xref: /openbsd-src/bin/csh/set.c (revision 09e94acb64bd8cd95b21288efb30e4078c608ce0)
1 /*	$OpenBSD: set.c,v 1.2 1996/06/23 14:19:30 deraadt Exp $	*/
2 /*	$NetBSD: set.c,v 1.8 1995/03/21 18:35:52 mycroft Exp $	*/
3 
4 /*-
5  * Copyright (c) 1980, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)set.c	8.1 (Berkeley) 5/31/93";
40 #else
41 static char rcsid[] = "$OpenBSD: set.c,v 1.2 1996/06/23 14:19:30 deraadt Exp $";
42 #endif
43 #endif /* not lint */
44 
45 #include <sys/types.h>
46 #include <stdlib.h>
47 #ifndef SHORT_STRINGS
48 #include <string.h>
49 #endif /* SHORT_STRINGS */
50 #if __STDC__
51 # include <stdarg.h>
52 #else
53 # include <varargs.h>
54 #endif
55 
56 #include "csh.h"
57 #include "extern.h"
58 
59 static Char	*getinx __P((Char *, int *));
60 static void	 asx __P((Char *, int, Char *));
61 static struct varent
62 		*getvx __P((Char *, int));
63 static Char	*xset __P((Char *, Char ***));
64 static Char	*operate __P((int, Char *, Char *));
65 static void	 putn1 __P((int));
66 static struct varent
67 		*madrof __P((Char *, struct varent *));
68 static void	 unsetv1 __P((struct varent *));
69 static void	 exportpath __P((Char **));
70 static void	 balance __P((struct varent *, int, int));
71 
72 
73 /*
74  * C Shell
75  */
76 
77 void
78 /*ARGSUSED*/
79 doset(v, t)
80     Char **v;
81     struct command *t;
82 {
83     register Char *p;
84     Char   *vp, op;
85     Char  **vecp;
86     bool    hadsub;
87     int     subscr;
88 
89     v++;
90     p = *v++;
91     if (p == 0) {
92 	prvars();
93 	return;
94     }
95     do {
96 	hadsub = 0;
97 	vp = p;
98 	if (letter(*p))
99 	    for (; alnum(*p); p++)
100 		continue;
101 	if (vp == p || !letter(*vp))
102 	    stderror(ERR_NAME | ERR_VARBEGIN);
103 	if ((p - vp) > MAXVARLEN) {
104 	    stderror(ERR_NAME | ERR_VARTOOLONG);
105 	    return;
106 	}
107 	if (*p == '[') {
108 	    hadsub++;
109 	    p = getinx(p, &subscr);
110 	}
111 	if ((op = *p) != '\0') {
112 	    *p++ = 0;
113 	    if (*p == 0 && *v && **v == '(')
114 		p = *v++;
115 	}
116 	else if (*v && eq(*v, STRequal)) {
117 	    op = '=', v++;
118 	    if (*v)
119 		p = *v++;
120 	}
121 	if (op && op != '=')
122 	    stderror(ERR_NAME | ERR_SYNTAX);
123 	if (eq(p, STRLparen)) {
124 	    register Char **e = v;
125 
126 	    if (hadsub)
127 		stderror(ERR_NAME | ERR_SYNTAX);
128 	    for (;;) {
129 		if (!*e)
130 		    stderror(ERR_NAME | ERR_MISSING, ')');
131 		if (**e == ')')
132 		    break;
133 		e++;
134 	    }
135 	    p = *e;
136 	    *e = 0;
137 	    vecp = saveblk(v);
138 	    set1(vp, vecp, &shvhed);
139 	    *e = p;
140 	    v = e + 1;
141 	}
142 	else if (hadsub)
143 	    asx(vp, subscr, Strsave(p));
144 	else
145 	    set(vp, Strsave(p));
146 	if (eq(vp, STRpath)) {
147 	    exportpath(adrof(STRpath)->vec);
148 	    dohash(NULL, NULL);
149 	}
150 	else if (eq(vp, STRhistchars)) {
151 	    register Char *pn = value(STRhistchars);
152 
153 	    HIST = *pn++;
154 	    HISTSUB = *pn;
155 	}
156 	else if (eq(vp, STRuser)) {
157 	    Setenv(STRUSER, value(vp));
158 	    Setenv(STRLOGNAME, value(vp));
159 	}
