xref: /dflybsd-src/lib/libc/stdlib/twalk.c (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)
1*86d7f5d3SJohn Marino /*
2*86d7f5d3SJohn Marino  * Tree search generalized from Knuth (6.2.2) Algorithm T just like
3*86d7f5d3SJohn Marino  * the AT&T man page says.
4*86d7f5d3SJohn Marino  *
5*86d7f5d3SJohn Marino  * The node_t structure is for internal use only, lint doesn't grok it.
6*86d7f5d3SJohn Marino  *
7*86d7f5d3SJohn Marino  * Written by reading the System V Interface Definition, not the code.
8*86d7f5d3SJohn Marino  *
9*86d7f5d3SJohn Marino  * Totally public domain.
10*86d7f5d3SJohn Marino  *
11*86d7f5d3SJohn Marino  * $NetBSD: twalk.c,v 1.1 1999/02/22 10:33:16 christos Exp $
12*86d7f5d3SJohn Marino  * $FreeBSD: src/lib/libc/stdlib/twalk.c,v 1.5 2003/01/05 02:43:18 tjr Exp $
13*86d7f5d3SJohn Marino  * $DragonFly: src/lib/libc/stdlib/twalk.c,v 1.5 2005/11/24 17:18:30 swildner Exp $
14*86d7f5d3SJohn Marino  */
15*86d7f5d3SJohn Marino 
16*86d7f5d3SJohn Marino #define _SEARCH_PRIVATE
17*86d7f5d3SJohn Marino #include <search.h>
18*86d7f5d3SJohn Marino #include <stdlib.h>
19*86d7f5d3SJohn Marino 
20*86d7f5d3SJohn Marino static void trecurse(const node_t *,
21*86d7f5d3SJohn Marino 		     void (*action)(const void *, VISIT, int), int level);
22*86d7f5d3SJohn Marino 
23*86d7f5d3SJohn Marino /*
24*86d7f5d3SJohn Marino  * Walk the nodes of a tree
25*86d7f5d3SJohn Marino  *
26*86d7f5d3SJohn Marino  * Parameters:
27*86d7f5d3SJohn Marino  *	root:	Root of the tree to be walked
28*86d7f5d3SJohn Marino  */
29*86d7f5d3SJohn Marino static void
trecurse(const node_t * root,void (* action)(const void *,VISIT,int),int level)30*86d7f5d3SJohn Marino trecurse(const node_t *root, void (*action)(const void *, VISIT, int),
31*86d7f5d3SJohn Marino 	 int level)
32*86d7f5d3SJohn Marino {
33*86d7f5d3SJohn Marino 
34*86d7f5d3SJohn Marino 	if (root->llink == NULL && root->rlink == NULL)
35*86d7f5d3SJohn Marino 		(*action)(root, leaf, level);
36*86d7f5d3SJohn Marino 	else {
37*86d7f5d3SJohn Marino 		(*action)(root, preorder, level);
38*86d7f5d3SJohn Marino 		if (root->llink != NULL)
39*86d7f5d3SJohn Marino 			trecurse(root->llink, action, level + 1);
40*86d7f5d3SJohn Marino 		(*action)(root, postorder, level);
41*86d7f5d3SJohn Marino 		if (root->rlink != NULL)
42*86d7f5d3SJohn Marino 			trecurse(root->rlink, action, level + 1);
43*86d7f5d3SJohn Marino 		(*action)(root, endorder, level);
44*86d7f5d3SJohn Marino 	}
45*86d7f5d3SJohn Marino }
46*86d7f5d3SJohn Marino 
47*86d7f5d3SJohn Marino /*
48*86d7f5d3SJohn Marino  * Walk the nodes of a tree
49*86d7f5d3SJohn Marino  *
50*86d7f5d3SJohn Marino  * Parameters:
51*86d7f5d3SJohn Marino  *	vroot:	Root of the tree to be walked
52*86d7f5d3SJohn Marino  */
53*86d7f5d3SJohn Marino void
twalk(const void * vroot,void (* action)(const void *,VISIT,int))54*86d7f5d3SJohn Marino twalk(const void *vroot,
55*86d7f5d3SJohn Marino       void (*action)(const void *, VISIT, int))
56*86d7f5d3SJohn Marino {
57*86d7f5d3SJohn Marino 	if (vroot != NULL && action != NULL)
58*86d7f5d3SJohn Marino 		trecurse(vroot, action, 0);
59*86d7f5d3SJohn Marino }
60