xref: /titanic_41/usr/src/lib/libshell/common/sh/nvdisc.c (revision 68c47f65208790c466e5e484f2293d3baed71c6a)
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  * AT&T Labs
23  *
24  */
25 
26 #include        "defs.h"
27 #include        "variables.h"
28 #include        "builtins.h"
29 #include        "path.h"
30 
31 int nv_compare(Dt_t* dict, Void_t *sp, Void_t *dp, Dtdisc_t *disc)
32 {
33 	if(sp==dp)
34 		return(0);
35 	return(strcmp((char*)sp,(char*)dp));
36 }
37 
38 /*
39  * call the next getval function in the chain
40  */
41 char *nv_getv(Namval_t *np, register Namfun_t *nfp)
42 {
43 	register Namfun_t	*fp;
44 	register char *cp;
45 	if((fp = nfp) != NIL(Namfun_t*) && !nv_local)
46 		fp = nfp = nfp->next;
47 	nv_local=0;
48 	for(; fp; fp=fp->next)
49 	{
50 		if(!fp->disc || (!fp->disc->getnum && !fp->disc->getval))
51 			continue;
52 		if(!nv_isattr(np,NV_NODISC) || fp==(Namfun_t*)nv_arrayptr(np))
53 			break;
54 	}
55 	if(fp && fp->disc->getval)
56 		cp = (*fp->disc->getval)(np,fp);
57 	else if(fp && fp->disc->getnum)
58 	{
59 		sfprintf(sh.strbuf,"%.*Lg",12,(*fp->disc->getnum)(np,fp));
60 		cp = sfstruse(sh.strbuf);
61 	}
62 	else
63 	{
64 		nv_local=1;
65 		cp = nv_getval(np);
66 	}
67 	return(cp);
68 }
69 
70 /*
71  * call the next getnum function in the chain
72  */
73 Sfdouble_t nv_getn(Namval_t *np, register Namfun_t *nfp)
74 {
75 	register Namfun_t	*fp;
76 	register Sfdouble_t	d=0;
77 	char *str;
78 	if((fp = nfp) != NIL(Namfun_t*) && !nv_local)
79 		fp = nfp = nfp->next;
80 	nv_local=0;
81 	for(; fp; fp=fp->next)
82 	{
83 		if(!fp->disc || (!fp->disc->getnum && !fp->disc->getval))
84 			continue;
85 		if(!fp->disc->getnum && nv_isattr(np,NV_INTEGER))
86 			continue;
87 		if(!nv_isattr(np,NV_NODISC) || fp==(Namfun_t*)nv_arrayptr(np))
88 			break;
89 	}
90 	if(fp && fp->disc && fp->disc->getnum)
91 		d = (*fp->disc->getnum)(np,fp);
92 	else if(nv_isattr(np,NV_INTEGER))
93 	{
94 		nv_local = 1;
95 		d =  nv_getnum(np);
96 	}
97 	else
98 	{
99 		if(fp && fp->disc && fp->disc->getval)
100 			str = (*fp->disc->getval)(np,fp);
101 		else
102 			str = nv_getv(np,fp?fp:nfp);
103 		if(str && *str)
104 		{
105 			while(*str=='0')
106 				str++;
107 			d = sh_arith(str);
108 		}
109 	}
110 	return(d);
111 }
112 
113 /*
114  * call the next assign function in the chain
115  */
116 void nv_putv(Namval_t *np, const char *value, int flags, register Namfun_t *nfp)
117 {
118 	register Namfun_t	*fp, *fpnext;
119 	if((fp=nfp) != NIL(Namfun_t*) && !nv_local)
120 		fp = nfp = nfp->next;
121 	nv_local=0;
122 	if(flags&NV_NODISC)
123 		fp = 0;
124 	for(; fp; fp=fpnext)
125 	{
126 		fpnext = fp->next;
127 		if(!fp->disc || !fp->disc->putval)
128 		{
129 			if(!value)
130 			{
131 				if(fp->disc || !(fp->nofree&1))
132 					nv_disc(np,fp,NV_POP);
133 				if(!(fp->nofree&1))
134 					free((void*)fp);
135 			}
136 			continue;
137 		}
138 		if(!nv_isattr(np,NV_NODISC) || fp==(Namfun_t*)nv_arrayptr(np))
139 			break;
140 	}
141 	if(fp && fp->disc->putval)
142 		(*fp->disc->putval)(np,value, flags, fp);
143 	else
144 	{
145 		nv_local=1;
146 		if(value)
147 			nv_putval(np, value, flags);
148 		else
149 			_nv_unset(np, flags&(NV_RDONLY|NV_EXPORT));
150 	}
151 }
152 
153 #define	LOOKUPS		0
154 #define	ASSIGN		1
155 #define	APPEND		2
156 #define	UNASSIGN	3
157 #define	LOOKUPN		4
158 #define BLOCKED		((Namval_t*)&nv_local)
159 
160 struct	vardisc
161 {
162 	Namfun_t	fun;
163 	Namval_t	*disc[5];
164 };
165 
166 struct blocked
167 {
168 	struct blocked	*next;
169 	Namval_t	*np;
170 	int		flags;
171 	void		*sub;
172 	int		isub;
173 };
174 
175 static struct blocked	*blist;
176 
177 #define isblocked(bp,type)	((bp)->flags & (1<<(type)))
178 #define block(bp,type)		((bp)->flags |= (1<<(type)))
179 #define unblock(bp,type)	((bp)->flags &= ~(1<<(type)))
180 
181 /*
182  * returns pointer to blocking structure
183  */
184 static struct blocked *block_info(Namval_t *np, struct blocked *pp)
185 {
186 	register struct blocked	*bp;
187 	void			*sub=0;
188 	int			isub=0;
189 	if(nv_isarray(np) && (isub=nv_aindex(np)) < 0)
190 		sub = nv_associative(np,(const char*)0,NV_ACURRENT);
191 	for(bp=blist ; bp; bp=bp->next)
192 	{
193 		if(bp->np==np && bp->sub==sub && bp->isub==isub)
194 			return(bp);
195 	}
196 	if(pp)
197 	{
198 		pp->np = np;
199 		pp->flags = 0;
200 		pp->isub = isub;
201 		pp->sub = sub;
202 		pp->next = blist;
203 		blist = pp;
204 	}
