
57  * input words.  Here we expand variables and turn quoting via ' and " into
58  * QUOTE bits on characters (which prevent further interpretation).
59  * If the `:q' modifier was applied during history expansion, then
60  * some QUOTEing may have occurred already, so we dont "trim()" here.
61  */
62 
63 static int Dpeekc, Dpeekrd;	/* Peeks for DgetC and Dreadc */
64 static Char *Dcp, **Dvp;	/* Input vector for Dreadc */
65 
66 #define	DEOF -1
67 #define	unDgetC(c) Dpeekc = c
68 #define QUOTES (_QF|_QB|_ESC)	/* \ ' " ` */
69 
70 /*
71  * The following variables give the information about the current
72  * $ expansion, recording the current word position, the remaining
73  * words within this expansion, the count of remaining words, and the
74  * information about any : modifier which is being applied.
75  */
76 #define MAXWLEN (BUFSIZE - 4)
77 #define MAXMOD MAXWLEN		/* This cannot overflow	*/
78 static Char dolmod[MAXMOD];	/* : modifier character */
79 static Char *dolp;		/* Remaining chars from this word */
80 static Char **dolnxt;		/* Further words */
81 static int dolcnt;		/* Count of further words */
82 static int dolnmod;		/* Number of modifiers */
83 static int dolmcnt;		/* :gx -> 10000, else 1 */
84 static int dolwcnt;		/* :wx -> 10000, else 1 */
85 
86 static void Dfix2(Char **);
87 static Char *Dpack(Char *, Char *);
88 static int Dword(void);
89 __dead static void dolerror(Char *);
90 static int DgetC(int);
91 static void Dgetdol(void);
92 static void fixDolMod(void);
93 static void setDolp(Char *);
94 static void unDredc(int);
95 static int Dredc(void);
96 static void Dtestq(int);
97 
98 
99 /*
100  * Fix up the $ expansions and quotations in the
101  * argument list to command t.
102  */
103 void
104 Dfix(struct command *t)
105 {
106     Char *p, **pp;
107 
108     if (noexec)
109 	return;
110     /* Note that t_dcom isn't trimmed thus !...:q's aren't lost */
111     for (pp = t->t_dcom; (p = *pp++) != NULL;)
112 	for (; *p; p++) {
113 	    if (cmap(*p, _DOL | QUOTES)) {	/* $, \, ', ", ` */
114 		Dfix2(t->t_dcom);	/* found one */
115 		blkfree(t->t_dcom);
116 		t->t_dcom = gargv;
117 		gargv = 0;
118 		return;
119 	    }
120 	}
121 }
122 
123 /*
124  * $ substitute one word, for i/o redirection
125  */
126 Char *
127 Dfix1(Char *cp)
128 {
129     Char *Dv[2];
130 
131     if (noexec)
132 	return (0);
133     Dv[0] = cp;
134     Dv[1] = NULL;
135     Dfix2(Dv);
136     if (gargc != 1) {
137 	setname(vis_str(cp));
138 	stderror(ERR_NAME | ERR_AMBIG);
139     }
140     cp = Strsave(gargv[0]);
141     blkfree(gargv), gargv = 0;
142     return (cp);
143 }
144 
145 /*
146  * Subroutine to do actual fixing after state initialization.
147  */
148 static void
149 Dfix2(Char **v)
150 {
151     ginit();			/* Initialize glob's area pointers */
152     Dvp = v;
153     Dcp = STRNULL;		/* Setup input vector for Dreadc */
154     unDgetC(0);
155     unDredc(0);			/* Clear out any old peeks (at error) */
156     dolp = 0;
157     dolcnt = 0;			/* Clear out residual $ expands (...) */
158     while (Dword())
159 	continue;
160 }
161 
162 /*
163  * Pack up more characters in this word
164  */
165 static Char *
166 Dpack(Char *wbuf, Char *wp)
167 {
168     int c;
169     ptrdiff_t i;
170 
171     i = MAXWLEN - (wp - wbuf);
172     for (;;) {
173 	c = DgetC(DODOL);
174 	if (c == '\\') {
175 	    c = DgetC(0);
176 	    if (c == DEOF) {
177 		unDredc(c);
178 		*wp = 0;
179 		Gcat(STRNULL, wbuf);
180 		return (NULL);
181 	    }
182 	    if (c == '\n')
183 		c = ' ';
184 	    else
185 		c |= QUOTE;
186 	}
187 	if (c == DEOF) {
188 	    unDredc(c);
189 	    *wp = 0;
190 	    Gcat(STRNULL, wbuf);
191 	    return (NULL);
192 	}
193 	if (cmap(c, _SP | _NL | _QF | _QB)) {	/* sp \t\n'"` */
194 	    unDgetC(c);
195 	    if (cmap(c, QUOTES))
196 		return (wp);
197 	    *wp++ = 0;
198 	    Gcat(STRNULL, wbuf);
199 	    return (NULL);
200 	}
201 	if (--i <= 0)
202 	    stderror(ERR_WTOOLONG);
203 	*wp++ = (Char)c;
204     }
205 }
206 
207 /*
208  * Get a word.  This routine is analogous to the routine
209  * word() in sh.lex.c for the main lexical input.  One difference
210  * here is that we don't get a newline to terminate our expansion.
