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/* Copyright (C) 1991,92,97,2000,02 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, write to the Free

   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA

   02111-1307 USA.  */

#include <stdlib.h>

/* Perform a binary search for KEY in BASE which has NMEMB elements

   of SIZE bytes each.  The comparisons are done by (*COMPAR)().  */

void *

bsearch (const void *key, const void *base, size_t nmemb, size_t size,

         int (*compar) (const void *, const void *))

{

  size_t l, u, idx;

  const void *p;

  int comparison;

  l = 0;

  u = nmemb;

  while (l < u)

    {

      idx = (l + u) / 2;

      p = (void *) (((const char *) base) + (idx * size));

      comparison = (*compar) (key, p);

      if (comparison < 0)

        u = idx;

      else if (comparison > 0)

        l = idx + 1;

      else

        return (void *) p;

    }

  return NULL;

}