xref: /titanic_41/usr/src/lib/libshell/common/sh/array.c (revision e9af4bc0b1cc30cea75d6ad4aa2fde97d985e9be)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1982-2009 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                  David Korn <dgk@research.att.com>                   *
18 *                                                                      *
19 ***********************************************************************/
20 #pragma prototyped
21 /*
22  * Array processing routines
23  *
24  *   David Korn
25  *   AT&T Labs
26  *   dgk@research.att.com
27  *
28  */
29 
30 #include	"defs.h"
31 #include	<stak.h>
32 #include	"name.h"
33 
34 #define NUMSIZE	(4+(ARRAY_MAX>999)+(ARRAY_MAX>9999)+(ARRAY_MAX>99999))
35 #define is_associative(ap)	array_assoc((Namarr_t*)(ap))
36 #define array_setbit(cp, n, b)	(cp[n] |= (b))
37 #define array_clrbit(cp, n, b)	(cp[n] &= ~(b))
38 #define array_isbit(cp, n, b)	(cp[n] & (b))
39 #define NV_CHILD		NV_EXPORT
40 #define ARRAY_CHILD		1
41 #define ARRAY_NOFREE		2
42 
43 struct index_array
44 {
45         Namarr_t        header;
46 	void		*xp;	/* if set, subscripts will be converted */
47         int		cur;    /* index of current element */
48         int		maxi;   /* maximum index for array */
49 	unsigned char	*bits;	/* bit array for child subscripts */
50         union Value	val[1]; /* array of value holders */
51 };
52 
53 struct assoc_array
54 {
55 	Namarr_t	header;
56 	Namval_t	*pos;
57 	Namval_t	*nextpos;
58 	Namval_t	*cur;
59 };
60 
61 static Namarr_t *array_scope(Namval_t *np, Namarr_t *ap, int flags)
62 {
63 	Namarr_t *aq;
64 	struct index_array *ar;
65 	size_t size = ap->hdr.dsize;
66 	if(size==0)
67 		size = ap->hdr.disc->dsize;
68         if(!(aq=newof(NIL(Namarr_t*),Namarr_t,1,size-sizeof(Namarr_t))))
69                 return(0);
70         memcpy(aq,ap,size);
71 	aq->hdr.nofree &= ~1;
72         aq->hdr.nofree |= (flags&NV_RDONLY)?1:0;
73 	if(is_associative(aq))
74 	{
75 		aq->scope = (void*)dtopen(&_Nvdisc,Dtoset);
76 		dtview((Dt_t*)aq->scope,aq->table);
77 		aq->table = (Dt_t*)aq->scope;
78 		return(aq);
79 	}
80 	aq->scope = (void*)ap;
81 	ar = (struct index_array*)aq;
82 	memset(ar->val, 0, ar->maxi*sizeof(char*));
83 	return(aq);
84 }
85 
86 static int array_unscope(Namval_t *np,Namarr_t *ap)
87 {
88 	Namfun_t *fp;
89 	if(!ap->scope)
90 		return(0);
91 	if(is_associative(ap))
92 		(*ap->fun)(np, NIL(char*), NV_AFREE);
93 	if((fp = nv_disc(np,(Namfun_t*)ap,NV_POP)) && !(fp->nofree&1))
94 		free((void*)fp);
95 	nv_delete(np,(Dt_t*)0,0);
96 	return(1);
97 }
98 
99 static void array_syncsub(Namarr_t *ap, Namarr_t *aq)
100 {
101 	((struct index_array*)ap)->cur = ((struct index_array*)aq)->cur;
102 }
103 
104 static int array_covered(Namval_t *np, struct index_array *ap)
105 {
106 	struct index_array *aq = (struct index_array*)ap->header.scope;
107 	if(!ap->header.fun && aq)
108 		return ((ap->cur<aq->maxi) && aq->val[ap->cur].cp);
109 	return(0);
110 }
111 
112 /*
113  * replace discipline with new one
114  */
115 static void array_setptr(register Namval_t *np, struct index_array *old, struct index_array *new)
116 {
117 	register Namfun_t **fp = &np->nvfun;
118 	while(*fp && *fp!= &old->header.hdr)
119 		fp = &((*fp)->next);
120 	if(*fp)
121 	{
122 		new->header.hdr.next = (*fp)->next;
123 		*fp = &new->header.hdr;
124 	}
125 	else sfprintf(sfstderr,"discipline not replaced\n");
126 }
127 
128 /*
129  *   Calculate the amount of space to be allocated to hold an
130  *   indexed array into which <maxi> is a legal index.  The number of
131  *   elements that will actually fit into the array (> <maxi>
132  *   but <= ARRAY_MAX) is returned.
133  *
134  */
135 static int	arsize(struct index_array *ap, register int maxi)
136 {
137 	if(ap && maxi < 2*ap->maxi)
138 		maxi = 2*ap->maxi;
139 	maxi = roundof(maxi,ARRAY_INCR);
140 	return (maxi>ARRAY_MAX?ARRAY_MAX:maxi);
141 }
142 
143 static struct index_array *array_grow(Namval_t*, struct index_array*,int);
144 
145 /* return index of highest element of an array */
146 int array_maxindex(Namval_t *np)
147 {
148 	register struct index_array *ap = (struct index_array*)nv_arrayptr(np);
149 	register int i = ap->maxi;
150 	if(is_associative(ap))
151 		return(-1);
152 	while(i>0 && ap->val[--i].cp==0);
153 	return(i+1);
154 }
155 
156 static union Value *array_getup(Namval_t *np, Namarr_t *arp, int update)
157 {
158 	register struct index_array *ap = (struct index_array*)arp;
159 	register union Value *up;
160 	int	nofree;
161 	if(!arp)
162 		return(&np->nvalue);
163 	if(is_associative(ap))
164 	{
165 		Namval_t	*mp;
166 		mp = (Namval_t*)((*arp->fun)(np,NIL(char*),NV_ACURRENT));
167 		if(mp)
168 		{
169 			nofree = nv_isattr(mp,NV_NOFREE);
170 			up = &mp->nvalue;
171 		}
172 		else
173 			return((union Value*)((*arp->fun)(np,NIL(char*),0)));
174 	}
175 	else
176 	{
177 		if(ap->cur >= ap->maxi)
178 			errormsg(SH_DICT,ERROR_exit(1),e_subscript,nv_name(np));
179 		up = &(ap->val[ap->cur]);
180 		nofree = array_isbit(ap->bits,ap->cur,ARRAY_NOFREE);
181 	}
182 	if(update)
183 	{
184 		if(nofree)
185 			nv_onattr(np,NV_NOFREE);
186 		else
187 			nv_offattr(np,NV_NOFREE);
188 	}
189 	return(up);
190 }
191 
192 int nv_arrayisset(Namval_t *np, Namarr_t *arp)
193 {
194 	register struct index_array *ap = (struct index_array*)arp;
195 	union Value *up;
196 	if(is_associative(ap))
197 		return((np = nv_opensub(np)) && !nv_isnull(np));
198 	if(ap->cur >= ap->maxi)
199 		return(0);
200 	up = &(ap->val[ap->cur]);
201 	return(up->cp && up->cp!=Empty);
202 }
203 
204 /*
205  * Get the Value pointer for an array.