211  * Rather, DgetC will return a DEOF when we hit the end-of-input.
212  */
213 static int
214 Dword(void)
215 {
216     Char wbuf[BUFSIZE], *wp;
217     int c, c1;
218     ptrdiff_t i;
219     int dolflg, done, sofar;
220 
221     done = 0;
222     i = MAXWLEN;
223     sofar = 0;
224     wp = wbuf;
225 
226     while (!done) {
227 	done = 1;
228 	c = DgetC(DODOL);
229 	switch (c) {
230 	case DEOF:
231 	    if (sofar == 0)
232 		return (0);
233 	    /* finish this word and catch the code above the next time */
234 	    unDredc(c);
235 	    /* FALLTHROUGH */
236 	case '\n':
237 	    *wp = 0;
238 	    Gcat(STRNULL, wbuf);
239 	    return (1);
240 	case ' ':
241 	case '\t':
242 	    done = 0;
243 	    break;
244 	case '`':
245 	    /* We preserve ` quotations which are done yet later */
246 	    *wp++ = (Char)c, --i;
247 	    /* FALLTHROUGH */
248 	case '\'':
249 	case '"':
250 	    /*
251 	     * Note that DgetC never returns a QUOTES character from an
252 	     * expansion, so only true input quotes will get us here or out.
253 	     */
254 	    c1 = c;
255 	    dolflg = c1 == '"' ? DODOL : 0;
256 	    for (;;) {
257 		c = DgetC(dolflg);
258 		if (c == c1)
259 		    break;
260 		if (c == '\n' || c == DEOF)
261 		    stderror(ERR_UNMATCHED, c1);
262 		if ((c & (QUOTE | TRIM)) == ('\n' | QUOTE))
263 		    --wp, ++i;
264 		if (--i <= 0)
265 		    stderror(ERR_WTOOLONG);
266 		switch (c1) {
267 		case '"':
268 		    /*
269 		     * Leave any `s alone for later. Other chars are all
270 		     * quoted, thus `...` can tell it was within "...".
271 		     */
272 		    *wp++ = (Char)(c == '`' ? '`' : (c | QUOTE));
273 		    break;
274 		case '\'':
275 		    /* Prevent all further interpretation */
276 		    *wp++ = (Char)(c | QUOTE);
277 		    break;
278 		case '`':
279 		    /* Leave all text alone for later */
280 		    *wp++ = (Char)c;
281 		    break;
282 		default:
283 		    break;
284 		}
285 	    }
286 	    if (c1 == '`')
287 		*wp++ = '`' /* i--; eliminated */;
288 	    sofar = 1;
289 	    if ((wp = Dpack(wbuf, wp)) == NULL)
290 		return (1);
291 	    else {
292 		i = MAXWLEN - (wp - wbuf);
293 		done = 0;
294 	    }
295 	    break;
296 	case '\\':
297 	    c = DgetC(0);	/* No $ subst! */
298 	    if (c == '\n' || c == DEOF) {
299 		done = 0;
300 		break;
301 	    }
302 	    c |= QUOTE;
303 	    break;
304 	default:
305 	    break;
306 	}
307 	if (done) {
308 	    unDgetC(c);
309 	    sofar = 1;
310 	    if ((wp = Dpack(wbuf, wp)) == NULL)
311 		return (1);
312 	    else {
313 		i = MAXWLEN - (wp - wbuf);
314 		done = 0;
315 	    }
316 	}
317     }
318     /* Really NOTREACHED */
319     return (0);
320 }
321 
322 
323 /*
324  * Get a character, performing $ substitution unless flag is 0.
