Files
calc/endian.c
Landon Curt Noll a31078bbec Remove all RCS @(#) lines and RCS strings
Some folks might think: “you still use RCS”?!?  And we will say,
hey, at least we switched from SCCS to RCS back in … I think it was
around 1994 ... at least we are keeping up! :-) :-) :-)

Logs say that SCCS version 18 became RCS version 19 on 1994 March 18.

RCS served us well.  But now it is time to move on.   And so we are
switching to git.

Calc releases produce a lot of file changes.  In the 125 releases
of calc since 1996, when I started managing calc releases, there
have been 15473 file mods!
2017-05-23 01:33:23 -07:00

102 lines
3.1 KiB
C

/*
* endian - determine the byte order of a long on your machine
*
* Copyright (C) 1999-2013 Landon Curt Noll
*
* Calc is open software; you can redistribute it and/or modify it under
* the terms of the version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* Calc 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.
*
* A copy of version 2.1 of the GNU Lesser General Public License is
* distributed with calc under the filename COPYING-LGPL. You should have
* received a copy with calc; if not, write to Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Under source code control: 1993/11/15 04:32:58
* File existed as early as: 1993
*
* chongo <was here> /\oo/\ http://www.isthe.com/chongo/
* Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
*/
/*
* Big Endian: Amdahl, 68k, Pyramid, Mips, Sparc, ...
* Little Endian: Vax, 32k, Spim (Dec Mips), i386, i486, ...
*/
#include <stdio.h>
#include "have_stdlib.h"
#if defined(HAVE_STDLIB_H)
#include <stdlib.h>
#endif
#include "have_unistd.h"
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
/* byte order array */
char byte[8] = { (char)0x12, (char)0x36, (char)0x48, (char)0x59,
(char)0x01, (char)0x23, (char)0x45, (char)0x67 };
int
main(void)
{
/* pointers into the byte order array */
#if defined(DEBUG) || (!defined(BIG_ENDIAN) && !defined(BIG_ENDIAN))
int *intp = (int *)byte;
#endif
#if defined(DEBUG)
short *shortp = (short *)byte;
long *longp = (long *)byte;
printf("byte: %02x %02x %02x %02x %02x %02x %02x %02x\n",
byte[0], byte[1], byte[2], byte[3],
byte[4], byte[5], byte[6], byte[7]);
printf("short: %04x %04x %04x %04x\n",
shortp[0], shortp[1], shortp[2], shortp[3]);
printf("int: %08x %08x\n",
intp[0], intp[1]);
printf("long: %08x %08x\n",
longp[0], longp[1]);
#endif
/* Print the standard <machine/endian.h> defines */
printf("#undef BIG_ENDIAN\n");
printf("#define BIG_ENDIAN\t4321\n");
printf("#undef LITTLE_ENDIAN\n");
printf("#define LITTLE_ENDIAN\t1234\n");
printf("#undef CALC_BYTE_ORDER\n");
#if defined(BIG_ENDIAN)
printf("#define CALC_BYTE_ORDER\tBIG_ENDIAN\n");
#elif defined(LITTLE_ENDIAN)
printf("#define CALC_BYTE_ORDER\tLITTLW_ENDIAN\n");
#else
/* Determine byte order */
if (intp[0] == 0x12364859) {
/* Most Significant Byte first */
printf("#define CALC_BYTE_ORDER\tBIG_ENDIAN\n");
} else if (intp[0] == 0x59483612) {
/* Least Significant Byte first */
printf("#define CALC_BYTE_ORDER\tLITTLE_ENDIAN\n");
} else {
fprintf(stderr, "@=-=@ Fatal build error - cannot @=-=@\n");
fprintf(stderr, "@=-=@ determine byte order. Set @=-=@\n");
fprintf(stderr, "@=-=@ ${CALC_BYTE_ORDER} in the Makefile @=-=@\n");
fprintf(stderr, "@=-=@ to be either -DBIG_ENDIAN or @=-=@\n");
fprintf(stderr, "@=-=@ to be -DLITTLE_ENDIAN @=-=@\n");
exit(1);
}
#endif
/* exit(0); */
return 0;
}