160 	else if (eq(vp, STRwordchars)) {
161 	    word_chars = value(vp);
162 	}
163 	else if (eq(vp, STRterm))
164 	    Setenv(STRTERM, value(vp));
165 	else if (eq(vp, STRhome)) {
166 	    register Char *cp;
167 
168 	    cp = Strsave(value(vp));	/* get the old value back */
169 
170 	    /*
171 	     * convert to cononical pathname (possibly resolving symlinks)
172 	     */
173 	    cp = dcanon(cp, cp);
174 
175 	    set(vp, Strsave(cp));	/* have to save the new val */
176 
177 	    /* and now mirror home with HOME */
178 	    Setenv(STRHOME, cp);
179 	    /* fix directory stack for new tilde home */
180 	    dtilde();
181 	    xfree((ptr_t) cp);
182 	}
183 #ifdef FILEC
184 	else if (eq(vp, STRfilec))
185 	    filec = 1;
186 #endif
187     } while ((p = *v++) != NULL);
188 }
189 
190 static Char *
191 getinx(cp, ip)
192     register Char *cp;
193     register int *ip;
194 {
195 
196     *ip = 0;
197     *cp++ = 0;
198     while (*cp && Isdigit(*cp))
199 	*ip = *ip * 10 + *cp++ - '0';
200     if (*cp++ != ']')
201 	stderror(ERR_NAME | ERR_SUBSCRIPT);
202     return (cp);
203 }
204 
205 static void
206 asx(vp, subscr, p)
207     Char   *vp;
208     int     subscr;
209     Char   *p;
210 {
211     register struct varent *v = getvx(vp, subscr);
212 
213     xfree((ptr_t) v->vec[subscr - 1]);
214     v->vec[subscr - 1] = globone(p, G_APPEND);
215 }
216 
217 static struct varent *
218 getvx(vp, subscr)
219     Char   *vp;
220     int     subscr;
221 {
222     register struct varent *v = adrof(vp);
223 
224     if (v == 0)
225 	udvar(vp);
226     if (subscr < 1 || subscr > blklen(v->vec))
227 	stderror(ERR_NAME | ERR_RANGE);
228     return (v);
229 }
230 
231 void
232 /*ARGSUSED*/
233 dolet(v, t)
234     Char **v;
235     struct command *t;
236 {
237     register Char *p;
238     Char   *vp, c, op;
239     bool    hadsub;
240     int     subscr;
241 
242     v++;
243     p = *v++;
244     if (p == 0) {
245 	prvars();
246 	return;
247     }
248     do {
249 	hadsub = 0;
250 	vp = p;
251 	if (letter(*p))
252 	    for (; alnum(*p); p++)
253 		continue;
254 	if (vp == p || !letter(*vp))
255 	    stderror(ERR_NAME | ERR_VARBEGIN);
256 	if ((p - vp) > MAXVARLEN)
257 	    stderror(ERR_NAME | ERR_VARTOOLONG);
258 	if (*p == '[') {
259 	    hadsub++;
260 	    p = getinx(p, &subscr);
261 	}
262 	if (*p == 0 && *v)
263 	    p = *v++;
264 	if ((op = *p) != '\0')
265 	    *p++ = 0;
266 	else
267 	    stderror(ERR_NAME | ERR_ASSIGN);
268 
269 	if (*p == '\0' && *v == NULL)
270 	    stderror(ERR_NAME | ERR_ASSIGN);
271 
272 	vp = Strsave(vp);
273 	if (op == '=') {
274 	    c = '=';
275 	    p = xset(p, &v);
276 	}
277 	else {
278 	    c = *p++;
279 	    if (any("+-", c)) {
280 		if (c != op || *p)
281 		    stderror(ERR_NAME | ERR_UNKNOWNOP);
282 		p = Strsave(STR1);
283 	    }
284 	    else {
285 		if (any("<>", op)) {
286 		    if (c != op)
287 			stderror(ERR_NAME | ERR_UNKNOWNOP);
288 		    c = *p++;
289 		    stderror(ERR_NAME | ERR_SYNTAX);
290 		}
291 		if (c != '=')
292 		    stderror(ERR_NAME | ERR_UNKNOWNOP);
293 		p = xset(p, &v);
294 	    }
295 	}