205 	return(pp);
206 }
207 
208 static void block_done(struct blocked *bp)
209 {
210 	blist = bp = bp->next;
211 	if(bp && (bp->isub>=0 || bp->sub))
212 		nv_putsub(bp->np, bp->sub,(bp->isub<0?0:bp->isub)|ARRAY_SETSUB);
213 }
214 
215 /*
216  * free discipline if no more discipline functions
217  */
218 static void chktfree(register Namval_t *np, register struct vardisc *vp)
219 {
220 	register int n;
221 	for(n=0; n< sizeof(vp->disc)/sizeof(*vp->disc); n++)
222 	{
223 		if(vp->disc[n])
224 			break;
225 	}
226 	if(n>=sizeof(vp->disc)/sizeof(*vp->disc))
227 	{
228 		/* no disc left so pop */
229 		Namfun_t *fp;
230 		if((fp=nv_stack(np, NIL(Namfun_t*))) && !(fp->nofree&1))
231 			free((void*)fp);
232 	}
233 }
234 
235 /*
236  * This function performs an assignment disc on the given node <np>
237  */
238 static void	assign(Namval_t *np,const char* val,int flags,Namfun_t *handle)
239 {
240 	int		type = (flags&NV_APPEND)?APPEND:ASSIGN;
241 	register	struct vardisc *vp = (struct vardisc*)handle;
242 	register	Namval_t *nq =  vp->disc[type];
243 	struct blocked	block, *bp = block_info(np, &block);
244 	Namval_t	node;
245 	union Value	*up = np->nvalue.up;
246 #if SHOPT_TYPEDEF
247 	Namval_t	*tp, *nr;
248 	if(val && (tp=nv_type(np)) && (nr=nv_open(val,sh.var_tree,NV_VARNAME|NV_ARRAY|NV_NOADD|NV_NOFAIL)) && tp==nv_type(nr))
249 	{
250 		char *sub = nv_getsub(np);
251 		nv_unset(np);
252 		if(sub)
253 		{
254 			nv_putsub(np, sub, ARRAY_ADD);
255 			nv_putval(np,nv_getval(nr), 0);
256 		}
257 		else
258 			nv_clone(nr,np,0);
259 		goto done;
260 	}
261 #endif /* SHOPT_TYPEDEF */
262 	if(val || isblocked(bp,type))
263 	{
264 		if(!nq || isblocked(bp,type))
265 		{
266 			nv_putv(np,val,flags,handle);
267 			goto done;
268 		}
269 		node = *SH_VALNOD;
270 		if(!nv_isnull(SH_VALNOD))
271 		{
272 			nv_onattr(SH_VALNOD,NV_NOFREE);
273 			nv_unset(SH_VALNOD);
274 		}
275 		if(flags&NV_INTEGER)
276 			nv_onattr(SH_VALNOD,(flags&(NV_LONG|NV_DOUBLE|NV_EXPNOTE|NV_HEXFLOAT|NV_SHORT)));
277 		nv_putval(SH_VALNOD, val, (flags&NV_INTEGER)?flags:NV_NOFREE);
278 	}
279 	else
280 		nq =  vp->disc[type=UNASSIGN];
281 	if(nq && !isblocked(bp,type))
282 	{
283 		int bflag;
284 		block(bp,type);
285 		if (type==APPEND && (bflag= !isblocked(bp,LOOKUPS)))
286 			block(bp,LOOKUPS);
287 		sh_fun(nq,np,(char**)0);
288 		unblock(bp,type);
289 		if(bflag)
290 			unblock(bp,LOOKUPS);
291 		if(!vp->disc[type])
292 			chktfree(np,vp);
293 	}
294 	if(nv_isarray(np))
295 		np->nvalue.up = up;
296 	if(val)
297 	{
298 		register char *cp;
299 		Sfdouble_t d;
300 		if(nv_isnull(SH_VALNOD))
301 			cp=0;
302 		else if(flags&NV_INTEGER)
303 		{
304 			d = nv_getnum(SH_VALNOD);
305 			cp = (char*)(&d);
306 			flags |= (NV_LONG|NV_DOUBLE);
307 			flags &= ~NV_SHORT;
308 		}
309 		else
310 			cp = nv_getval(SH_VALNOD);
311 		if(cp)
312 			nv_putv(np,cp,flags|NV_RDONLY,handle);
313 		nv_unset(SH_VALNOD);
314 		/* restore everything but the nvlink field */
315 		memcpy(&SH_VALNOD->nvname,  &node.nvname, sizeof(node)-sizeof(node.nvlink));
316 	}
317 	else if(sh_isstate(SH_INIT))
318 	{
319 		/* don't free functions during reinitialization */
320 		nv_putv(np,val,flags,handle);
321 	}
322 	else if(!nq || !isblocked(bp,type))
323 	{
324 		Dt_t *root = sh_subfuntree(1);
325 		int n;
326 		Namarr_t *ap;
327 		block(bp,type);
328 		nv_putv(np, val, flags, handle);
329 		if(sh.subshell)
330 			goto done;
331 		if(nv_isarray(np) && (ap=nv_arrayptr(np)) && ap->nelem>0)
332 			goto done;
333 		for(n=0; n < sizeof(vp->disc)/sizeof(*vp->disc); n++)
334 		{
335 			if((nq=vp->disc[n]) && !nv_isattr(nq,NV_NOFREE))
336 			{
337 				nv_unset(nq);
338 				dtdelete(root,nq);
339 			}
340 		}
341 		unblock(bp,type);
342 		nv_disc(np,handle,NV_POP);
343 		if(!(handle->nofree&1))
344 			free(handle);
345 	}
346 done:
347 	if(bp== &block)
348 		block_done(bp);
349 }
350 
351 /*
352  * This function executes a lookup disc and then performs
353  * the lookup on the given node <np>
354  */
355 static char*	lookup(Namval_t *np, int type, Sfdouble_t *dp,Namfun_t *handle)
356 {
357 	register struct vardisc	*vp = (struct vardisc*)handle;
358 	struct blocked		block, *bp = block_info(np, &block);
359 	register Namval_t	*nq = vp->disc[type];
360 	register char		*cp=0;
361 	Namval_t		node;
362 	union Value		*up = np->nvalue.up;
363 	if(nq && !isblocked(bp,type))
364 	{
365 		node = *SH_VALNOD;
366 		if(!nv_isnull(SH_VALNOD))
