/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI" /* from S5R2 1.2 */
/*LINTLIBRARY*/
/*
* Tree search algorithm, generalized from Knuth (6.2.2) Algorithm T.
*
* The NODE * arguments are declared in the lint files as char *,
* because the definition of NODE isn't available to the user.
*/
#include <search.h>
typedef char *POINTER;
typedef struct node { POINTER key; struct node *llink, *rlink; } NODE;
#define NULL 0
/* tfind - find a node, or return 0 */
NODE *
tfind(key, rootp, compar)
POINTER key; /* Key to be located */
register NODE **rootp; /* Address of the root of the tree */
int (*compar)(); /* Comparison function */
{
if (rootp == NULL)
return (NULL);
while (*rootp != NULL) { /* T1: */
int r = (*compar)(key, (*rootp)->key); /* T2: */
if (r == 0)
return (*rootp); /* Key found */
rootp = (r < 0) ?
&(*rootp)->llink : /* T3: Take left branch */
&(*rootp)->rlink; /* T4: Take right branch */
}
return (NODE *)(NULL);
}