206  * Delete space as necessary if flag is ARRAY_DELETE
207  * After the lookup is done the last @ or * subscript is incremented
208  */
209 static Namval_t *array_find(Namval_t *np,Namarr_t *arp, int flag)
210 {
211 	register struct index_array *ap = (struct index_array*)arp;
212 	register union Value	*up;
213 	Namval_t		*mp;
214 	int			wasundef;
215 	if(flag&ARRAY_LOOKUP)
216 		ap->header.nelem &= ~ARRAY_NOSCOPE;
217 	else
218 		ap->header.nelem |= ARRAY_NOSCOPE;
219 	if(wasundef = ap->header.nelem&ARRAY_UNDEF)
220 	{
221 		ap->header.nelem &= ~ARRAY_UNDEF;
222 		/* delete array is the same as delete array[@] */
223 		if(flag&ARRAY_DELETE)
224 		{
225 			nv_putsub(np, NIL(char*), ARRAY_SCAN|ARRAY_NOSCOPE);
226 			ap->header.nelem |= ARRAY_SCAN;
227 		}
228 		else /* same as array[0] */
229 		{
230 			if(is_associative(ap))
231 				(*ap->header.fun)(np,"0",flag==ARRAY_ASSIGN?NV_AADD:0);
232 			else
233 				ap->cur = 0;
234 		}
235 	}
236 	if(is_associative(ap))
237 	{
238 		mp = (Namval_t*)((*arp->fun)(np,NIL(char*),NV_ACURRENT));
239 		if(!mp)
240 			up = (union Value*)&mp;
241 		else if(nv_isarray(mp))
242 		{
243 			if(wasundef)
244 				nv_putsub(mp,NIL(char*),ARRAY_UNDEF);
245 			return(mp);
246 		}
247 		else
248 		{
249 			up =  &mp->nvalue;
250 			if(nv_isvtree(mp))
251 			{
252 				if(!up->cp && flag==ARRAY_ASSIGN)
253 				{
254 					nv_arraychild(np,mp,0);
255 					ap->header.nelem++;
256 				}
257 				return(mp);
258 			}
259 		}
260 	}
261 	else
262 	{
263 		if(!(ap->header.nelem&ARRAY_SCAN) && ap->cur >= ap->maxi)
264 			ap = array_grow(np, ap, (int)ap->cur);
265 		if(ap->cur>=ap->maxi)
266 			errormsg(SH_DICT,ERROR_exit(1),e_subscript,nv_name(np));
267 		up = &(ap->val[ap->cur]);
268 		if((!up->cp||up->cp==Empty) && nv_type(np) && nv_isvtree(np))
269 		{
270 			char *cp;
271 			if(!ap->header.table)
272 				ap->header.table = dtopen(&_Nvdisc,Dtoset);
273 			sfprintf(sh.strbuf,"%d",ap->cur);
274 			cp = sfstruse(sh.strbuf);
275 			mp = nv_search(cp, ap->header.table, NV_ADD);
276 			mp->nvenv = (char*)np;
277 			nv_arraychild(np,mp,0);
278 		}
279 		if(up->np && array_isbit(ap->bits,ap->cur,ARRAY_CHILD))
280 		{
281 			if(wasundef && nv_isarray(up->np))
282 				nv_putsub(up->np,NIL(char*),ARRAY_UNDEF);
283 			return(up->np);
284 		}
285 	}
286 	np->nvalue.cp = up->cp;
287 	if(!up->cp)
288 	{
289 		if(flag!=ARRAY_ASSIGN)
290 			return(0);
291 		if(!array_covered(np,ap))
292 			ap->header.nelem++;
293 	}
294 	return(np);
295 }
296 
297 #if SHOPT_TYPEDEF
298 int nv_arraysettype(Namval_t *np, Namval_t *tp, const char *sub, int flags)
299 {
300 	Namval_t	*nq;
301 	char		*av[2];
302 	int		rdonly = nv_isattr(np,NV_RDONLY);
303 	int		xtrace = sh_isoption(SH_XTRACE);
304 	Namarr_t	*ap = nv_arrayptr(np);
305 	av[1] = 0;
306 	sh.last_table = 0;
307 	if(!ap->table)
308 		ap->table = dtopen(&_Nvdisc,Dtoset);
309 	if(nq = nv_search(sub, ap->table, NV_ADD))
310 	{
311 		if(!nq->nvfun && nq->nvalue.cp && *nq->nvalue.cp==0)
312 			_nv_unset(nq,NV_RDONLY);
313 		nv_arraychild(np,nq,0);
314 		if(!nv_isattr(tp,NV_BINARY))
315 		{
316 			sfprintf(sh.strbuf,"%s=%s",nv_name(nq),nv_getval(np));
317 			av[0] = strdup(sfstruse(sh.strbuf));
318 		}
319 		if(!nv_clone(tp,nq,flags|NV_NOFREE))
320 			return(0);
321 		ap->nelem |= ARRAY_SCAN;
322 		if(!rdonly)
323 			nv_offattr(nq,NV_RDONLY);
324 		if(!nv_isattr(tp,NV_BINARY))
325 		{
326 			if(xtrace)
327 				sh_offoption(SH_XTRACE);
328 			ap->nelem &= ~ARRAY_SCAN;
329 			sh_eval(sh_sfeval(av),0);
330 			ap->nelem |= ARRAY_SCAN;
331 			free((void*)av[0]);
332 			if(xtrace)
333 				sh_onoption(SH_XTRACE);
334 		}
335 		return(1);
336 	}
337 	return(0);
338 }
339 #endif /* SHOPT_TYPEDEF */
340 
341 
342 static Namfun_t *array_clone(Namval_t *np, Namval_t *mp, int flags, Namfun_t *fp)
343 {
344 	Namarr_t		*ap = (Namarr_t*)fp;
345 	Namval_t		*nq, *mq;
346 	char			*name, *sub=0;
347 	int			nelem, skipped=0;
348 	Dt_t			*otable=ap->table;
349 	struct index_array	*aq = (struct index_array*)ap, *ar;
350 	Shell_t			*shp = sh_getinterp();
351 	if(flags&NV_MOVE)
352 	{
353 		if((flags&NV_COMVAR) && nv_putsub(np,NIL(char*),ARRAY_SCAN))
354 		{
355 			do
356 			{
357 				if(nq=nv_opensub(np))
358 					nq->nvenv = (void*)mp;
359 			}
360 			while(nv_nextsub(np));
361 		}
362 		return(fp);
363 	}
364 	nelem = ap->nelem;
365 	if(nelem&ARRAY_NOCLONE)
366 		return(0);
367 	if((flags&NV_TYPE) && !ap->scope)
368 	{
369 		ap = array_scope(np,ap,flags);
370 		return(&ap->hdr);
371 	}
372 	ap = (Namarr_t*)nv_clone_disc(fp,0);
373 	if(flags&NV_COMVAR)
374 	{
375 		ap->scope = 0;
376 		ap->nelem = 0;
377 		sh.prev_table = sh.last_table;