296 	if (op == '=')
297 	    if (hadsub)
298 		asx(vp, subscr, p);
299 	    else
300 		set(vp, p);
301 	else if (hadsub) {
302 	    struct varent *gv = getvx(vp, subscr);
303 
304 	    asx(vp, subscr, operate(op, gv->vec[subscr - 1], p));
305 	}
306 	else
307 	    set(vp, operate(op, value(vp), p));
308 	if (eq(vp, STRpath)) {
309 	    exportpath(adrof(STRpath)->vec);
310 	    dohash(NULL, NULL);
311 	}
312 	xfree((ptr_t) vp);
313 	if (c != '=')
314 	    xfree((ptr_t) p);
315     } while ((p = *v++) != NULL);
316 }
317 
318 static Char *
319 xset(cp, vp)
320     Char   *cp, ***vp;
321 {
322     register Char *dp;
323 
324     if (*cp) {
325 	dp = Strsave(cp);
326 	--(*vp);
327 	xfree((ptr_t) ** vp);
328 	**vp = dp;
329     }
330     return (putn(expr(vp)));
331 }
332 
333 static Char *
334 operate(op, vp, p)
335     int    op;
336     Char  *vp, *p;
337 {
338     Char    opr[2];
339     Char   *vec[5];
340     register Char **v = vec;
341     Char  **vecp = v;
342     register int i;
343 
344     if (op != '=') {
345 	if (*vp)
346 	    *v++ = vp;
347 	opr[0] = op;
348 	opr[1] = 0;
349 	*v++ = opr;
350 	if (op == '<' || op == '>')
351 	    *v++ = opr;
352     }
353     *v++ = p;
354     *v++ = 0;
355     i = expr(&vecp);
356     if (*vecp)
357 	stderror(ERR_NAME | ERR_EXPRESSION);
358     return (putn(i));
359 }
360 
361 static Char *putp;
362 
363 Char   *
364 putn(n)
365     register int n;
366 {
367     int     num;
368     static Char number[15];
369 
370     putp = number;
371     if (n < 0) {
372 	n = -n;
373 	*putp++ = '-';
374     }
375     num = 2;			/* confuse lint */
376     if (sizeof(int) == num && ((unsigned int) n) == 0x8000) {
377 	*putp++ = '3';
378 	n = 2768;
379 #ifdef pdp11
380     }
381 #else
382     }
383     else {
384 	num = 4;		/* confuse lint */
385 	if (sizeof(int) == num && ((unsigned int) n) == 0x80000000) {
386 	    *putp++ = '2';
387 	    n = 147483648;
388 	}
389     }
390 #endif
391     putn1(n);
392     *putp = 0;
393     return (Strsave(number));
394 }
395 
396 static void
397 putn1(n)
398     register int n;
399 {
400     if (n > 9)
401 	putn1(n / 10);
402     *putp++ = n % 10 + '0';
403 }
404 
405 int
406 getn(cp)
407     register Char *cp;
408 {
409     register int n;
410     int     sign;
411 
412     sign = 0;
413     if (cp[0] == '+' && cp[1])
414 	cp++;
415     if (*cp == '-') {
416 	sign++;
417 	cp++;
418 	if (!Isdigit(*cp))
419 	    stderror(ERR_NAME | ERR_BADNUM);
420     }
421     n = 0;
422     while (Isdigit(*cp))
423 	n = n * 10 + *cp++ - '0';
424     if (*cp)
425 	stderror(ERR_NAME | ERR_BADNUM);
426     return (sign ? -n : n);
427 }
428 
429 Char   *
430 value1(var, head)
431     Char   *var;
432     struct varent *head;
433 {
434     register struct varent *vp;
435 
436     vp = adrof1(var, head);
437     return (vp == 0 || vp->vec[0] == 0 ? STRNULL : vp->vec[0]);
438 }
439 
440 static struct varent *
441 madrof(pat, vp)
442     Char   *pat;
443     register struct varent *vp;
444 {
445     register struct varent *vp1;
446 
447     for (; vp; vp = vp->v_right) {
