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