367 		{
368 			nv_onattr(SH_VALNOD,NV_NOFREE);
369 			nv_unset(SH_VALNOD);
370 		}
371 		if(type==LOOKUPN)
372 		{
373 			nv_onattr(SH_VALNOD,NV_DOUBLE|NV_INTEGER);
374 			nv_setsize(SH_VALNOD,10);
375 		}
376 		block(bp,type);
377 		sh_fun(nq,np,(char**)0);
378 		unblock(bp,type);
379 		if(!vp->disc[type])
380 			chktfree(np,vp);
381 		if(type==LOOKUPN)
382 		{
383 			cp = (char*)(SH_VALNOD->nvalue.cp);
384 			*dp = nv_getnum(SH_VALNOD);
385 		}
386 		else if(cp = nv_getval(SH_VALNOD))
387 			cp = stkcopy(stkstd,cp);
388 		_nv_unset(SH_VALNOD,NV_RDONLY);
389 		if(!nv_isnull(&node))
390 		{
391 			/* restore everything but the nvlink field */
392 			memcpy(&SH_VALNOD->nvname,  &node.nvname, sizeof(node)-sizeof(node.nvlink));
393 		}
394 	}
395 	if(nv_isarray(np))
396 		np->nvalue.up = up;
397 	if(!cp)
398 	{
399 		if(type==LOOKUPS)
400 			cp = nv_getv(np,handle);
401 		else
402 			*dp = nv_getn(np,handle);
403 	}
404 	if(bp== &block)
405 		block_done(bp);
406 	return(cp);
407 }
408 
409 static char*	lookups(Namval_t *np, Namfun_t *handle)
410 {
411 	return(lookup(np,LOOKUPS,(Sfdouble_t*)0,handle));
412 }
413 
414 static Sfdouble_t lookupn(Namval_t *np, Namfun_t *handle)
415 {
416 	Sfdouble_t	d;
417 	lookup(np,LOOKUPN, &d ,handle);
418 	return(d);
419 }
420 
421 
422 /*
423  * Set disc on given <event> to <action>
424  * If action==np, the current disc is returned
425  * A null return value indicates that no <event> is known for <np>
426  * If <event> is NULL, then return the event name after <action>
427  * If <event> is NULL, and <action> is NULL, return the first event
428  */
429 char *nv_setdisc(register Namval_t* np,register const char *event,Namval_t *action,register Namfun_t *fp)
430 {
431 	register struct vardisc *vp = (struct vardisc*)np->nvfun;
432 	register int type;
433 	char *empty = "";
434 	if(vp && !vp->fun.disc)
435 		vp = 0;
436 	if(np == (Namval_t*)fp)
437 	{
438 		register const char *name;
439 		register int getname=0;
440 		/* top level call, check for get/set */
441 		if(!event)
442 		{
443 			if(!action)
444 				return((char*)nv_discnames[0]);
445 			getname=1;
446 			event = (char*)action;
447 		}
448 		for(type=0; name=nv_discnames[type]; type++)
449 		{
450 			if(strcmp(event,name)==0)
451 				break;
452 		}
453 		if(getname)
454 		{
455 			event = 0;
456 			if(name && !(name = nv_discnames[++type]))
457 				action = 0;
458 		}
459 		if(!name)
460 		{
461 			for(fp=(Namfun_t*)vp; fp; fp=fp->next)
462 			{
463 				if(fp->disc && fp->disc->setdisc)
464 					return((*fp->disc->setdisc)(np,event,action,fp));
465 			}
466 		}
467 		else if(getname)
468 			return((char*)name);
469 	}
470 	if(!fp)
471 		return(NIL(char*));
472 	if(np != (Namval_t*)fp)
473 	{
474 		/* not the top level */
475 		while(fp = fp->next)
476 		{
477 			if(fp->disc && fp->disc->setdisc)
478 				return((*fp->disc->setdisc)(np,event,action,fp));
479 		}
480 		return(NIL(char*));
481 	}
482 	/* Handle GET/SET/APPEND/UNSET disc */
483 	if(vp && vp->fun.disc->putval!=assign)
484 		vp = 0;
485 	if(!vp)
486 	{
487 		Namdisc_t	*dp;
488 		if(action==np)
489 			return((char*)action);
490 		if(!(vp = newof(NIL(struct vardisc*),struct vardisc,1,sizeof(Namdisc_t))))
491 			return(0);
492 		dp = (Namdisc_t*)(vp+1);
493 		vp->fun.disc = dp;
494 		memset(dp,0,sizeof(*dp));
495 		dp->dsize = sizeof(struct vardisc);
496 		dp->putval = assign;
497 		nv_stack(np, (Namfun_t*)vp);
498 	}
499 	if(action==np)
500 	{
501 		action = vp->disc[type];
502 		empty = 0;
503 	}
504 	else if(action)
505 	{
506 		Namdisc_t *dp = (Namdisc_t*)vp->fun.disc;
507 		if(type==LOOKUPS)
508 			dp->getval = lookups;
509 		else if(type==LOOKUPN)
510 			dp->getnum = lookupn;
511 		vp->disc[type] = action;
512 	}
513 	else
514 	{
515 		struct blocked *bp;
516 		action = vp->disc[type];
517 		vp->disc[type] = 0;
518 		if(!(bp=block_info(np,(struct blocked*)0)) || !isblocked(bp,UNASSIGN))
519 			chktfree(np,vp);
520 	}
521 	return(action?(char*)action:empty);
522 }
523 
524 /*
525  * Set disc on given <event> to <action>
526  * If action==np, the current disc is returned
527  * A null return value indicates that no <event> is known for <np>
528  * If <event> is NULL, then return the event name after <action>
529  * If <event> is NULL, and <action> is NULL, return the first event
530  */
531 static char *setdisc(register Namval_t* np,register const char *event,Namval_t *action,register Namfun_t *fp)