448 	if (vp->v_left && (vp1 = madrof(pat, vp->v_left)))
449 	    return vp1;
450 	if (Gmatch(vp->v_name, pat))
451 	    return vp;
452     }
453     return vp;
454 }
455 
456 struct varent *
457 adrof1(name, v)
458     register Char *name;
459     register struct varent *v;
460 {
461     register cmp;
462 
463     v = v->v_left;
464     while (v && ((cmp = *name - *v->v_name) ||
465 		 (cmp = Strcmp(name, v->v_name))))
466 	if (cmp < 0)
467 	    v = v->v_left;
468 	else
469 	    v = v->v_right;
470     return v;
471 }
472 
473 /*
474  * The caller is responsible for putting value in a safe place
475  */
476 void
477 set(var, val)
478     Char   *var, *val;
479 {
480     register Char **vec = (Char **) xmalloc((size_t) (2 * sizeof(Char **)));
481 
482     vec[0] = val;
483     vec[1] = 0;
484     set1(var, vec, &shvhed);
485 }
486 
487 void
488 set1(var, vec, head)
489     Char   *var, **vec;
490     struct varent *head;
491 {
492     register Char **oldv = vec;
493 
494     gflag = 0;
495     tglob(oldv);
496     if (gflag) {
497 	vec = globall(oldv);
498 	if (vec == 0) {
499 	    blkfree(oldv);
500 	    stderror(ERR_NAME | ERR_NOMATCH);
501 	    return;
502 	}
503 	blkfree(oldv);
504 	gargv = 0;
505     }
506     setq(var, vec, head);
507 }
508 
509 
510 void
511 setq(name, vec, p)
512     Char   *name, **vec;
513     register struct varent *p;
514 {
515     register struct varent *c;
516     register f;
517 
518     f = 0;			/* tree hangs off the header's left link */
519     while ((c = p->v_link[f]) != NULL) {
520 	if ((f = *name - *c->v_name) == 0 &&
521 	    (f = Strcmp(name, c->v_name)) == 0) {
522 	    blkfree(c->vec);
523 	    goto found;
524 	}
525 	p = c;
526 	f = f > 0;
527     }
528     p->v_link[f] = c = (struct varent *) xmalloc((size_t) sizeof(struct varent));
529     c->v_name = Strsave(name);
530     c->v_bal = 0;
531     c->v_left = c->v_right = 0;
532     c->v_parent = p;
533     balance(p, f, 0);
534 found:
535     trim(c->vec = vec);
536 }
537 
538 void
539 /*ARGSUSED*/
540 unset(v, t)
541     Char **v;
542     struct command *t;
543 {
544     unset1(v, &shvhed);
545 #ifdef FILEC
546     if (adrof(STRfilec) == 0)
547 	filec = 0;
548 #endif
549     if (adrof(STRhistchars) == 0) {
550 	HIST = '!';
551 	HISTSUB = '^';
552     }
553     if (adrof(STRwordchars) == 0)
554 	word_chars = STR_WORD_CHARS;
555 }
556 
557 void
558 unset1(v, head)
559     register Char *v[];
560     struct varent *head;
561 {
562     register struct varent *vp;
563     register int cnt;
564 
565     while (*++v) {
566 	cnt = 0;
567 	while ((vp = madrof(*v, head->v_left)) != NULL)
568 	    unsetv1(vp), cnt++;
569 	if (cnt == 0)
570 	    setname(vis_str(*v));
571     }
572 }
573 
574 void
575 unsetv(var)
576     Char   *var;
577 {
578     register struct varent *vp;
579 
580     if ((vp = adrof1(var, &shvhed)) == 0)
581 	udvar(var);
582     unsetv1(vp);
583 }
584 
585 static void
586 unsetv1(p)
587     register struct varent *p;
588 {
589     register struct varent *c, *pp;
590     register f;
591 
592     /*
593      * Free associated memory first to avoid complications.