378 		sh.prev_root = sh.last_root;
379 	}
380 	if(ap->table)
381 	{
382 		ap->table = dtopen(&_Nvdisc,Dtoset);
383 		if(ap->scope && !(flags&NV_COMVAR))
384 		{
385 			ap->scope = ap->table;
386 			dtview(ap->table, otable->view);
387 		}
388 	}
389 	mp->nvfun = (Namfun_t*)ap;
390 	mp->nvflag &= NV_MINIMAL;
391 	mp->nvflag |= (np->nvflag&~(NV_MINIMAL|NV_NOFREE));
392 	if(!(nelem&(ARRAY_SCAN|ARRAY_UNDEF)) && (sub=nv_getsub(np)))
393 		sub = strdup(sub);
394 	ar = (struct index_array*)ap;
395 	if(!is_associative(ap))
396 		ar->bits = (unsigned char*)&ar->val[ar->maxi];
397 	if(!nv_putsub(np,NIL(char*),ARRAY_SCAN|((flags&NV_COMVAR)?0:ARRAY_NOSCOPE)))
398 	{
399 		if(ap->fun)
400 			(*ap->fun)(np,(char*)np,0);
401 		skipped=1;
402 		goto skip;
403 	}
404 	do
405 	{
406 		name = nv_getsub(np);
407 		nv_putsub(mp,name,ARRAY_ADD|ARRAY_NOSCOPE);
408 		mq = 0;
409 		if(nq=nv_opensub(np))
410 			mq = nv_search(name,ap->table,NV_ADD);
411 		if(nq && (flags&NV_COMVAR) && nv_isvtree(nq))
412 		{
413 			mq->nvalue.cp = 0;
414 			if(!is_associative(ap))
415 				ar->val[ar->cur].np = mq;
416 			nv_clone(nq,mq,flags);
417 		}
418 		else if(flags&NV_ARRAY)
419 		{
420 			if((flags&NV_NOFREE) && !is_associative(ap))
421 				array_setbit(aq->bits,aq->cur,ARRAY_NOFREE);
422 			else if(nq && (flags&NV_NOFREE))
423 			{
424 				mq->nvalue = nq->nvalue;
425 				nv_onattr(nq,NV_NOFREE);
426 			}
427 		}
428 		else if(nv_isattr(np,NV_INTEGER))
429 		{
430 			Sfdouble_t d= nv_getnum(np);
431 			if(!is_associative(ap))
432 				ar->val[ar->cur].cp = 0;
433 			nv_putval(mp,(char*)&d,NV_LDOUBLE);
434 		}
435 		else
436 		{
437 			if(!is_associative(ap))
438 				ar->val[ar->cur].cp = 0;
439 			nv_putval(mp,nv_getval(np),NV_RDONLY);
440 		}
441 		aq->header.nelem |= ARRAY_NOSCOPE;
442 	}
443 	while(nv_nextsub(np));
444 skip:
445 	if(sub)
446 	{
447 		if(!skipped)
448 			nv_putsub(np,sub,0L);
449 		free((void*)sub);
450 	}
451 	aq->header.nelem = ap->nelem = nelem;
452 	return(&ap->hdr);
453 }
454 
455 static char *array_getval(Namval_t *np, Namfun_t *disc)
456 {
457 	register Namarr_t *aq,*ap = (Namarr_t*)disc;
458 	register Namval_t *mp;
459 	if((mp=array_find(np,ap,ARRAY_LOOKUP))!=np)
460 	{
461 		if(!mp && !is_associative(ap) && (aq=(Namarr_t*)ap->scope))
462 		{
463 			array_syncsub(aq,ap);
464 			if((mp=array_find(np,aq,ARRAY_LOOKUP))==np)
465 				return(nv_getv(np,&aq->hdr));
466 		}
467 		return(mp?nv_getval(mp):0);
468 	}
469 	return(nv_getv(np,&ap->hdr));
470 }
471 
472 static Sfdouble_t array_getnum(Namval_t *np, Namfun_t *disc)
473 {
474 	register Namarr_t *aq,*ap = (Namarr_t*)disc;
475 	register Namval_t *mp;
476 	if((mp=array_find(np,ap,ARRAY_LOOKUP))!=np)
477 	{
478 		if(!mp && !is_associative(ap) && (aq=(Namarr_t*)ap->scope))
479 		{
480 			array_syncsub(aq,ap);
481 			if((mp=array_find(np,aq,ARRAY_LOOKUP))==np)
482 				return(nv_getn(np,&aq->hdr));
483 		}
484 		return(mp?nv_getnum(mp):0);
485 	}
486 	return(nv_getn(np,&ap->hdr));
487 }
488 
489 static void array_putval(Namval_t *np, const char *string, int flags, Namfun_t *dp)
490 {
491 	register Namarr_t	*ap = (Namarr_t*)dp;
492 	register union Value	*up;
493 	register Namval_t	*mp;
494 	register struct index_array *aq = (struct index_array*)ap;
495 	int			scan,nofree = nv_isattr(np,NV_NOFREE);
496 	do
497 	{
498 		mp = array_find(np,ap,string?ARRAY_ASSIGN:ARRAY_DELETE);
499 		scan = ap->nelem&ARRAY_SCAN;
500 		if(mp && mp!=np)
501 		{
502 			if(!is_associative(ap) && string && !(flags&NV_APPEND) && !nv_type(np) && nv_isvtree(mp))
503 			{
504 				if(!nv_isattr(np,NV_NOFREE))
505 					_nv_unset(mp,flags&NV_RDONLY);
506 				array_clrbit(aq->bits,aq->cur,ARRAY_CHILD);
507 				aq->val[aq->cur].cp = 0;
508 				if(!nv_isattr(mp,NV_NOFREE))
509 					nv_delete(mp,ap->table,0);
510 				goto skip;
511 			}
512 			nv_putval(mp, string, flags);
513 			if(string)
514 			{
515 #if SHOPT_TYPEDEF
516 				if(ap->hdr.type && ap->hdr.type!=nv_type(mp))
517 					nv_arraysettype(np,ap->hdr.type,nv_getsub(np),0);
518 #endif /* SHOPT_TYPEDEF */
519 				continue;
520 			}
521 			ap->nelem |= scan;
522 		}
523 		if(!string)
524 		{
525 			if(mp)
526 			{
527 				if(is_associative(ap))
528 				{
529 					(*ap->fun)(np,NIL(char*),NV_ADELETE);
530 					np->nvalue.cp = 0;
531 				}
532 				else
533 				{
534 					if(mp!=np)
535 					{
536 						array_clrbit(aq->bits,aq->cur,ARRAY_CHILD);
537 						aq->val[aq->cur].cp = 0;
538 						nv_delete(mp,ap->table,0);
539 					}
540 					if(!array_covered(np,(struct index_array*)ap))
541 						ap->nelem--;
542 				}
543 			}
544 			if(array_elem(ap)==0 && (ap->nelem&ARRAY_SCAN))
545 			{
546 				if(is_associative(ap))