325  * Any QUOTES character which is returned from a $ expansion is
326  * QUOTEd so that it will not be recognized above.
327  */
328 static int
329 DgetC(int flag)
330 {
331     int c;
332 top:
333     if ((c = Dpeekc) != '\0') {
334 	Dpeekc = 0;
335 	return (c);
336     }
337     if (lap) {
338 	c = *lap++ & (QUOTE | TRIM);
339 	if (c == 0) {
340 	    lap = 0;
341 	    goto top;
342 	}
343 quotspec:
344 	if (cmap(c, QUOTES))
345 	    return (c | QUOTE);
346 	return (c);
347     }
348     if (dolp) {
349 	if ((c = *dolp++ & (QUOTE | TRIM)) != '\0')
350 	    goto quotspec;
351 	if (dolcnt > 0) {
352 	    setDolp(*dolnxt++);
353 	    --dolcnt;
354 	    return (' ');
355 	}
356 	dolp = 0;
357     }
358     if (dolcnt > 0) {
359 	setDolp(*dolnxt++);
360 	--dolcnt;
361 	goto top;
362     }
363     c = Dredc();
364     if (c == '$' && flag) {
365 	Dgetdol();
366 	goto top;
367     }
368     return (c);
369 }
370 
371 static Char *nulvec[] = {0};
372 static struct varent nulargv = {nulvec, STRargv, { NULL, NULL, NULL }, 0};
373 
374 static void
375 dolerror(Char *s)
376 {
377     setname(vis_str(s));
378     stderror(ERR_NAME | ERR_RANGE);
379     /* NOTREACHED */
380 }
381 
382 /*
383  * Handle the multitudinous $ expansion forms.
384  * Ugh.
385  */
386 static void
387 Dgetdol(void)
388 {
389     static Char *dolbang = NULL;
390     Char name[4*MAXVARLEN+1];
391     Char wbuf[BUFSIZE];
392     struct varent *vp;
393     Char *np;
394     int c, lwb, sc, subscr, upb;
395     int dimen, bitset;
396     char tnp;
397 
398     bitset = 0;
399     dimen = 0;
400     lwb = 1;
401     upb = 0;
402     subscr = 0;
403     vp = NULL;
404 
405     dolnmod = dolmcnt = dolwcnt = 0;
406     c = sc = DgetC(0);
407     if (c == '{')
408 	c = DgetC(0);		/* sc is { to take } later */
409     if ((c & TRIM) == '#')
410 	dimen++, c = DgetC(0);	/* $# takes dimension */
411     else if (c == '?')
412 	bitset++, c = DgetC(0);	/* $? tests existence */
413     switch (c) {
414     case '!':
415 	if (dimen || bitset)
416 	    stderror(ERR_SYNTAX);
417 	if (backpid != 0) {
418 	    if (dolbang)
419 		xfree((ptr_t)dolbang);
420 	    setDolp(dolbang = putn(backpid));
421 	}
422 	goto eatbrac;
423     case '$':
424 	if (dimen || bitset)
425 	    stderror(ERR_SYNTAX);
426 	setDolp(doldol);
427 	goto eatbrac;
428     case '<' | QUOTE:
429 	if (bitset)
430 	    stderror(ERR_NOTALLOWED, "$?<");
431 	if (dimen)
432 	    stderror(ERR_NOTALLOWED, "$?#");
433 	for (np = wbuf; read(OLDSTD, &tnp, 1) == 1; np++) {
434 	    *np = (unsigned char)tnp;
435 	    if (np >= &wbuf[BUFSIZE - 1])
436 		stderror(ERR_LTOOLONG);
437 	    if (tnp == '\n')
438 		break;
439 	}
440 	*np = 0;
441 	/*
442 	 * KLUDGE: dolmod is set here because it will cause setDolp to call
443 	 * domod and thus to copy wbuf. Otherwise setDolp would use it
444 	 * directly. If we saved it ourselves, no one would know when to free
445 	 * it. The actual function of the 'q' causes filename expansion not to
446 	 * be done on the interpolated value.