594      */
595     blkfree(p->vec);
596     xfree((ptr_t) p->v_name);
597     /*
598      * If p is missing one child, then we can move the other into where p is.
599      * Otherwise, we find the predecessor of p, which is guaranteed to have no
600      * right child, copy it into p, and move it's left child into it.
601      */
602     if (p->v_right == 0)
603 	c = p->v_left;
604     else if (p->v_left == 0)
605 	c = p->v_right;
606     else {
607 	for (c = p->v_left; c->v_right; c = c->v_right)
608 	    continue;
609 	p->v_name = c->v_name;
610 	p->vec = c->vec;
611 	p = c;
612 	c = p->v_left;
613     }
614     /*
615      * Move c into where p is.
616      */
617     pp = p->v_parent;
618     f = pp->v_right == p;
619     if ((pp->v_link[f] = c) != NULL)
620 	c->v_parent = pp;
621     /*
622      * Free the deleted node, and rebalance.
623      */
624     xfree((ptr_t) p);
625     balance(pp, f, 1);
626 }
627 
628 void
629 setNS(cp)
630     Char   *cp;
631 {
632     set(cp, Strsave(STRNULL));
633 }
634 
635 void
636 /*ARGSUSED*/
637 shift(v, t)
638     Char **v;
639     struct command *t;
640 {
641     register struct varent *argv;
642     register Char *name;
643 
644     v++;
645     name = *v;
646     if (name == 0)
647 	name = STRargv;
648     else
649 	(void) strip(name);
650     argv = adrof(name);
651     if (argv == 0)
652 	udvar(name);
653     if (argv->vec[0] == 0)
654 	stderror(ERR_NAME | ERR_NOMORE);
655     lshift(argv->vec, 1);
656 }
657 
658 static void
659 exportpath(val)
660     Char  **val;
661 {
662     Char    exppath[BUFSIZ];
663 
664     exppath[0] = 0;
665     if (val)
666 	while (*val) {
667 	    if (Strlen(*val) + Strlen(exppath) + 2 > BUFSIZ) {
668 		(void) fprintf(csherr,
669 			       "Warning: ridiculously long PATH truncated\n");
670 		break;
671 	    }
672 	    (void) Strcat(exppath, *val++);
673 	    if (*val == 0 || eq(*val, STRRparen))
674 		break;
675 	    (void) Strcat(exppath, STRcolon);
676 	}
677     Setenv(STRPATH, exppath);
678 }
679 
680 #ifndef lint
681  /*
682   * Lint thinks these have null effect
683   */
684  /* macros to do single rotations on node p */
685 #define rright(p) (\
686 	t = (p)->v_left,\
687 	(t)->v_parent = (p)->v_parent,\
688 	((p)->v_left = t->v_right) ? (t->v_right->v_parent = (p)) : 0,\
689 	(t->v_right = (p))->v_parent = t,\
690 	(p) = t)
691 #define rleft(p) (\
692 	t = (p)->v_right,\
693 	(t)->v_parent = (p)->v_parent,\
694 	((p)->v_right = t->v_left) ? (t->v_left->v_parent = (p)) : 0,\
695 	(t->v_left = (p))->v_parent = t,\
696 	(p) = t)
697 #else
698 struct varent *
699 rleft(p)
700     struct varent *p;
701 {
702     return (p);
703 }
704 struct varent *
705 rright(p)
706     struct varent *p;
707 {
708     return (p);
709 }
710 
711 #endif				/* ! lint */
712 
713 
714 /*
715  * Rebalance a tree, starting at p and up.
716  * F == 0 means we've come from p's left child.
717  * D == 1 means we've just done a delete, otherwise an insert.
718  */
719 static void
720 balance(p, f, d)
721     register struct varent *p;
722     register int f, d;
723 {
724     register struct varent *pp;
725 
726 #ifndef lint
727     register struct varent *t;	/* used by the rotate macros */
728 
729 #endif
730     register ff;
731 
732     /*
733      * Ok, from here on, p is the node we're operating on; pp is it's parent; f
734      * is the branch of p from which we have come; ff is the branch of pp which
735      * is p.