532 {
533 	register Nambfun_t *vp = (Nambfun_t*)fp;
534 	register int type,getname=0;
535 	register const char *name;
536 	const char **discnames = vp->bnames;
537 	/* top level call, check for discipline match */
538 	if(!event)
539 	{
540 		if(!action)
541 			return((char*)discnames[0]);
542 		getname=1;
543 		event = (char*)action;
544 	}
545 	for(type=0; name=discnames[type]; type++)
546 	{
547 		if(strcmp(event,name)==0)
548 			break;
549 	}
550 	if(getname)
551 	{
552 		event = 0;
553 		if(name && !(name = discnames[++type]))
554 			action = 0;
555 	}
556 	if(!name)
557 		return(nv_setdisc(np,event,action,fp));
558 	else if(getname)
559 		return((char*)name);
560 	/* Handle the disciplines */
561 	if(action==np)
562 		action = vp->bltins[type];
563 	else if(action)
564 		vp->bltins[type] = action;
565 	else
566 	{
567 		action = vp->bltins[type];
568 		vp->bltins[type] = 0;
569 	}
570 	return(action?(char*)action:"");
571 }
572 
573 static void putdisc(Namval_t* np, const char* val, int flag, Namfun_t* fp)
574 {
575 	nv_putv(np,val,flag,fp);
576 	if(!val && !(flag&NV_NOFREE))
577 	{
578 		register Nambfun_t *vp = (Nambfun_t*)fp;
579 		register int i;
580 		for(i=0; vp->bnames[i]; i++)
581 		{
582 			register Namval_t *mp;
583 			if((mp=vp->bltins[i]) && !nv_isattr(mp,NV_NOFREE))
584 			{
585 				if(is_abuiltin(mp))
586 				{
587 					if(mp->nvfun && !nv_isattr(mp,NV_NOFREE))
588 						free((void*)mp->nvfun);
589 					dtdelete(sh.bltin_tree,mp);
590 					free((void*)mp);
591 				}
592 			}
593 		}
594 		nv_disc(np,fp,NV_POP);
595 		if(!(fp->nofree&1))
596 			free((void*)fp);
597 
598 	}
599 }
600 
601 static const Namdisc_t Nv_bdisc	= {   0, putdisc, 0, 0, setdisc };
602 
603 Namfun_t *nv_clone_disc(register Namfun_t *fp, int flags)
604 {
605 	register Namfun_t	*nfp;
606 	register int		size;
607 	if(!fp->disc && !fp->next && (fp->nofree&1))
608 		return(fp);
609 	if(!(size=fp->dsize) && (!fp->disc || !(size=fp->disc->dsize)))
610 		size = sizeof(Namfun_t);
611 	if(!(nfp=newof(NIL(Namfun_t*),Namfun_t,1,size-sizeof(Namfun_t))))
612 		return(0);
613 	memcpy(nfp,fp,size);
614 	nfp->nofree &= ~1;
615 	nfp->nofree |= (flags&NV_RDONLY)?1:0;
616 	return(nfp);
617 }
618 
619 int nv_adddisc(Namval_t *np, const char **names, Namval_t **funs)
620 {
621 	register Nambfun_t *vp;
622 	register int n=0;
623 	register const char **av=names;
624 	if(av)
625 	{
626 		while(*av++)
627 			n++;
628 	}
629 	if(!(vp = newof(NIL(Nambfun_t*),Nambfun_t,1,n*sizeof(Namval_t*))))
630 		return(0);
631 	vp->fun.dsize = sizeof(Nambfun_t)+n*sizeof(Namval_t*);
632 	vp->fun.nofree |= 2;
633 	vp->num = n;
634 	if(funs)
635 		memcpy((void*)vp->bltins, (void*)funs,n*sizeof(Namval_t*));
636 	else while(n>=0)
637 		vp->bltins[n--] = 0;
638 	vp->fun.disc = &Nv_bdisc;
639 	vp->bnames = names;
640 	nv_stack(np,&vp->fun);
641 	return(1);
642 }
643 
644 /*
645  * push, pop, clne, or reorder disciplines onto node <np>
646  * mode can be one of
647  *    NV_FIRST:  Move or push <fp> to top of the stack or delete top
648  *    NV_LAST:	 Move or push <fp> to bottom of stack or delete last
649  *    NV_POP:	 Delete <fp> from top of the stack
650  *    NV_CLONE:  Replace fp with a copy created my malloc() and return it
651  */
652 Namfun_t *nv_disc(register Namval_t *np, register Namfun_t* fp, int mode)
653 {
654 	Namfun_t *lp, **lpp;
655 	if(nv_isref(np))
656 		return(0);
657 	if(mode==NV_CLONE && !fp)
658 		return(0);
659 	if(fp)
660 	{
661 		fp->subshell = sh.subshell;
662 		if((lp=np->nvfun)==fp)
663 		{
664 			if(mode==NV_CLONE)
665 			{
666 				lp = nv_clone_disc(fp,0);
667 				return(np->nvfun=lp);
668 			}
669 			if(mode==NV_FIRST || mode==0)
670 				return(fp);
671 			np->nvfun = lp->next;
672 			if(mode==NV_POP)
673 				return(fp);
674 			if(mode==NV_LAST && (lp->next==0 || lp->next->disc==0))
675 				return(fp);
676 		}
677 		/* see if <fp> is on the list already */
678 		lpp = &np->nvfun;
679 		if(lp)
680 		{
681 			while(lp->next && lp->next->disc)
682 			{
683 				if(lp->next==fp)
684 				{
685 					if(mode==NV_LAST && fp->next==0)
686 						return(fp);
687 					if(mode==NV_CLONE)
688 					{
689 						fp = nv_clone_disc(fp,0);
690 						lp->next = fp;
691 						return(fp);
692 					}
693 					lp->next = fp->next;
694 					if(mode==NV_POP)
695 						return(fp);
696 					if(mode!=NV_LAST)
697 						break;
698 				}
699 				lp = lp->next;
700 			}
