2 * CDE - Common Desktop Environment
4 * Copyright (c) 1993-2012, The Open Group. All rights reserved.
6 * These libraries and programs are free software; you can
7 * redistribute them and/or modify them under the terms of the GNU
8 * Lesser General Public License as published by the Free Software
9 * Foundation; either version 2 of the License, or (at your option)
12 * These libraries and programs are distributed in the hope that
13 * they will be useful, but WITHOUT ANY WARRANTY; without even the
14 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
15 * PURPOSE. See the GNU Lesser General Public License for more
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with these libraries and programs; if not, write
20 * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
21 * Floor, Boston, MA 02110-1301 USA
23 /*%% (c) Copyright 1993, 1994 Hewlett-Packard Company */
24 /*%% (c) Copyright 1993, 1994 International Business Machines Corp. */
25 /*%% (c) Copyright 1993, 1994 Sun Microsystems, Inc. */
26 /*%% (c) Copyright 1993, 1994 Novell, Inc. */
27 /*%% $XConsortium: isbsearch.c /main/3 1995/10/23 11:35:44 rswiston $ */
29 static char sccsid[] = "@(#)isbsearch.c 1.3 89/07/17 Copyr 1988 Sun Micro";
33 * Copyright (c) 1988 by Sun Microsystems, Inc.
40 * Binary search function.
41 * If differs from bsearch(3) in that if an exact match is not found,
42 * the next lower key is returned. If key is lower than any key in table,
43 * NULL value is returned.
48 char *_isbsearch (char *key, char *table, int nelems, int keylen, int (*cmpf) ())
50 register int len,l1,result; /* current length of array to search */
51 register char *p,*low;
53 if (nelems <= 0) return (char *) 0;
55 /* Check if key is lower than any key in the table. */
56 result = (*cmpf) (key,table);
57 if (result < 0 ) return (char *) 0; /* Key is lower */
58 else if (result == 0) return table; /* Exact match */
60 for (low = table,len = nelems; len > 0;) {
62 p = low + keylen * l1;
63 if ((result = (*cmpf) (key,p)) == 0) /* Exact match found */
66 if (result > 0 ) { /* Key is in higher half */
70 else { /* Key is in lower half */
75 /* No matching key found, return next lower key */
76 return (result>0)?p:(p-keylen);