447 	 */
448 	dolmod[dolnmod++] = 'q';
449 	dolmcnt = 10000;
450 	setDolp(wbuf);
451 	goto eatbrac;
452     case DEOF:
453     case '\n':
454 	stderror(ERR_SYNTAX);
455 	/* NOTREACHED */
456     case '*':
457 	(void) Strcpy(name, STRargv);
458 	vp = adrof(STRargv);
459 	subscr = -1;		/* Prevent eating [...] */
460 	break;
461     default:
462 	np = name;
463 	if (Isdigit(c)) {
464 	    if (dimen)
465 		stderror(ERR_NOTALLOWED, "$#<num>");
466 	    subscr = 0;
467 	    do {
468 		subscr = subscr * 10 + c - '0';
469 		c = DgetC(0);
470 	    } while (Isdigit(c));
471 	    unDredc(c);
472 	    if (subscr < 0)
473 		stderror(ERR_RANGE);
474 	    if (subscr == 0) {
475 		if (bitset) {
476 		    dolp = ffile ? STR1 : STR0;
477 		    goto eatbrac;
478 		}
479 		if (ffile == 0)
480 		    stderror(ERR_DOLZERO);
481 		fixDolMod();
482 		setDolp(ffile);
483 		goto eatbrac;
484 	    }
485 	    if (bitset)
486 		stderror(ERR_DOLQUEST);
487 	    vp = adrof(STRargv);
488 	    if (vp == 0) {
489 		vp = &nulargv;
490 		goto eatmod;
491 	    }
492 	    break;
493 	}
494 	if (!alnum(c))
495 	    stderror(ERR_VARALNUM);
496 	for (;;) {
497 	    *np++ = (Char)c;
498 	    c = DgetC(0);
499 	    if (!alnum(c))
500 		break;
501 	    if (np >= &name[MAXVARLEN])
502 		stderror(ERR_VARTOOLONG);
503 	}
504 	*np++ = 0;
505 	unDredc(c);
506 	vp = adrof(name);
507     }
508     if (bitset) {
509 	dolp = (vp || getenv(short2str(name))) ? STR1 : STR0;
510 	goto eatbrac;
511     }
512     if (vp == 0) {
513 	np = str2short(getenv(short2str(name)));
514 	if (np) {
515 	    fixDolMod();
516 	    setDolp(np);
517 	    goto eatbrac;
518 	}
519 	udvar(name);
520     }
521     c = DgetC(0);
522     upb = blklen(vp->vec);
523     if (dimen == 0 && subscr == 0 && c == '[') {
524 	np = name;
525 	for (;;) {
526 	    c = DgetC(DODOL);	/* Allow $ expand within [ ] */
527 	    if (c == ']')
528 		break;
529 	    if (c == '\n' || c == DEOF)
530 		stderror(ERR_INCBR);
531 	    if (np >= &name[sizeof(name) / sizeof(Char) - 2])
532 		stderror(ERR_VARTOOLONG);
533 	    *np++ = (Char)c;
534 	}
535 	*np = 0, np = name;
536 	if (dolp || dolcnt)	/* $ exp must end before ] */
537 	    stderror(ERR_EXPORD);
538 	if (!*np)
539 	    stderror(ERR_SYNTAX);
540 	if (Isdigit(*np)) {
541 	    int     i;
542 
543 	    for (i = 0; Isdigit(*np); i = i * 10 + *np++ - '0')
544 		continue;
545 	    if ((i < 0 || i > upb) && !any("-*", *np)) {
546 		dolerror(vp->v_name);
547 		return;
548 	    }
549 	    lwb = i;
550 	    if (!*np)
551 		upb = lwb, np = STRstar;
552 	}
553 	if (*np == '*')
554 	    np++;
555 	else if (*np != '-')
556 	    stderror(ERR_MISSING, '-');
557 	else {
558 	    int i = upb;
559 
560 	    np++;
561 	    if (Isdigit(*np)) {
562 		i = 0;
563 		while (Isdigit(*np))
564 		    i = i * 10 + *np++ - '0';
565 		if (i < 0 || i > upb) {
566 		    dolerror(vp->v_name);
567 		    return;
568 		}
569 	    }
570 	    if (i < lwb)
571 		upb = lwb - 1;
572 	    else
573 		upb = i;
574 	}
575 	if (lwb == 0) {
576 	    if (upb != 0) {