547 					(*ap->fun)(np, NIL(char*), NV_AFREE);
548 				else if(ap->table)
549 					dtclose(ap->table);
550 				nv_offattr(np,NV_ARRAY);
551 			}
552 			if(!mp || mp!=np || is_associative(ap))
553 				continue;
554 		}
555 	skip:
556 		/* prevent empty string from being deleted */
557 		up = array_getup(np,ap,!nofree);
558 		if(up->cp ==  Empty)
559 			up->cp = 0;
560 		if(nv_isarray(np))
561 			np->nvalue.up = up;
562 		nv_putv(np,string,flags,&ap->hdr);
563 		if(!is_associative(ap))
564 		{
565 			if(string)
566 				array_clrbit(aq->bits,aq->cur,ARRAY_NOFREE);
567 			else if(mp==np)
568 				aq->val[aq->cur].cp = 0;
569 		}
570 #if SHOPT_TYPEDEF
571 		if(string && ap->hdr.type && nv_isvtree(np))
572 			nv_arraysettype(np,ap->hdr.type,nv_getsub(np),0);
573 #endif /* SHOPT_TYPEDEF */
574 	}
575 	while(!string && nv_nextsub(np));
576 	if(ap)
577 		ap->nelem &= ~ARRAY_NOSCOPE;
578 	if(nofree)
579 		nv_onattr(np,NV_NOFREE);
580 	else
581 		nv_offattr(np,NV_NOFREE);
582 	if(!string && !nv_isattr(np,NV_ARRAY))
583 	{
584 		Namfun_t *nfp;
585 		if(!is_associative(ap) && aq->xp)
586 		{
587 			_nv_unset(nv_namptr(aq->xp,0),NV_RDONLY);
588 			free((void*)aq->xp);
589 		}
590 		if((nfp = nv_disc(np,(Namfun_t*)ap,NV_POP)) && !(nfp->nofree&1))
591 			free((void*)nfp);
592 		if(!nv_isnull(np))
593 		{
594 			nv_onattr(np,NV_NOFREE);
595 			_nv_unset(np,flags);
596 		}
597 		if(np->nvalue.cp==Empty)
598 			np->nvalue.cp = 0;
599 	}
600 	if(!string && (flags&NV_TYPE))
601 		array_unscope(np,ap);
602 }
603 
604 static const Namdisc_t array_disc =
605 {
606 	sizeof(Namarr_t),
607 	array_putval,
608 	array_getval,
609 	array_getnum,
610 	0,
611 	0,
612 	array_clone
613 };
614 
615 static void array_copytree(Namval_t *np, Namval_t *mp)
616 {
617 	Namfun_t	*fp = nv_disc(np,NULL,NV_POP);
618 	nv_offattr(np,NV_ARRAY);
619 	nv_clone(np,mp,0);
620 	if(np->nvalue.cp && !nv_isattr(np,NV_NOFREE))
621 		free((void*)np->nvalue.cp);
622 	np->nvalue.cp = 0;
623 	np->nvalue.up = &mp->nvalue;
624 	fp->nofree  &= ~1;
625 	nv_disc(np,(Namfun_t*)fp, NV_FIRST);
626 	fp->nofree |= 1;
627 	nv_onattr(np,NV_ARRAY);
628 	mp->nvenv = (char*)np;
629 }
630 
631 /*
632  *        Increase the size of the indexed array of elements in <arp>
633  *        so that <maxi> is a legal index.  If <arp> is 0, an array
634  *        of the required size is allocated.  A pointer to the
635  *        allocated Namarr_t structure is returned.
636  *        <maxi> becomes the current index of the array.
637  */
638 static struct index_array *array_grow(Namval_t *np, register struct index_array *arp,int maxi)
639 {
640 	register struct index_array *ap;
641 	register int i;
642 	register int newsize = arsize(arp,maxi+1);
643 	if (maxi >= ARRAY_MAX)
644 		errormsg(SH_DICT,ERROR_exit(1),e_subscript, fmtbase((long)maxi,10,0));
645 	i = (newsize-1)*sizeof(union Value*)+newsize;
646 	ap = new_of(struct index_array,i);
647 	memset((void*)ap,0,sizeof(*ap)+i);
648 	ap->maxi = newsize;
649 	ap->cur = maxi;
650 	ap->bits =  (unsigned char*)&ap->val[newsize];
651 	memset(ap->bits, 0, newsize);
652 	if(arp)
653 	{
654 		ap->header = arp->header;
655 		ap->header.hdr.dsize = sizeof(*ap) + i;
656 		for(i=0;i < arp->maxi;i++)
657 			ap->val[i].cp = arp->val[i].cp;
658 		memcpy(ap->bits, arp->bits, arp->maxi);
659 		array_setptr(np,arp,ap);
660 		free((void*)arp);
661 	}
662 	else
663 	{
664 		Namval_t *mp=0;
665 		ap->header.hdr.dsize = sizeof(*ap) + i;
666 		i = 0;
667 		ap->header.fun = 0;
668 		if(nv_isnull(np) && nv_isattr(np,NV_NOFREE))
669 		{
670 			i = ARRAY_TREE;
671 			nv_offattr(np,NV_NOFREE);
672 		}
673 		if(np->nvalue.cp==Empty)
674 			np->nvalue.cp=0;
675 		if(nv_hasdisc(np,&array_disc) || nv_isvtree(np))
676 		{
677 			ap->header.table = dtopen(&_Nvdisc,Dtoset);
678 			mp = nv_search("0", ap->header.table,NV_ADD);
679 			if(mp && nv_isnull(mp))
680 			{
681 				Namfun_t *fp;
682 				ap->val[0].np = mp;
683 				array_setbit(ap->bits,0,ARRAY_CHILD);
684 				for(fp=np->nvfun; fp && !fp->disc->readf; fp=fp->next);
685 				if(fp && fp->disc && fp->disc->readf)
686 					(*fp->disc->readf)(mp,(Sfio_t*)0,0,fp);
687 				i++;
688 			}
689 		}
690 		else if((ap->val[0].cp=np->nvalue.cp))
691 			i++;
692 		else if(nv_isattr(np,NV_INTEGER) && !nv_isnull(np))
693 		{
694 			Sfdouble_t d= nv_getnum(np);
695 			i++;
696 		}
697 		ap->header.nelem = i;
698 		ap->header.hdr.disc = &array_disc;
699 		nv_disc(np,(Namfun_t*)ap, NV_FIRST);
700 		nv_onattr(np,NV_ARRAY);
701 		if(mp)
702 		{
703 			array_copytree(np,mp);
704 			ap->header.hdr.nofree &= ~1;
705 		}
706 	}
707 	for(;i < newsize;i++)
708 		ap->val[i].cp = 0;
709 	return(ap);
710 }
711 