736      */
737     for (; (pp = p->v_parent) != NULL; p = pp, f = ff) {
738 	ff = pp->v_right == p;
739 	if (f ^ d) {		/* right heavy */
740 	    switch (p->v_bal) {
741 	    case -1:		/* was left heavy */
742 		p->v_bal = 0;
743 		break;
744 	    case 0:		/* was balanced */
745 		p->v_bal = 1;
746 		break;
747 	    case 1:		/* was already right heavy */
748 		switch (p->v_right->v_bal) {
749 		case 1:	/* sigle rotate */
750 		    pp->v_link[ff] = rleft(p);
751 		    p->v_left->v_bal = 0;
752 		    p->v_bal = 0;
753 		    break;
754 		case 0:	/* single rotate */
755 		    pp->v_link[ff] = rleft(p);
756 		    p->v_left->v_bal = 1;
757 		    p->v_bal = -1;
758 		    break;
759 		case -1:	/* double rotate */
760 		    (void) rright(p->v_right);
761 		    pp->v_link[ff] = rleft(p);
762 		    p->v_left->v_bal =
763 			p->v_bal < 1 ? 0 : -1;
764 		    p->v_right->v_bal =
765 			p->v_bal > -1 ? 0 : 1;
766 		    p->v_bal = 0;
767 		    break;
768 		}
769 		break;
770 	    }
771 	}
772 	else {			/* left heavy */
773 	    switch (p->v_bal) {
774 	    case 1:		/* was right heavy */
775 		p->v_bal = 0;
776 		break;
777 	    case 0:		/* was balanced */
778 		p->v_bal = -1;
779 		break;
780 	    case -1:		/* was already left heavy */
781 		switch (p->v_left->v_bal) {
782 		case -1:	/* single rotate */
783 		    pp->v_link[ff] = rright(p);
784 		    p->v_right->v_bal = 0;
785 		    p->v_bal = 0;
786 		    break;
787 		case 0:	/* signle rotate */
788 		    pp->v_link[ff] = rright(p);
789 		    p->v_right->v_bal = -1;
790 		    p->v_bal = 1;
791 		    break;
792 		case 1:	/* double rotate */
793 		    (void) rleft(p->v_left);
794 		    pp->v_link[ff] = rright(p);
795 		    p->v_left->v_bal =
796 			p->v_bal < 1 ? 0 : -1;
797 		    p->v_right->v_bal =
798 			p->v_bal > -1 ? 0 : 1;
799 		    p->v_bal = 0;
800 		    break;
801 		}
802 		break;
803 	    }
804 	}
805 	/*
806 	 * If from insert, then we terminate when p is balanced. If from
807 	 * delete, then we terminate when p is unbalanced.
808 	 */
809 	if ((p->v_bal == 0) ^ d)
810 	    break;
811     }
812 }
813 
814 void
815 plist(p)
816     register struct varent *p;
817 {
818     register struct varent *c;
819     register len;
820     sigset_t sigset;
821 
822     if (setintr) {
823 	sigemptyset(&sigset);
824 	sigaddset(&sigset, SIGINT);
825 	sigprocmask(SIG_UNBLOCK, &sigset, NULL);
826     }
827 
828     for (;;) {
829 	while (p->v_left)
830 	    p = p->v_left;
831 x:
832 	if (p->v_parent == 0)	/* is it the header? */
833 	    return;
834 	len = blklen(p->vec);
835 	(void) fprintf(cshout, "%s\t", short2str(p->v_name));
836 	if (len != 1)
837 	    (void) fputc('(', cshout);
838 	blkpr(cshout, p->vec);
839 	if (len != 1)
840 	    (void) fputc(')', cshout);
841 	(void) fputc('\n', cshout);
842 	if (p->v_right) {
843 	    p = p->v_right;
844 	    continue;
845 	}
846 	do {
847 	    c = p;
848 	    p = p->v_parent;
849 	} while (p->v_right == c);
850 	goto x;
851     }
852 }
853