1/*	$NetBSD: tfind.c,v 1.2 1999/09/16 11:45:37 lukem Exp $	*/
2
3/*
4 * Tree search generalized from Knuth (6.2.2) Algorithm T just like
5 * the AT&T man page says.
6 *
7 * The node_t structure is for internal use only, lint doesn't grok it.
8 *
9 * Written by reading the System V Interface Definition, not the code.
10 *
11 * Totally public domain.
12 */
13
14#include <sys/cdefs.h>
15#if 0
16#if defined(LIBC_SCCS) && !defined(lint)
17__RCSID("$NetBSD: tfind.c,v 1.2 1999/09/16 11:45:37 lukem Exp $");
18#endif /* LIBC_SCCS and not lint */
19#endif
20__FBSDID("$FreeBSD$");
21
22#define _SEARCH_PRIVATE
23#include <stdlib.h>
24#include <search.h>
25
26/*
27 * find a node, or return 0
28 *
29 * vkey   - key to be found
30 * vrootp - address of the tree root
31 */
32void *
33tfind(const void *vkey, void * const *vrootp,
34    int (*compar)(const void *, const void *))
35{
36	node_t **rootp = (node_t **)vrootp;
37
38	if (rootp == NULL)
39		return NULL;
40
41	while (*rootp != NULL) {		/* T1: */
42		int r;
43
44		if ((r = (*compar)(vkey, (*rootp)->key)) == 0)	/* T2: */
45			return *rootp;		/* key found */
46		rootp = (r < 0) ?
47		    &(*rootp)->llink :		/* T3: follow left branch */
48		    &(*rootp)->rlink;		/* T4: follow right branch */
49	}
50	return NULL;
51}
52