712 int nv_atypeindex(Namval_t *np, const char *tname)
713 {
714 	Namval_t	*tp;
715 	int		offset = staktell();
716 	int		n = strlen(tname)-1;
717 	sfprintf(stkstd,"%s.%.*s%c",NV_CLASS,n,tname,0);
718 	tp = nv_open(stakptr(offset), sh.var_tree, NV_NOADD|NV_VARNAME);
719 	stakseek(offset);
720 	if(tp)
721 	{
722 		struct index_array *ap = (struct index_array*)nv_arrayptr(np);
723 		if(!nv_hasdisc(tp,&ENUM_disc))
724 			errormsg(SH_DICT,ERROR_exit(1),e_notenum,tp->nvname);
725 		if(!ap)
726 			ap = array_grow(np,ap,1);
727 		ap->xp = calloc(NV_MINSZ,1);
728 		np = nv_namptr(ap->xp,0);
729 		np->nvname = tp->nvname;
730 		nv_onattr(np,NV_MINIMAL);
731 		nv_clone(tp,np,NV_NOFREE);
732 		nv_offattr(np,NV_RDONLY);
733 		return(1);
734 	}
735 	errormsg(SH_DICT,ERROR_exit(1),e_unknowntype, n,tname);
736 	return(0);
737 }
738 
739 Namarr_t *nv_arrayptr(register Namval_t *np)
740 {
741 	if(nv_isattr(np,NV_ARRAY))
742 		return((Namarr_t*)nv_hasdisc(np, &array_disc));
743 	return(0);
744 }
745 
746 /*
747  * Verify that argument is an indexed array and convert to associative,
748  * freeing relevant storage
749  */
750 static Namarr_t *nv_changearray(Namval_t *np, void *(*fun)(Namval_t*,const char*,int))
751 {
752 	register Namarr_t *ap;
753 	char numbuff[NUMSIZE+1];
754 	unsigned dot, digit, n;
755 	union Value *up;
756 	struct index_array *save_ap;
757 	register char *string_index=&numbuff[NUMSIZE];
758 	numbuff[NUMSIZE]='\0';
759 
760 	if(!fun || !(ap = nv_arrayptr(np)) || is_associative(ap))
761 		return(NIL(Namarr_t*));
762 
763 	nv_stack(np,&ap->hdr);
764 	save_ap = (struct index_array*)nv_stack(np,0);
765 	ap = (Namarr_t*)((*fun)(np, NIL(char*), NV_AINIT));
766 	ap->nelem = 0;
767 	ap->fun = fun;
768 	nv_onattr(np,NV_ARRAY);
769 
770 	for(dot = 0; dot < (unsigned)save_ap->maxi; dot++)
771 	{
772 		if(save_ap->val[dot].cp)
773 		{
774 			if ((digit = dot)== 0)
775 				*--string_index = '0';
776 			else while( n = digit )
777 			{
778 				digit /= 10;
779 				*--string_index = '0' + (n-10*digit);
780 			}
781 			nv_putsub(np, string_index, ARRAY_ADD);
782 			up = (union Value*)((*ap->fun)(np,NIL(char*),0));
783 			up->cp = save_ap->val[dot].cp;
784 			save_ap->val[dot].cp = 0;
785 		}
786 		string_index = &numbuff[NUMSIZE];
787 	}
788 	free((void*)save_ap);
789 	return(ap);
790 }
791 
792 /*
793  * set the associative array processing method for node <np> to <fun>
794  * The array pointer is returned if sucessful.
795  */
796 Namarr_t *nv_setarray(Namval_t *np, void *(*fun)(Namval_t*,const char*,int))
797 {
798 	register Namarr_t *ap;
799 	char		*value=0;
800 	Namfun_t	*fp;
801 	int		nelem = 0;
802 	if(fun && (ap = nv_arrayptr(np)))
803 	{
804 		/*
805 		 * if it's already an indexed array, convert to
806 		 * associative structure
807 		 */
808 		if(!is_associative(ap))
809 			ap = nv_changearray(np, fun);
810 		return(ap);
811 	}
812 	if(nv_isnull(np) && nv_isattr(np,NV_NOFREE))
813 	{
814 		nelem = ARRAY_TREE;
815 		nv_offattr(np,NV_NOFREE);
816 	}
817 	if(!(fp=nv_isvtree(np)))
818 		value = nv_getval(np);
819 	if(fun && !ap && (ap = (Namarr_t*)((*fun)(np, NIL(char*), NV_AINIT))))
820 	{
821 		/* check for preexisting initialization and save */
822 		ap->nelem = nelem;
823 		ap->fun = fun;
824 		nv_onattr(np,NV_ARRAY);
825 		if(fp || value)
826 		{
827 			nv_putsub(np, "0", ARRAY_ADD);
828 			if(value)
829 				nv_putval(np, value, 0);
830 			else
831 			{
832 				Namval_t *mp = (Namval_t*)((*fun)(np,NIL(char*),NV_ACURRENT));
833 				array_copytree(np,mp);
834 			}
835 		}
836 		return(ap);
837 	}
838 	return(NIL(Namarr_t*));
839 }
840 
841 /*
842  * move parent subscript into child
843  */
844 Namval_t *nv_arraychild(Namval_t *np, Namval_t *nq, int c)
845 {
846 	Namfun_t		*fp;
847 	register Namarr_t	*ap = nv_arrayptr(np);
848 	union Value		*up;
849 	Namval_t		*tp;
850 	if(!nq)
851 		return(ap?array_find(np,ap, ARRAY_LOOKUP):0);
852 	if(!ap)
853 	{
854 		nv_putsub(np, NIL(char*), ARRAY_FILL);
855 		ap = nv_arrayptr(np);
856 	}
857 	if(!(up = array_getup(np,ap,0)))
858 		return((Namval_t*)0);
859 	np->nvalue.cp = up->cp;
860 	if((tp=nv_type(np)) || c)
861 	{
862 		ap->nelem |= ARRAY_NOCLONE;
863 		nq->nvenv = (char*)np;
864 		if(c=='t')
865 			nv_clone(tp,nq, 0);
866 		else
867 			nv_clone(np, nq, NV_NODISC);
868 		nv_offattr(nq,NV_ARRAY);
869 		ap->nelem &= ~ARRAY_NOCLONE;
870 	}
871 	nq->nvenv = (char*)np;
872 	if((fp=nq->nvfun) && fp->disc && fp->disc->setdisc && (fp = nv_disc(nq,fp,NV_POP)))
873 		free((void*)fp);
874 	if(!ap->fun)
875 	{
876 		struct index_array *aq = (struct index_array*)ap;
877 		array_setbit(aq->bits,aq->cur,ARRAY_CHILD);
878 		up->np = nq;
879 	}
880 	if(c=='.')