701 			if(mode==NV_LAST)
702 				lpp = &lp->next;
703 		}
704 		if(mode==NV_POP)
705 			return(0);
706 		/* push */
707 		nv_offattr(np,NV_NODISC);
708 		if(mode==NV_LAST)
709 			fp->next = 0;
710 		else
711 		{
712 			if((fp->nofree&1) && *lpp)
713 				fp = nv_clone_disc(fp,0);
714 			fp->next = *lpp;
715 		}
716 		*lpp = fp;
717 	}
718 	else
719 	{
720 		if(mode==NV_FIRST)
721 			return(np->nvfun);
722 		else if(mode==NV_LAST)
723 			for(lp=np->nvfun; lp; fp=lp,lp=lp->next);
724 		else if(fp = np->nvfun)
725 			np->nvfun = fp->next;
726 	}
727 	return(fp);
728 }
729 
730 /*
731  * returns discipline pointer if discipline with specified functions
732  * is on the discipline stack
733  */
734 Namfun_t *nv_hasdisc(Namval_t *np, const Namdisc_t *dp)
735 {
736 	register Namfun_t *fp;
737 	for(fp=np->nvfun; fp; fp = fp->next)
738 	{
739 		if(fp->disc== dp)
740 			return(fp);
741 	}
742 	return(0);
743 }
744 
745 struct notify
746 {
747 	Namfun_t	hdr;
748 	char		**ptr;
749 };
750 
751 static void put_notify(Namval_t* np,const char *val,int flags,Namfun_t *fp)
752 {
753 	struct notify *pp = (struct notify*)fp;
754 	nv_putv(np,val,flags,fp);
755 	nv_stack(np,fp);
756 	nv_stack(np,(Namfun_t*)0);
757 	*pp->ptr = 0;
758 	if(!(fp->nofree&1))
759 		free((void*)fp);
760 }
761 
762 static const Namdisc_t notify_disc  = {  0, put_notify };
763 
764 int nv_unsetnotify(Namval_t *np, char **addr)
765 {
766 	register Namfun_t *fp;
767 	for(fp=np->nvfun;fp;fp=fp->next)
768 	{
769 		if(fp->disc->putval==put_notify && ((struct notify*)fp)->ptr==addr)
770 		{
771 			nv_stack(np,fp);
772 			nv_stack(np,(Namfun_t*)0);
773 			if(!(fp->nofree&1))
774 				free((void*)fp);
775 			return(1);
776 		}
777 	}
778 	return(0);
779 }
780 
781 int nv_setnotify(Namval_t *np, char **addr)
782 {
783 	struct notify *pp = newof(0,struct notify, 1,0);
784 	if(!pp)
785 		return(0);
786 	pp->ptr = addr;
787 	pp->hdr.disc = &notify_disc;
788 	nv_stack(np,&pp->hdr);
789 	return(1);
790 }
791 
792 static void *newnode(const char *name)
793 {
794 	register int s;
795 	register Namval_t *np = newof(0,Namval_t,1,s=strlen(name)+1);
796 	if(np)
797 	{
798 		np->nvname = (char*)np+sizeof(Namval_t);
799 		memcpy(np->nvname,name,s);
800 	}
801 	return((void*)np);
802 }
803 
804 #if SHOPT_NAMESPACE
805 /*
806  * clone a numeric value
807  */
808 static void *num_clone(register Namval_t *np, void *val)
809 {
810 	register int size;
811 	void *nval;
812 	if(!val)
813 		return(0);
814 	if(nv_isattr(np,NV_DOUBLE)==NV_DOUBLE)
815 	{
816 		if(nv_isattr(np,NV_LONG))
817 			size = sizeof(Sfdouble_t);
818 		else if(nv_isattr(np,NV_SHORT))
819 			size = sizeof(float);
820 		else
821 			size = sizeof(double);
822 	}
823 	else
824 	{
825 		if(nv_isattr(np,NV_LONG))
826 			size = sizeof(Sflong_t);
827 		else if(nv_isattr(np,NV_SHORT))
828 		{
829 			if(nv_isattr(np,NV_INT16P)==NV_INT16P)
830 				size = sizeof(short);
831 			else
832 				return((void*)np->nvalue.ip);
833 		}
834 		else
835 			size = sizeof(int32_t);
836 	}
837 	if(!(nval = malloc(size)))
838 		return(0);
839 	memcpy(nval,val,size);
840 	return(nval);
841 }
842 
843 void clone_all_disc( Namval_t *np, Namval_t *mp, int flags)
844 {
845 	register Namfun_t *fp, **mfp = &mp->nvfun, *nfp, *fpnext;
846 	for(fp=np->nvfun; fp;fp=fpnext)
847 	{
848 		fpnext = fp->next;
849 		if(!fpnext && (flags&NV_COMVAR) && fp->disc && fp->disc->namef)
850 			return;
851 		if((fp->nofree&2) && (flags&NV_NODISC))
852 			nfp = 0;
853 		if(fp->disc && fp->disc->clonef)
854 			nfp = (*fp->disc->clonef)(np,mp,flags,fp);
855 		else	if(flags&NV_MOVE)
856 			nfp = fp;
857 		else
858 			nfp = nv_clone_disc(fp,flags);
859 		if(!nfp)
860 			continue;
861 		nfp->next = 0;
862 		*mfp = nfp;
863 		mfp = &nfp->next;
864 	}
865 }
866 
867 /*
868  * clone <mp> from <np> flags can be one of the following
869  * NV_APPEND - append <np> onto <mp>
870  * NV_MOVE - move <np> to <mp>
871  * NV_NOFREE - mark the new node as nofree
872  * NV_NODISC - discplines with funs non-zero will not be copied
873  * NV_COMVAR - cloning a compound variable
874  */
875 int nv_clone(Namval_t *np, Namval_t *mp, int flags)
876 {
877 	Namfun_t	*fp, *fpnext;
878 	const char	*val = mp->nvalue.cp;
879 	unsigned short	flag = mp->nvflag;
880 	unsigned short	size = mp->nvsize;
881 	for(fp=mp->nvfun; fp; fp=fpnext)
882 	{
883 		fpnext = fp->next;
884 		if(!fpnext && (flags&NV_COMVAR) && fp->disc && fp->disc->namef)
