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87 lines
2.6 KiB
C
87 lines
2.6 KiB
C
/*
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* endian - determine the byte order of a long on your machine
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*
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* Copyright (C) 1999 Landon Curt Noll
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*
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* Calc is open software; you can redistribute it and/or modify it under
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* the terms of the version 2.1 of the GNU Lesser General Public License
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* as published by the Free Software Foundation.
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*
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* Calc is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
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* Public License for more details.
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*
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* A copy of version 2.1 of the GNU Lesser General Public License is
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* distributed with calc under the filename COPYING-LGPL. You should have
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* received a copy with calc; if not, write to Free Software Foundation, Inc.
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
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*
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* @(#) $Revision: 29.1 $
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* @(#) $Id: endian.c,v 29.1 1999/12/14 09:15:37 chongo Exp $
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* @(#) $Source: /usr/local/src/cmd/calc/RCS/endian.c,v $
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*
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* Under source code control: 1993/11/15 04:32:58
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* File existed as early as: 1993
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*
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* chongo <was here> /\oo/\ http://reality.sgi.com/chongo/
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* Share and enjoy! :-) http://reality.sgi.com/chongo/tech/comp/calc/
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*/
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/*
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* Big Endian: Amdahl, 68k, Pyramid, Mips, Sparc, ...
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* Little Endian: Vax, 32k, Spim (Dec Mips), i386, i486, ...
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*/
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#include <stdio.h>
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#include "have_unistd.h"
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#if defined(HAVE_UNISTD_H)
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#include <unistd.h>
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#endif
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/* byte order array */
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char byte[8] = { (char)0x12, (char)0x36, (char)0x48, (char)0x59,
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(char)0x01, (char)0x23, (char)0x45, (char)0x67 };
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int
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main(void)
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{
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/* pointers into the byte order array */
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int *intp = (int *)byte;
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#if defined(DEBUG)
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short *shortp = (short *)byte;
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long *longp = (long *)byte;
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printf("byte: %02x %02x %02x %02x %02x %02x %02x %02x\n",
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byte[0], byte[1], byte[2], byte[3],
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byte[4], byte[5], byte[6], byte[7]);
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printf("short: %04x %04x %04x %04x\n",
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shortp[0], shortp[1], shortp[2], shortp[3]);
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printf("int: %08x %08x\n",
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intp[0], intp[1]);
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printf("long: %08x %08x\n",
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longp[0], longp[1]);
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#endif
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/* Print the standard <machine/endian.h> defines */
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printf("#define BIG_ENDIAN\t4321\n");
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printf("#define LITTLE_ENDIAN\t1234\n");
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/* Determine byte order */
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if (intp[0] == 0x12364859) {
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/* Most Significant Byte first */
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printf("#define CALC_BYTE_ORDER\tBIG_ENDIAN\n");
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} else if (intp[0] == 0x59483612) {
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/* Least Significant Byte first */
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printf("#define CALC_BYTE_ORDER\tLITTLE_ENDIAN\n");
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} else {
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fprintf(stderr,
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"Unknown int Byte Order, set CALC_BYTE_ORDER in Makefile\n");
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exit(1);
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}
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/* exit(0); */
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return 0;
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}
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