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 */
28 posix_tnode *
tfind(const void * vkey,posix_tnode * const * rootp,int (* compar)(const void *,const void *))29 tfind(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