885 			break;
886 		if(!(fp->nofree&1))
887 			free((void*)fp);
888 	}
889 	mp->nvfun = fp;
890 	if(fp=np->nvfun)
891 	{
892 		if(nv_isattr(mp,NV_EXPORT|NV_MINIMAL) == (NV_EXPORT|NV_MINIMAL))
893 		{
894 			mp->nvenv = 0;
895 			nv_offattr(mp,NV_MINIMAL);
896 		}
897 		if(!(flags&NV_COMVAR) && !nv_isattr(np,NV_MINIMAL) && np->nvenv && !(nv_isattr(mp,NV_MINIMAL)))
898 			mp->nvenv = np->nvenv;
899 		mp->nvflag &= NV_MINIMAL;
900 	        mp->nvflag |= np->nvflag&~(NV_ARRAY|NV_MINIMAL|NV_NOFREE);
901 		flag = mp->nvflag;
902 		clone_all_disc(np, mp, flags);
903 	}
904 	if(flags&NV_APPEND)
905 		return(1);
906 	if(mp->nvsize == size)
907 	        nv_setsize(mp,nv_size(np));
908 	if(mp->nvflag == flag)
909 	        mp->nvflag = (np->nvflag&~(NV_MINIMAL))|(mp->nvflag&NV_MINIMAL);
910 	if(mp->nvalue.cp==val && !nv_isattr(np,NV_INTEGER))
911 	{
912 		if(np->nvalue.cp && np->nvalue.cp!=Empty && (flags&NV_COMVAR) && !(flags&NV_MOVE))
913 		{
914 			if(size)
915 				mp->nvalue.cp = (char*)memdup(np->nvalue.cp,size);
916 			else
917 			        mp->nvalue.cp = strdup(np->nvalue.cp);
918 			nv_offattr(mp,NV_NOFREE);
919 		}
920 		else if(!(mp->nvalue.cp = np->nvalue.cp))
921 			nv_offattr(mp,NV_NOFREE);
922 	}
923 	if(flags&NV_MOVE)
924 	{
925 		if(nv_isattr(np,NV_INTEGER))
926 			mp->nvalue.ip = np->nvalue.ip;
927 		np->nvfun = 0;
928 		np->nvalue.cp = 0;
929 		if(!nv_isattr(np,NV_MINIMAL) || nv_isattr(mp,NV_EXPORT))
930 		        np->nvenv = 0;
931 		np->nvflag &= NV_MINIMAL;
932 	        nv_setsize(np,0);
933 		return(1);
934 	}
935 	if(nv_isattr(np,NV_INTEGER) && mp->nvalue.ip!=np->nvalue.ip)
936 	{
937 		mp->nvalue.ip = (int*)num_clone(np,(void*)np->nvalue.ip);
938 		nv_offattr(mp,NV_NOFREE);
939 	}
940 	else if(flags&NV_NOFREE)
941 	        nv_onattr(np,NV_NOFREE);
942 	return(1);
943 }
944 
945 /*
946  *  The following discipline is for copy-on-write semantics
947  */
948 static char* clone_getv(Namval_t *np, Namfun_t *handle)
949 {
950 	return(np->nvalue.np?nv_getval(np->nvalue.np):0);
951 }
952 
953 static Sfdouble_t clone_getn(Namval_t *np, Namfun_t *handle)
954 {
955 	return(np->nvalue.np?nv_getnum(np->nvalue.np):0);
956 }
957 
958 static void clone_putv(Namval_t *np,const char* val,int flags,Namfun_t *handle)
959 {
960 	Namfun_t *dp = nv_stack(np,(Namfun_t*)0);
961 	Namval_t *mp = np->nvalue.np;
962 	if(!sh.subshell)
963 		free((void*)dp);
964 	if(val)
965 		nv_clone(mp,np,NV_NOFREE);
966 	np->nvalue.cp = 0;
967 	nv_putval(np,val,flags);
968 }
969 
970 static const Namdisc_t clone_disc =
971 {
972 	0,
973 	clone_putv,
974 	clone_getv,
975 	clone_getn
976 };
977 
978 Namval_t *nv_mkclone(Namval_t *mp)
979 {
980 	Namval_t *np;
981 	Namfun_t *dp;
982 	np = newof(0,Namval_t,1,0);
983 	np->nvflag = mp->nvflag;
984 	np->nvsize = mp->nvsize;
985 	np->nvname = mp->nvname;
986 	np->nvalue.np = mp;
987 	np->nvflag = mp->nvflag;
988 	dp = newof(0,Namfun_t,1,0);
989 	dp->disc = &clone_disc;
990 	nv_stack(np,dp);
991 	dtinsert(nv_dict(sh.namespace),np);
992 	return(np);
993 }
994 #endif /* SHOPT_NAMESPACE */
995 
996 Namval_t *nv_search(const char *name, Dt_t *root, int mode)
997 {
998 	register Namval_t *np;
999 	register Dt_t *dp = 0;
1000 	if(mode&HASH_NOSCOPE)
1001 		dp = dtview(root,0);
1002 	if(mode&HASH_BUCKET)
1003 	{
1004 		Namval_t *mp = (void*)name;
1005 		if(!(np = dtsearch(root,mp)) && (mode&NV_ADD))
1006 			name = nv_name(mp);
1007 	}
1008 	else
1009 	{
1010 		if(*name=='.' && root==sh.var_tree && !dp)
1011 			root = sh.var_base;
1012 		np = dtmatch(root,(void*)name);
1013 	}
1014 	if(!np && (mode&NV_ADD))
1015 	{
1016 		if(sh.namespace && !(mode&HASH_NOSCOPE) && root==sh.var_tree)
1017 			root = nv_dict(sh.namespace);
1018 		else if(!dp && !(mode&HASH_NOSCOPE))
1019 		{
1020 			register Dt_t *next;
1021 			while(next=dtvnext(root))
1022 				root = next;
1023 		}
1024 		np = (Namval_t*)dtinsert(root,newnode(name));
1025 	}
1026 	if(dp)
1027 		dtview(root,dp);
1028 	return(np);
1029 }
1030 
1031 /*
1032  * finds function or builtin for given name and the discipline variable
1033  * if var!=0 the variable pointer is returned and the built-in name
1034  *    is put onto the stack at the current offset.
1035  * otherwise, a pointer to the builtin (variable or type) is returned
1036  * and var contains the poiner to the variable
1037  * if last==0 and first component of name is a reference, nv_bfsearch()
1038 	will return 0.