577 		dolerror(vp->v_name);
578 		return;
579 	    }
580 	    upb = -1;
581 	}
582 	if (*np)
583 	    stderror(ERR_SYNTAX);
584     }
585     else {
586 	if (subscr > 0) {
587 	    if (subscr > upb)
588 		lwb = 1, upb = 0;
589 	    else
590 		lwb = upb = subscr;
591 	}
592 	unDredc(c);
593     }
594     if (dimen) {
595 	Char   *cp = putn(upb - lwb + 1);
596 
597 	addla(cp);
598 	xfree((ptr_t) cp);
599     }
600     else {
601 eatmod:
602 	fixDolMod();
603 	dolnxt = &vp->vec[lwb - 1];
604 	dolcnt = upb - lwb + 1;
605     }
606 eatbrac:
607     if (sc == '{') {
608 	c = Dredc();
609 	if (c != '}')
610 	    stderror(ERR_MISSING, '}');
611     }
612 }
613 
614 static void
615 fixDolMod(void)
616 {
617     int c;
618 
619     c = DgetC(0);
620     if (c == ':') {
621 	do {
622 	    c = DgetC(0), dolmcnt = 1, dolwcnt = 1;
623 	    if (c == 'g' || c == 'a') {
624 		if (c == 'g')
625 		    dolmcnt = 10000;
626 		else
627 		    dolwcnt = 10000;
628 		c = DgetC(0);
629 	    }
630 	    if ((c == 'g' && dolmcnt != 10000) ||
631 		(c == 'a' && dolwcnt != 10000)) {
632 		if (c == 'g')
633 		    dolmcnt = 10000;
634 		else
635 		    dolwcnt = 10000;
636 		c = DgetC(0);
637 	    }
638 
639 	    if (c == 's') {	/* [eichin:19910926.0755EST] */
640 		int delimcnt = 2;
641 		int delim = DgetC(0);
642 		dolmod[dolnmod++] = (Char)c;
643 		dolmod[dolnmod++] = (Char)delim;
644 
645 		if (!delim || letter(delim)
646 		    || Isdigit(delim) || any(" \t\n", delim)) {
647 		    seterror(ERR_BADSUBST);
648 		    break;
649 		}
650 		while ((c = DgetC(0)) != (-1)) {
651 		    dolmod[dolnmod++] = (Char)c;
652 		    if(c == delim) delimcnt--;
653 		    if(!delimcnt) break;
654 		}
655 		if(delimcnt) {
656 		    seterror(ERR_BADSUBST);
657 		    break;
658 		}
659 		continue;
660 	    }
661 	    if (!any("htrqxes", c))
662 		stderror(ERR_BADMOD, c);
663 	    dolmod[dolnmod++] = (Char)c;
664 	    if (c == 'q')
665 		dolmcnt = 10000;
666 	}
667 	while ((c = DgetC(0)) == ':');
668 	unDredc(c);
669     }
670     else
671 	unDredc(c);
672 }
673 
674 static void
675 setDolp(Char *cp)
676 {
677     Char *dp;
678     int i;
679 
680     if (dolnmod == 0 || dolmcnt == 0) {
681 	dolp = cp;
682 	return;
683     }
684     dp = cp = Strsave(cp);
685     for (i = 0; i < dolnmod; i++) {
686 	/* handle s// [eichin:19910926.0510EST] */
687 	if(dolmod[i] == 's') {
688 	    int delim;
689 	    Char *lhsub, *rhsub, *np;
690 	    size_t lhlen = 0, rhlen = 0;
691 	    int didmod = 0;
692 
693 	    delim = dolmod[++i];
694 	    if (!delim || letter(delim)
695 		|| Isdigit(delim) || any(" \t\n", delim)) {
696 		seterror(ERR_BADSUBST);
697 		break;
698 	    }
699 	    lhsub = &dolmod[++i];
700 	    while(dolmod[i] != delim && dolmod[++i]) {
701 		lhlen++;
702 	    }
703 	    dolmod[i] = 0;
704 	    rhsub = &dolmod[++i];
705 	    while(dolmod[i] != delim && dolmod[++i]) {
706 		rhlen++;
707 	    }
708 	    dolmod[i] = 0;
709 
710 	    do {
711 		dp = Strstr(cp, lhsub);
712 		if (dp) {
713 		    np = xmalloc(