881 		nv_setvtree(nq);
882 	return(nq);
883 }
884 
885 /*
886  * This routine sets subscript of <np> to the next element, if any.
887  * The return value is zero, if there are no more elements
888  * Otherwise, 1 is returned.
889  */
890 int nv_nextsub(Namval_t *np)
891 {
892 	register struct index_array	*ap = (struct index_array*)nv_arrayptr(np);
893 	register unsigned		dot;
894 	struct index_array		*aq=0, *ar=0;
895 	if(!ap || !(ap->header.nelem&ARRAY_SCAN))
896 		return(0);
897 	if(is_associative(ap))
898 	{
899 		Namval_t	*nq;
900 		if(nq=(*ap->header.fun)(np,NIL(char*),NV_ANEXT))
901 		{
902 			if(nv_isattr(nq,NV_CHILD))
903 				nv_putsub(nq->nvalue.np,NIL(char*),ARRAY_UNDEF);
904 			return(1);
905 		}
906 		ap->header.nelem &= ~(ARRAY_SCAN|ARRAY_NOCHILD);
907 		return(0);
908 	}
909 	if(!(ap->header.nelem&ARRAY_NOSCOPE))
910 		ar = (struct index_array*)ap->header.scope;
911 	for(dot=ap->cur+1; dot <  (unsigned)ap->maxi; dot++)
912 	{
913 		aq = ap;
914 		if(!ap->val[dot].cp && !(ap->header.nelem&ARRAY_NOSCOPE))
915 		{
916 			if(!(aq=ar) || dot>=(unsigned)aq->maxi)
917 				continue;
918 		}
919 		if(aq->val[dot].cp)
920 		{
921 			ap->cur = dot;
922 			if(array_isbit(aq->bits, dot,ARRAY_CHILD))
923 			{
924 				Namval_t *mp = aq->val[dot].np;
925 				if((aq->header.nelem&ARRAY_NOCHILD) && nv_isvtree(mp))
926 					continue;
927 				nv_putsub(mp,NIL(char*),ARRAY_UNDEF);
928 			}
929 			return(1);
930 		}
931 	}
932 	ap->header.nelem &= ~(ARRAY_SCAN|ARRAY_NOCHILD);
933 	ap->cur = 0;
934 	return(0);
935 }
936 
937 /*
938  * Set an array subscript for node <np> given the subscript <sp>
939  * An array is created if necessary.
940  * <mode> can be a number, plus or more of symbolic constants
941  *    ARRAY_SCAN, ARRAY_UNDEF, ARRAY_ADD
942  * The node pointer is returned which can be NULL if <np> is
943  *    not already array and the ARRAY_ADD bit of <mode> is not set.
944  * ARRAY_FILL sets the specified subscript to the empty string when
945  *   ARRAY_ADD is specified and there is no value or sets all
946  * the elements up to the number specified if ARRAY_ADD is not specified
947  */
948 Namval_t *nv_putsub(Namval_t *np,register char *sp,register long mode)
949 {
950 	register struct index_array *ap = (struct index_array*)nv_arrayptr(np);
951 	register int size = (mode&ARRAY_MASK);
952 	if(!ap || !ap->header.fun)
953 	{
954 		if(sp)
955 		{
956 			if(ap && ap->xp && !strmatch(sp,"+([0-9])"))
957 			{
958 				Namval_t *mp = nv_namptr(ap->xp,0);
959 				nv_putval(mp, sp,0);
960 				size = nv_getnum(mp);
961 			}
962 			else
963 				size = (int)sh_arith((char*)sp);
964 		}
965 		if(size <0 && ap)
966 			size += array_maxindex(np);
967 		if(size >= ARRAY_MAX || (size < 0))
968 		{
969 			errormsg(SH_DICT,ERROR_exit(1),e_subscript, nv_name(np));
970 			return(NIL(Namval_t*));
971 		}
972 		if(!ap || size>=ap->maxi)
973 		{
974 			if(size==0 && !(mode&ARRAY_FILL))
975 				return(NIL(Namval_t*));
976 			if(sh.subshell)
977 				np = sh_assignok(np,1);
978 			ap = array_grow(np, ap,size);
979 		}
980 		ap->header.nelem &= ~ARRAY_UNDEF;
981 		ap->header.nelem |= (mode&(ARRAY_SCAN|ARRAY_NOCHILD|ARRAY_UNDEF|ARRAY_NOSCOPE));
982 #if 0
983 		if(array_isbit(ap->bits,oldsize,ARRAY_CHILD))
984 			mp = ap->val[oldsize].np;
985 		if(size != oldsize && mp->nvalue.cp)
986 		{
987 			Namfun_t *nfp;
988 			for(nfp=np->nvfun; nfp; nfp=nfp->next)
989 			{
990 				if(nfp->disc && nfp->disc->readf)
991 				{
992 					(*nfp->disc->readf)(mp,(Sfio_t*)0,0,nfp);
993 					break;
994 				}
995 			}
996 		}
997 #endif
998 		ap->cur = size;
999 		if((mode&ARRAY_SCAN) && (ap->cur--,!nv_nextsub(np)))
1000 			np = 0;
1001 		if(mode&(ARRAY_FILL|ARRAY_ADD))
1002 		{
1003 			if(!(mode&ARRAY_ADD))
1004 			{
1005 				int n;
1006 				for(n=0; n <= size; n++)
1007 				{
1008 					if(!ap->val[n].cp)
1009 					{
1010 						ap->val[n].cp = Empty;
1011 						if(!array_covered(np,ap))
1012 							ap->header.nelem++;
1013 					}
1014 				}
1015 				if(n=ap->maxi-ap->maxi)
1016 					memset(&ap->val[size],0,n*sizeof(union Value));
1017 			}
1018 			else if(!ap->val[size].cp)
1019 			{
1020 				if(sh.subshell)
1021 					np = sh_assignok(np,1);
1022 				ap->val[size].cp = Empty;
1023 				if(!array_covered(np,ap))
1024 					ap->header.nelem++;
1025 			}
1026 		}
1027 		else if(!(mode&ARRAY_SCAN))
1028 		{
1029 			ap->header.nelem &= ~ARRAY_SCAN;
1030 			if(array_isbit(ap->bits,size,ARRAY_CHILD))
1031 				nv_putsub(ap->val[size].np,NIL(char*),ARRAY_UNDEF);
1032 			if(sp && !(mode&ARRAY_ADD) && !ap->val[size].cp)
1033 				np = 0;
