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/* find a node, or return 0 */
27void *
28tfind(vkey, vrootp, compar)
29	const void *vkey;		/* key to be found */
30	void * const *vrootp;		/* address of the tree root */
31	int (*compar)(const void *, const void *);
32{
33	node_t **rootp = (node_t **)vrootp;
34
35	if (rootp == NULL)
36		return NULL;
37
38	while (*rootp != NULL) {		/* T1: */
39		int r;
40
41		if ((r = (*compar)(vkey, (*rootp)->key)) == 0)	/* T2: */
42			return *rootp;		/* key found */
43		rootp = (r < 0) ?
44		    &(*rootp)->llink :		/* T3: follow left branch */
45		    &(*rootp)->rlink;		/* T4: follow right branch */
46	}
47	return NULL;
48}
49