714 		        (size_t)((Strlen(cp) + 1 - lhlen + rhlen) *
715 		        sizeof(*np)));
716 		    (void)Strncpy(np, cp, (size_t)(dp - cp));
717 		    (void)Strcpy(np + (dp - cp), rhsub);
718 		    (void)Strcpy(np + (dp - cp) + rhlen, dp + lhlen);
719 
720 		    xfree((ptr_t) cp);
721 		    dp = cp = np;
722 		    didmod = 1;
723 		} else {
724 		    /* should this do a seterror? */
725 		    break;
726 		}
727 	    }
728 	    while (dolwcnt == 10000);
729 	    /*
730 	     * restore dolmod for additional words
731 	     */
732 	    dolmod[i] = rhsub[-1] = (Char)delim;
733 	    if (didmod)
734 		dolmcnt--;
735 	    else
736 		break;
737         } else {
738 	    int didmod = 0;
739 
740 	    do {
741 		if ((dp = domod(cp, dolmod[i]))) {
742 		    didmod = 1;
743 		    if (Strcmp(cp, dp) == 0) {
744 			xfree((ptr_t) cp);
745 			cp = dp;
746 			break;
747 		    }
748 		    else {
749 			xfree((ptr_t) cp);
750 			cp = dp;
751 		    }
752 		}
753 		else
754 		    break;
755 	    }
756 	    while (dolwcnt == 10000);
757 	    dp = cp;
758 	    if (didmod)
759 		dolmcnt--;
760 	    else
761 		break;
762 	}
763     }
764 
765     if (dp) {
766 	addla(dp);
767 	xfree((ptr_t) dp);
768     }
769     else {
770 	addla(cp);
771 	xfree((ptr_t) cp);
772     }
773 
774     dolp = STRNULL;
775     if (seterr)
776 	stderror(ERR_OLD);
777 }
778 
779 static void
780 unDredc(int c)
781 {
782     Dpeekrd = c;
783 }
784 
785 static int
786 Dredc(void)
787 {
788     int c;
789 
790     if ((c = Dpeekrd) != '\0') {
791 	Dpeekrd = 0;
792 	return (c);
793     }
794     if (Dcp && (c = *Dcp++))
795 	return (c & (QUOTE | TRIM));
796     if (*Dvp == 0) {
797 	Dcp = 0;
798 	return (DEOF);
799     }
800     Dcp = *Dvp++;
801     return (' ');
802 }
803 
804 static void
805 Dtestq(int c)
806 {
807     if (cmap(c, QUOTES))
808 	gflag = 1;
809 }
810 
811 /*
812  * Form a shell temporary file (in unit 0) from the words
813  * of the shell input up to EOF or a line the same as "term".
814  * Unit 0 should have been closed before this call.
815  */
816 void
817 /*ARGSUSED*/
818 heredoc(Char *term)
819 {
820     Char obuf[BUFSIZE], lbuf[BUFSIZE], mbuf[BUFSIZE];
821     struct timespec tv;
822     Char *Dv[2], *lbp, *obp, *mbp, **vp;
823     char *tmp;
824     int c, ocnt, lcnt, mcnt;
825     int quoted;
826 
827 again:
828     tmp = short2str(shtemp);
829     if (open(tmp, O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600) < 0) {
830 	if (errno == EEXIST) {
831 	    if (unlink(tmp) == -1) {
832 		(void)clock_gettime(CLOCK_MONOTONIC, &tv);
833 		mbp = putn((((int)tv.tv_sec) ^
834 		    ((int)tv.tv_nsec) ^ ((int)getpid())) & 0x00ffffff);
835 		shtemp = Strspl(STRtmpsh, mbp);
836 		xfree((ptr_t)mbp);
837 	    }
838 	    goto again;
839 	}
840 	stderror(ERR_SYSTEM, tmp, strerror(errno));
841     }
842     (void)unlink(tmp);		/* 0 0 inode! */
843     Dv[0] = term;
844     Dv[1] = NULL;
845     gflag = 0;
846     trim(Dv);
847     rscan(Dv, Dtestq);
848     quoted = gflag;
849     ocnt = BUFSIZE;
850     obp = obuf;