1034 		}
1035 		return((Namval_t*)np);
1036 	}
1037 	ap->header.nelem &= ~ARRAY_UNDEF;
1038 	if(!(mode&ARRAY_FILL))
1039 		ap->header.nelem &= ~ARRAY_SCAN;
1040 	ap->header.nelem |= (mode&(ARRAY_SCAN|ARRAY_NOCHILD|ARRAY_UNDEF|ARRAY_NOSCOPE));
1041 	if(sp)
1042 	{
1043 		if(mode&ARRAY_SETSUB)
1044 		{
1045 			(*ap->header.fun)(np, sp, NV_ASETSUB);
1046 			return(np);
1047 		}
1048 		(*ap->header.fun)(np, sp, (mode&ARRAY_ADD)?NV_AADD:0);
1049 		if(!(mode&(ARRAY_SCAN|ARRAY_ADD)) && !(*ap->header.fun)(np,NIL(char*),NV_ACURRENT))
1050 			np = 0;
1051 	}
1052 	else if(mode&ARRAY_SCAN)
1053 		(*ap->header.fun)(np,(char*)np,0);
1054 	else if(mode&ARRAY_UNDEF)
1055 		(*ap->header.fun)(np, "",0);
1056 	if((mode&ARRAY_SCAN) && !nv_nextsub(np))
1057 		np = 0;
1058 	return(np);
1059 }
1060 
1061 /*
1062  * process an array subscript for node <np> given the subscript <cp>
1063  * returns pointer to character after the subscript
1064  */
1065 char *nv_endsubscript(Namval_t *np, register char *cp, int mode)
1066 {
1067 	register int count=1, quoted=0, c;
1068 	register char *sp = cp+1;
1069 	/* first find matching ']' */
1070 	while(count>0 && (c= *++cp))
1071 	{
1072 		if(c=='\\' && (!(mode&NV_SUBQUOTE) || (c=cp[1])=='[' || c==']' || c=='\\' || c=='*' || c=='@'))
1073 		{
1074 			quoted=1;
1075 			cp++;
1076 		}
1077 		else if(c=='[')
1078 			count++;
1079 		else if(c==']')
1080 			count--;
1081 	}
1082 	*cp = 0;
1083 	if(quoted)
1084 	{
1085 		/* strip escape characters */
1086 		count = staktell();
1087 		stakwrite(sp,1+cp-sp);
1088 		sh_trim(sp=stakptr(count));
1089 	}
1090 	if(mode && np)
1091 	{
1092 		Namarr_t *ap = nv_arrayptr(np);
1093 		int scan = 0;
1094 		if(ap)
1095 			scan = ap->nelem&ARRAY_SCAN;
1096 		if((mode&NV_ASSIGN) && (cp[1]=='=' || cp[1]=='+'))
1097 			mode |= NV_ADD;
1098 		nv_putsub(np, sp, ((mode&NV_ADD)?ARRAY_ADD:0)|(cp[1]&&(mode&NV_ADD)?ARRAY_FILL:mode&ARRAY_FILL));
1099 		if(scan)
1100 			ap->nelem |= scan;
1101 	}
1102 	if(quoted)
1103 		stakseek(count);
1104 	*cp++ = c;
1105 	return(cp);
1106 }
1107 
1108 
1109 Namval_t *nv_opensub(Namval_t* np)
1110 {
1111 	register struct index_array *ap = (struct index_array*)nv_arrayptr(np);
1112 	if(ap)
1113 	{
1114 		if(is_associative(ap))
1115 			return((Namval_t*)((*ap->header.fun)(np,NIL(char*),NV_ACURRENT)));
1116 		else if(array_isbit(ap->bits,ap->cur,ARRAY_CHILD))
1117 			return(ap->val[ap->cur].np);
1118 	}
1119 	return(NIL(Namval_t*));
1120 }
1121 
1122 char	*nv_getsub(Namval_t* np)
1123 {
1124 	static char numbuff[NUMSIZE];
1125 	register struct index_array *ap;
1126 	register unsigned dot, n;
1127 	register char *cp = &numbuff[NUMSIZE];
1128 	if(!np || !(ap = (struct index_array*)nv_arrayptr(np)))
1129 		return(NIL(char*));
1130 	if(is_associative(ap))
1131 		return((char*)((*ap->header.fun)(np,NIL(char*),NV_ANAME)));
1132 	if(ap->xp)
1133 	{
1134 		np = nv_namptr(ap->xp,0);
1135 		np->nvalue.s = ap->cur;
1136 		return(nv_getval(np));
1137 	}
1138 	if((dot = ap->cur)==0)
1139 		*--cp = '0';
1140 	else while(n=dot)
1141 	{
1142 		dot /= 10;
1143 		*--cp = '0' + (n-10*dot);
1144 	}
1145 	return(cp);
1146 }
1147 
1148 /*
1149  * If <np> is an indexed array node, the current subscript index
1150  * returned, otherwise returns -1
1151  */
1152 int nv_aindex(register Namval_t* np)
1153 {
1154 	Namarr_t *ap = nv_arrayptr(np);
1155 	if(!ap)
1156 		return(0);
1157 	else if(is_associative(ap))
1158 		return(-1);
1159 	return(((struct index_array*)(ap))->cur&ARRAY_MASK);
1160 }
1161 
1162 int nv_arraynsub(register Namarr_t* ap)
1163 {
1164 	return(array_elem(ap));
1165 }
1166 
1167 int nv_aimax(register Namval_t* np)
1168 {
1169 	struct index_array *ap = (struct index_array*)nv_arrayptr(np);
1170 	int sub = -1;
1171 	if(!ap || is_associative(&ap->header))
1172 		return(-1);
1173 	sub = ap->maxi;
1174 	while(--sub>0 && ap->val[sub].cp==0);
1175 	return(sub);
1176 }
1177 
1178 /*
1179  *  This is the default implementation for associative arrays
1180  */
1181 void *nv_associative(register Namval_t *np,const char *sp,int mode)
1182 {
1183 	register struct assoc_array *ap = (struct assoc_array*)nv_arrayptr(np);
1184 	register int type;
1185 	switch(mode)
1186 	{
1187 	    case NV_AINIT:
1188 		if(ap = (struct assoc_array*)calloc(1,sizeof(struct assoc_array)))
1189 		{
1190 			ap->header.table = dtopen(&_Nvdisc,Dtoset);
1191 			ap->cur = 0;
1192 			ap->pos = 0;
1193 			ap->header.hdr.disc = &array_disc;
1194 			nv_disc(np,(Namfun_t*)ap, NV_FIRST);
1195 			ap->header.hdr.dsize = sizeof(struct assoc_array);
1196 			ap->header.hdr.nofree &= ~1;
