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 * Written by reading the System V Interface Definition, not the code.
8 *
9 * Totally public domain.
10 */
11
12#include <sys/cdefs.h>
13#if 0
14#if defined(LIBC_SCCS) && !defined(lint)
15__RCSID("$NetBSD: tfind.c,v 1.2 1999/09/16 11:45:37 lukem Exp $");
16#endif /* LIBC_SCCS and not lint */
17#endif
18#define _SEARCH_PRIVATE
19#include <stdlib.h>
20#include <search.h>
21
22/*
23 * find a node, or return 0
24 *
25 * vkey   - key to be found
26 * vrootp - address of the tree root
27 */
28posix_tnode *
29tfind(const void *vkey, posix_tnode * const *rootp,
30    int (*compar)(const void *, const void *))
31{
32
33	if (rootp == NULL)
34		return NULL;
35
36	while (*rootp != NULL) {		/* T1: */
37		int r;
38
39		if ((r = (*compar)(vkey, (*rootp)->key)) == 0)	/* T2: */
40			return *rootp;		/* key found */
41		rootp = (r < 0) ?
42		    &(*rootp)->llink :		/* T3: follow left branch */
43		    &(*rootp)->rlink;		/* T4: follow right branch */
44	}
45	return NULL;
46}
47