1039  */
1040 Namval_t *nv_bfsearch(const char *name, Dt_t *root, Namval_t **var, char **last)
1041 {
1042 	int		c,offset = staktell();
1043 	register char	*sp, *cp=0;
1044 	Namval_t	*np, *nq;
1045 	char		*dname=0;
1046 	if(var)
1047 		*var = 0;
1048 	/* check for . in the name before = */
1049 	for(sp=(char*)name+1; *sp; sp++)
1050 	{
1051 		if(*sp=='=')
1052 			return(0);
1053 		if(*sp=='[')
1054 		{
1055 			if(sp[-1]!='.')
1056 				dname = sp;
1057 			while(*sp=='[')
1058 			{
1059 				sp = nv_endsubscript((Namval_t*)0,(char*)sp,0);
1060 				if(sp[-1]!=']')
1061 					return(0);
1062 			}
1063 			if(*sp==0)
1064 				break;
1065 			if(*sp!='.')
1066 				return(0);
1067 			if(dname)
1068 			{
1069 				cp = dname;
1070 				dname = sp+1;
1071 			}
1072 		}
1073 		else if(*sp=='.')
1074 			cp = sp;
1075 	}
1076 	if(!cp)
1077 		return(var?nv_search(name,root,0):0);
1078 	stakputs(name);
1079 	stakputc(0);
1080 	if(!dname)
1081 		dname = cp+1;
1082 	cp = stakptr(offset) + (cp-name);
1083 	if(last)
1084 		*last = cp;
1085 	c = *cp;
1086 	*cp = 0;
1087 	nq=nv_open(stakptr(offset),0,NV_VARNAME|NV_ARRAY|NV_NOASSIGN|NV_NOADD|NV_NOFAIL);
1088 	*cp = c;
1089 	if(!nq)
1090 	{
1091 		np = 0;
1092 		goto done;
1093 	}
1094 	if(!var)
1095 	{
1096 		np = nq;
1097 		goto done;
1098 	}
1099 	*var = nq;
1100 	if(c=='[')
1101 		nv_endsubscript(nq, cp,NV_NOADD);
1102 	return((Namval_t*)nv_setdisc(nq,dname,nq,(Namfun_t*)nq));
1103 done:
1104 	stakseek(offset);
1105 	return(np);
1106 }
1107 
1108 /*
1109  * add or replace built-in version of command corresponding to <path>
1110  * The <bltin> argument is a pointer to the built-in
1111  * if <extra>==1, the built-in will be deleted
1112  * Special builtins cannot be added or deleted return failure
1113  * The return value for adding builtins is a pointer to the node or NULL on
1114  *   failure.  For delete NULL means success and the node that cannot be
1115  *   deleted is returned on failure.
1116  */
1117 Namval_t *sh_addbuiltin(const char *path, int (*bltin)(int, char*[],void*),void *extra)
1118 {
1119 	register const char	*name = path_basename(path);
1120 	char			*cp;
1121 	register Namval_t	*np, *nq=0;
1122 	int			offset=staktell();
1123 	if(name==path && (nq=nv_bfsearch(name,sh.bltin_tree,(Namval_t**)0,&cp)))
1124 		path = name = stakptr(offset);
1125 	if(np = nv_search(path,sh.bltin_tree,0))
1126 	{
1127 		/* exists without a path */
1128 		if(extra == (void*)1)
1129 		{
1130 			if(np->nvfun && !nv_isattr(np,NV_NOFREE))
1131 				free((void*)np->nvfun);
1132 			dtdelete(sh.bltin_tree,np);
1133 			return(0);
1134 		}
1135 		if(!bltin)
1136 			return(np);
1137 	}
1138 	else for(np=(Namval_t*)dtfirst(sh.bltin_tree);np;np=(Namval_t*)dtnext(sh.bltin_tree,np))
1139 	{
1140 		if(strcmp(name,path_basename(nv_name(np))))
1141 			continue;
1142 		/* exists probably with different path so delete it */
1143 		if(strcmp(path,nv_name(np)))
1144 		{
1145 			if(nv_isattr(np,BLT_SPC))
1146 				return(np);
1147 			if(!bltin)
1148 				bltin = np->nvalue.bfp;
1149 			if(np->nvenv)
1150 				dtdelete(sh.bltin_tree,np);
1151 			if(extra == (void*)1)
1152 				return(0);
1153 			np = 0;
1154 		}
1155 		break;
1156 	}
1157 	if(!np && !(np = nv_search(path,sh.bltin_tree,bltin?NV_ADD:0)))
1158 		return(0);
1159 	if(nv_isattr(np,BLT_SPC))
1160 	{
1161 		if(extra)
1162 			np->nvfun = (Namfun_t*)extra;
1163 		return(np);
1164 	}
1165 	np->nvenv = 0;
1166 	np->nvfun = 0;
1167 	if(bltin)
1168 	{
1169 		np->nvalue.bfp = bltin;
1170 		nv_onattr(np,NV_BLTIN|NV_NOFREE);
1171 		np->nvfun = (Namfun_t*)extra;
1172 	}
1173 	if(nq)
1174 	{
1175 		cp=nv_setdisc(nq,cp+1,np,(Namfun_t*)nq);
1176 		nv_close(nq);
1177 		if(!cp)
1178 			errormsg(SH_DICT,ERROR_exit(1),e_baddisc,name);
1179 	}
1180 	if(extra == (void*)1)
1181 		return(0);
1182 	return(np);
1183 }
1184 
1185 #undef nv_stack
1186 extern Namfun_t *nv_stack(register Namval_t *np, register Namfun_t* fp)
1187 {
1188 	return(nv_disc(np,fp,0));
1189 }
1190 
1191 struct table
1192 {
1193 	Namfun_t	fun;
1194 	Namval_t	*parent;
1195 	Shell_t		*shp;
1196 	Dt_t		*dict;
1197 };
1198 
1199 static Namval_t *next_table(register Namval_t* np, Dt_t *root,Namfun_t *fp)
1200 {
1201 	struct table *tp = (struct table *)fp;
1202 	if(root)
1203 		return((Namval_t*)dtnext(root,np));
1204 	else
1205 		return((Namval_t*)dtfirst(tp->dict));