1197 		}
1198 		return((void*)ap);
1199 	    case NV_ADELETE:
1200 		if(ap->cur)
1201 		{
1202 			if(!ap->header.scope || (Dt_t*)ap->header.scope==ap->header.table || !nv_search(ap->cur->nvname,(Dt_t*)ap->header.scope,0))
1203 				ap->header.nelem--;
1204 			_nv_unset(ap->cur,NV_RDONLY);
1205 			nv_delete(ap->cur,ap->header.table,0);
1206 			ap->cur = 0;
1207 		}
1208 		return((void*)ap);
1209 	    case NV_AFREE:
1210 		ap->pos = 0;
1211 		if(ap->header.scope)
1212 		{
1213 			ap->header.table = dtview(ap->header.table,(Dt_t*)0);
1214 			dtclose(ap->header.scope);
1215 			ap->header.scope = 0;
1216 		}
1217 		else
1218 			dtclose(ap->header.table);
1219 		return((void*)ap);
1220 	    case NV_ANEXT:
1221 		if(!ap->pos)
1222 		{
1223 			if((ap->header.nelem&ARRAY_NOSCOPE) && ap->header.scope && dtvnext(ap->header.table))
1224 			{
1225 				ap->header.scope = dtvnext(ap->header.table);
1226 				ap->header.table->view = 0;
1227 			}
1228 			if(!(ap->pos=ap->cur))
1229 				ap->pos = (Namval_t*)dtfirst(ap->header.table);
1230 		}
1231 		else
1232 			ap->pos = ap->nextpos;
1233 		for(;ap->cur=ap->pos; ap->pos=ap->nextpos)
1234 		{
1235 			ap->nextpos = (Namval_t*)dtnext(ap->header.table,ap->pos);
1236 			if(ap->cur->nvalue.cp)
1237 			{
1238 				if((ap->header.nelem&ARRAY_NOCHILD) && nv_isattr(ap->cur,NV_CHILD))
1239 					continue;
1240 				return((void*)ap);
1241 			}
1242 		}
1243 		if((ap->header.nelem&ARRAY_NOSCOPE) && ap->header.scope && !dtvnext(ap->header.table))
1244 		{
1245 			ap->header.table->view = (Dt_t*)ap->header.scope;
1246 			ap->header.scope = ap->header.table;
1247 		}
1248 		return(NIL(void*));
1249 	    case NV_ASETSUB:
1250 		ap->cur = (Namval_t*)sp;
1251 		return((void*)ap->cur);
1252 	    case NV_ACURRENT:
1253 		if(ap->cur)
1254 			ap->cur->nvenv = (char*)np;
1255 		return((void*)ap->cur);
1256 	    case NV_ANAME:
1257 		if(ap->cur)
1258 			return((void*)ap->cur->nvname);
1259 		return(NIL(void*));
1260 	    default:
1261 		if(sp)
1262 		{
1263 			Namval_t *mp=0;
1264 			ap->cur = 0;
1265 			if(sp==(char*)np)
1266 				return(0);
1267 			type = nv_isattr(np,NV_PUBLIC&~(NV_ARRAY|NV_CHILD|NV_MINIMAL));
1268 			if(mode)
1269 				mode = NV_ADD|HASH_NOSCOPE;
1270 			else if(ap->header.nelem&ARRAY_NOSCOPE)
1271 				mode = HASH_NOSCOPE;
1272 			if(*sp==0 && (mode&NV_ADD))
1273 				errormsg(SH_DICT,ERROR_warn(0),"adding empty subscript");
1274 			if(sh.subshell && (mp=nv_search(sp,ap->header.table,0)) && nv_isnull(mp))
1275 				ap->cur = mp;
1276 			if((mp || (mp=nv_search(sp,ap->header.table,mode))) && nv_isnull(mp) && (mode&NV_ADD))
1277 			{
1278 				nv_onattr(mp,type);
1279 				mp->nvenv = (char*)np;
1280 				if((mode&NV_ADD) && nv_type(np))
1281 					nv_arraychild(np,mp,0);
1282 				if(sh.subshell)
1283 					np = sh_assignok(np,1);
1284 				if(!ap->header.scope || !nv_search(sp,dtvnext(ap->header.table),0))
1285 					ap->header.nelem++;
1286 				if(nv_isnull(mp))
1287 				{
1288 					if(ap->header.nelem&ARRAY_TREE)
1289 						nv_setvtree(mp);
1290 					mp->nvalue.cp = Empty;
1291 				}
1292 			}
1293 			else if(ap->header.nelem&ARRAY_SCAN)
1294 			{
1295 				Namval_t fake;
1296 				fake.nvname = (char*)sp;
1297 				ap->pos = mp = (Namval_t*)dtprev(ap->header.table,&fake);
1298 				ap->nextpos = (Namval_t*)dtnext(ap->header.table,mp);
1299 			}
1300 			np = mp;
1301 			if(ap->pos && ap->pos==np)
1302 				ap->header.nelem |= ARRAY_SCAN;
1303 			else if(!(ap->header.nelem&ARRAY_SCAN))
1304 				ap->pos = 0;
1305 			ap->cur = np;
1306 		}
1307 		if(ap->cur)
1308 			return((void*)(&ap->cur->nvalue));
1309 		else
1310 			return((void*)(&ap->cur));
1311 	}
1312 }
1313 
1314 /*
1315  * Assign values to an array
1316  */
1317 void nv_setvec(register Namval_t *np,int append,register int argc,register char *argv[])
1318 {
1319 	int arg0=0;
1320 	struct index_array *ap=0,*aq;
1321 	if(nv_isarray(np))
1322 	{
1323 		ap = (struct index_array*)nv_arrayptr(np);
1324 		if(ap && is_associative(ap))
1325 			errormsg(SH_DICT,ERROR_exit(1),"cannot append index array to associative array %s",nv_name(np));
1326 	}
1327 	if(append)
1328 	{
1329 		if(ap)
1330 		{
1331 			if(!(aq = (struct index_array*)ap->header.scope))
1332 				aq = ap;
1333 			arg0 = ap->maxi;
1334 			while(--arg0>0 && ap->val[arg0].cp==0 && aq->val[arg0].cp==0);
1335 			arg0++;
1336 		}
1337 		else if(!nv_isnull(np))
1338 			arg0=1;
1339 	}
1340 	while(--argc >= 0)
1341 	{
1342 		nv_putsub(np,NIL(char*),(long)argc+arg0|ARRAY_FILL|ARRAY_ADD);
1343 		nv_putval(np,argv[argc],0);
1344 	}
1345 }
1346 
1347