1*7c478bd9Sstevel@tonic-gate /* 2*7c478bd9Sstevel@tonic-gate * CDDL HEADER START 3*7c478bd9Sstevel@tonic-gate * 4*7c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*7c478bd9Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*7c478bd9Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*7c478bd9Sstevel@tonic-gate * with the License. 8*7c478bd9Sstevel@tonic-gate * 9*7c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*7c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*7c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 12*7c478bd9Sstevel@tonic-gate * and limitations under the License. 13*7c478bd9Sstevel@tonic-gate * 14*7c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*7c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*7c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*7c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*7c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*7c478bd9Sstevel@tonic-gate * 20*7c478bd9Sstevel@tonic-gate * CDDL HEADER END 21*7c478bd9Sstevel@tonic-gate */ 22*7c478bd9Sstevel@tonic-gate /* Copyright (c) 1984 AT&T */ 23*7c478bd9Sstevel@tonic-gate /* All Rights Reserved */ 24*7c478bd9Sstevel@tonic-gate 25*7c478bd9Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" /* from S5R2 1.5 */ 26*7c478bd9Sstevel@tonic-gate 27*7c478bd9Sstevel@tonic-gate /*LINTLIBRARY*/ 28*7c478bd9Sstevel@tonic-gate /* 29*7c478bd9Sstevel@tonic-gate * Binary search algorithm, generalized from Knuth (6.2.1) Algorithm B. 30*7c478bd9Sstevel@tonic-gate * 31*7c478bd9Sstevel@tonic-gate */ 32*7c478bd9Sstevel@tonic-gate 33*7c478bd9Sstevel@tonic-gate typedef char *POINTER; 34*7c478bd9Sstevel@tonic-gate 35*7c478bd9Sstevel@tonic-gate POINTER 36*7c478bd9Sstevel@tonic-gate bsearch(key, base, nel, width, compar) 37*7c478bd9Sstevel@tonic-gate POINTER key; /* Key to be located */ 38*7c478bd9Sstevel@tonic-gate POINTER base; /* Beginning of table */ 39*7c478bd9Sstevel@tonic-gate unsigned nel; /* Number of elements in the table */ 40*7c478bd9Sstevel@tonic-gate unsigned width; /* Width of an element (bytes) */ 41*7c478bd9Sstevel@tonic-gate int (*compar)(); /* Comparison function */ 42*7c478bd9Sstevel@tonic-gate { 43*7c478bd9Sstevel@tonic-gate int two_width = width + width; 44*7c478bd9Sstevel@tonic-gate POINTER last = base + width * (nel - 1); /* Last element in table */ 45*7c478bd9Sstevel@tonic-gate 46*7c478bd9Sstevel@tonic-gate while (last >= base) { 47*7c478bd9Sstevel@tonic-gate 48*7c478bd9Sstevel@tonic-gate register POINTER p = base + width * ((last - base)/two_width); 49*7c478bd9Sstevel@tonic-gate register int res = (*compar)(key, p); 50*7c478bd9Sstevel@tonic-gate 51*7c478bd9Sstevel@tonic-gate if (res == 0) 52*7c478bd9Sstevel@tonic-gate return (p); /* Key found */ 53*7c478bd9Sstevel@tonic-gate if (res < 0) 54*7c478bd9Sstevel@tonic-gate last = p - width; 55*7c478bd9Sstevel@tonic-gate else 56*7c478bd9Sstevel@tonic-gate base = p + width; 57*7c478bd9Sstevel@tonic-gate } 58*7c478bd9Sstevel@tonic-gate return ((POINTER) 0); /* Key not found */ 59*7c478bd9Sstevel@tonic-gate } 60