1206 }
1207 
1208 static Namval_t *create_table(Namval_t *np,const char *name,int flags,Namfun_t *fp)
1209 {
1210 	struct table *tp = (struct table *)fp;
1211 	tp->shp->last_table = np;
1212 	return(nv_create(name, tp->dict, flags, fp));
1213 }
1214 
1215 static Namfun_t *clone_table(Namval_t* np, Namval_t *mp, int flags, Namfun_t *fp)
1216 {
1217 	struct table	*tp = (struct table*)fp;
1218 	struct table	*ntp = (struct table*)nv_clone_disc(fp,0);
1219 	Dt_t		*oroot=tp->dict,*nroot=dtopen(&_Nvdisc,Dtoset);
1220 	if(!nroot)
1221 		return(0);
1222 	memcpy((void*)ntp,(void*)fp,sizeof(struct table));
1223 	ntp->dict = nroot;
1224 	ntp->parent = nv_lastdict();
1225 	for(np=(Namval_t*)dtfirst(oroot);np;np=(Namval_t*)dtnext(oroot,np))
1226 	{
1227 		mp = (Namval_t*)dtinsert(nroot,newnode(np->nvname));
1228 		nv_clone(np,mp,flags);
1229 	}
1230 	return(&ntp->fun);
1231 }
1232 
1233 static void put_table(register Namval_t* np, const char* val, int flags, Namfun_t* fp)
1234 {
1235 	register Dt_t		*root = ((struct table*)fp)->dict;
1236 	register Namval_t	*nq, *mp;
1237 	Namarr_t		*ap;
1238 	nv_putv(np,val,flags,fp);
1239 	if(val)
1240 		return;
1241 	if(nv_isarray(np) && (ap=nv_arrayptr(np)) && array_elem(ap))
1242 		return;
1243 	for(mp=(Namval_t*)dtfirst(root);mp;mp=nq)
1244 	{
1245 		_nv_unset(mp,flags);
1246 		nq = (Namval_t*)dtnext(root,mp);
1247 		dtdelete(root,mp);
1248 		free((void*)mp);
1249 	}
1250 	dtclose(root);
1251 	if(!(fp->nofree&1))
1252 		free((void*)fp);
1253 }
1254 
1255 /*
1256  * return space separated list of names of variables in given tree
1257  */
1258 static char *get_table(Namval_t *np, Namfun_t *fp)
1259 {
1260 	register Dt_t *root = ((struct table*)fp)->dict;
1261 	static Sfio_t *out;
1262 	register int first=1;
1263 	register Dt_t *base = dtview(root,0);
1264         if(out)
1265                 sfseek(out,(Sfoff_t)0,SEEK_SET);
1266         else
1267                 out =  sfnew((Sfio_t*)0,(char*)0,-1,-1,SF_WRITE|SF_STRING);
1268 	for(np=(Namval_t*)dtfirst(root);np;np=(Namval_t*)dtnext(root,np))
1269 	{
1270                 if(!nv_isnull(np) || np->nvfun || nv_isattr(np,~NV_NOFREE))
1271 		{
1272 			if(!first)
1273 				sfputc(out,' ');
1274 			else
1275 				first = 0;
1276 			sfputr(out,np->nvname,-1);
1277 		}
1278 	}
1279 	sfputc(out,0);
1280 	if(base)
1281 		dtview(root,base);
1282 	return((char*)out->_data);
1283 }
1284 
1285 static const Namdisc_t table_disc =
1286 {
1287         sizeof(struct table),
1288         put_table,
1289         get_table,
1290         0,
1291         0,
1292         create_table,
1293         clone_table,
1294         0,
1295         next_table,
1296 };
1297 
1298 Namval_t *nv_parent(Namval_t *np)
1299 {
1300 	struct table *tp = (struct table *)nv_hasdisc(np,&table_disc);
1301 	if(tp)
1302 		return(tp->parent);
1303 	return(0);
1304 }
1305 
1306 Dt_t *nv_dict(Namval_t* np)
1307 {
1308 	struct table *tp = (struct table*)nv_hasdisc(np,&table_disc);
1309 	if(tp)
1310 		return(tp->dict);
1311 	np = sh.last_table;
1312 	while(np)
1313 	{
1314 		if(tp = (struct table*)nv_hasdisc(np,&table_disc))
1315 			return(tp->dict);
1316 #if 0
1317 		np = nv_create(np,(const char*)0, NV_FIRST, (Namfun_t*)0);
1318 #else
1319 		break;
1320 #endif
1321 	}
1322 	return(sh.var_tree);
1323 }
1324 
1325 /*
1326  * create a mountable name-value pair tree
1327  */
1328 Namval_t *nv_mount(Namval_t *np, const char *name, Dt_t *dict)
1329 {
1330 	Namval_t *mp, *pp=0;
1331 	struct table *tp = newof((struct table*)0, struct table,1,0);
1332 	if(name)
1333 	{
1334 		if(nv_istable(np))
1335 			pp = np;
1336 		else
1337 			pp = nv_lastdict();
1338 	}
1339 	if(!(tp = newof((struct table*)0, struct table,1,0)))
1340 		return(0);
1341 	if(name)
1342 	{
1343 		Namfun_t *fp = pp->nvfun;
1344 		mp = (*fp->disc->createf)(pp,name,0,fp);
1345 	}
1346 	else
1347 		mp = np;
1348 	if(!nv_isnull(mp))
1349 		nv_unset(mp);
1350 	tp->shp = sh_getinterp();
1351 	tp->dict = dict;
1352 	tp->parent = pp;
1353 	tp->fun.disc = &table_disc;
1354 	nv_onattr(mp,NV_TABLE);
1355 	nv_disc(mp, &tp->fun, NV_FIRST);
1356 	return(mp);
1357 }
1358 
1359 const Namdisc_t *nv_discfun(int which)
1360 {
1361 	switch(which)
1362 	{
1363 	    case NV_DCADD:
1364 		return(&Nv_bdisc);
1365 	    case NV_DCRESTRICT:
1366 		return(&RESTRICTED_disc);
1367 	}
1368 	return(0);
1369 }
1370 
1371