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 $");
16 #endif /* LIBC_SCCS and not lint */
17 #endif
18 __FBSDID("$FreeBSD$");
19
20 #define _SEARCH_PRIVATE
21 #include <stdlib.h>
22 #include <search.h>
23
24 /*
25 * find a node, or return 0
26 *
27 * vkey - key to be found
28 * vrootp - address of the tree root
29 */
30 posix_tnode *
tfind(const void * vkey,posix_tnode * const * rootp,int (* compar)(const void *,const void *))31 tfind(const void *vkey, posix_tnode * const *rootp,
32 int (*compar)(const void *, const void *))
33 {
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