851     for (;;) {
852 	/*
853 	 * Read up a line
854 	 */
855 	lbp = lbuf;
856 	lcnt = BUFSIZE - 4;
857 	for (;;) {
858 	    c = readc(1);	/* 1 -> Want EOF returns */
859 	    if (c < 0 || c == '\n')
860 		break;
861 	    if ((c &= TRIM) != '\0') {
862 		*lbp++ = (Char)c;
863 		if (--lcnt < 0) {
864 		    setname("<<");
865 		    stderror(ERR_NAME | ERR_OVERFLOW);
866 		}
867 	    }
868 	}
869 	*lbp = 0;
870 
871 	/*
872 	 * Check for EOF or compare to terminator -- before expansion
873 	 */
874 	if (c < 0 || eq(lbuf, term)) {
875 	    (void)write(0, short2str(obuf), (size_t)(BUFSIZE - ocnt));
876 	    (void)lseek(0, (off_t)0, SEEK_SET);
877 	    return;
878 	}
879 
880 	/*
881 	 * If term was quoted or -n just pass it on
882 	 */
883 	if (quoted || noexec) {
884 	    *lbp++ = '\n';
885 	    *lbp = 0;
886 	    for (lbp = lbuf; (c = *lbp++) != '\0';) {
887 		*obp++ = (Char)c;
888 		if (--ocnt == 0) {
889 		    (void) write(0, short2str(obuf), BUFSIZE);
890 		    obp = obuf;
891 		    ocnt = BUFSIZE;
892 		}
893 	    }
894 	    continue;
895 	}
896 
897 	/*
898 	 * Term wasn't quoted so variable and then command expand the input
899 	 * line
900 	 */
901 	Dcp = lbuf;
902 	Dvp = Dv + 1;
903 	mbp = mbuf;
904 	mcnt = BUFSIZE - 4;
905 	for (;;) {
906 	    c = DgetC(DODOL);
907 	    if (c == DEOF)
908 		break;
909 	    if ((c &= TRIM) == 0)
910 		continue;
911 	    /* \ quotes \ $ ` here */
912 	    if (c == '\\') {
913 		c = DgetC(0);
914 		if (!any("$\\`", c))
915 		    unDgetC(c | QUOTE), c = '\\';
916 		else
917 		    c |= QUOTE;
918 	    }
919 	    *mbp++ = (Char)c;
920 	    if (--mcnt == 0) {
921 		setname("<<");
922 		stderror(ERR_NAME | ERR_OVERFLOW);
923 	    }
924 	}
925 	*mbp++ = 0;
926 
927 	/*
928 	 * If any ` in line do command substitution
929 	 */
930 	mbp = mbuf;
931 	if (any(short2str(mbp), '`')) {
932 	    /*
933 	     * 1 arg to dobackp causes substitution to be literal. Words are
934 	     * broken only at newlines so that all blanks and tabs are
935 	     * preserved.  Blank lines (null words) are not discarded.
936 	     */
937 	    vp = dobackp(mbuf, 1);
938 	}
939 	else
940 	    /* Setup trivial vector similar to return of dobackp */
941 	    Dv[0] = mbp, Dv[1] = NULL, vp = Dv;
942 
943 	/*
944 	 * Resurrect the words from the command substitution each separated by
945 	 * a newline.  Note that the last newline of a command substitution
946 	 * will have been discarded, but we put a newline after the last word
947 	 * because this represents the newline after the last input line!
948 	 */
949 	for (; *vp; vp++) {
950 	    for (mbp = *vp; *mbp; mbp++) {
951 		*obp++ = *mbp & TRIM;
952 		if (--ocnt == 0) {
953 		    (void)write(0, short2str(obuf), BUFSIZE);
954 		    obp = obuf;
955 		    ocnt = BUFSIZE;
956 		}
957 	    }
958 	    *obp++ = '\n';
959 	    if (--ocnt == 0) {
960 		(void)write(0, short2str(obuf), BUFSIZE);
961 		obp = obuf;
962 		ocnt = BUFSIZE;
963 	    }
964 	}
965 	if (pargv)
966 	    blkfree(pargv), pargv = 0;
967     }
968 }
969