external/bsd/am-utils/dist/libamu/memcmp.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (c) 1997-2009 Erez Zadok
   5  * Copyright (c) 1990 Jan-Simon Pendry
   6  * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
   7  * Copyright (c) 1990 The Regents of the University of California.
   8  * All rights reserved.
   9  *
  10  * This code is derived from software contributed to Berkeley by
  11  * Jan-Simon Pendry at Imperial College, London.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgment:
  23  *      This product includes software developed by the University of
  24  *      California, Berkeley and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  *
  41  *
  42  * File: am-utils/libamu/memcmp.c
  43  *
  44  */
  45
  46 #ifdef HAVE_CONFIG_H
  47 # include <config.h>
  48 #endif /* HAVE_CONFIG_H */
  49 #include <am_defs.h>
  50 #include <amu.h>
  51
  52
  53 /*
  54  * compare two strings for up to length "len".
  55  * this will normally be included on systems that either have no memcmp()
  56  * and no bcmp(), or on systems that have both but the memcmp() is not 8-bit
  57  * clean (such as SunOS 4.1.3).
  58  *
  59  * SunOS 4.x with gcc requires prototype of (const voidp, const voidp, size_t)
  60  */
  61 int
  62 am_memcmp(const voidp s1, const voidp s2, size_t len)
  63 {
  64   unsigned char *ucp1 = (unsigned char *) s1;
  65   unsigned char *ucp2 = (unsigned char *) s2;
  66   int i = len;
  67
  68   while (i-- > 0)
  69     if (*ucp1++ != *ucp2++)
  70       return (ucp1[-1] >= ucp2[-1] ? 1 : -1);
  71
  72   return 0;
  73 }