1/* Copyright (C) 1991 Free Software Foundation, Inc. 2This file is part of the GNU C Library. 3 4The GNU C Library is free software; you can redistribute it and/or 5modify it under the terms of the GNU Library General Public License as 6published by the Free Software Foundation; either version 2 of the 7License, or (at your option) any later version. 8 9The GNU C Library is distributed in the hope that it will be useful, 10but WITHOUT ANY WARRANTY; without even the implied warranty of 11MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12Library General Public License for more details. 13 14You should have received a copy of the GNU Library General Public 15License along with the GNU C Library; see the file COPYING.LIB. If 16not, write to the Free Software Foundation, Inc., 59 Temple Place - 17Suite 330, Boston, MA 02111-1307, USA. 18 19This file was modified slightly by Ian Lance Taylor, May 1992, for 20Taylor UUCP. */ 21 22#include "uucp.h" 23 24/* Perform a binary search for KEY in BASE which has NMEMB elements 25 of SIZE bytes each. The comparisons are done by (*COMPAR)(). */ 26pointer 27bsearch (key, base, nmemb, size, compar) 28 register constpointer key; 29 register constpointer base; 30 size_t nmemb; 31 register size_t size; 32 register int (*compar) P((constpointer, constpointer)); 33{ 34 register size_t l, u, idx; 35 register constpointer p; 36 register int comparison; 37 38 l = 0; 39 u = nmemb; 40 while (l < u) 41 { 42 idx = (l + u) / 2; 43 p = (constpointer) (((const char *) base) + (idx * size)); 44 comparison = (*compar)(key, p); 45 if (comparison < 0) 46 u = idx; 47 else if (comparison > 0) 48 l = idx + 1; 49 else 50 return (pointer) p; 51 } 52 53 return NULL; 54} 55