byteorder.c

来自「variable concept for embedded systems」· C语言 代码 · 共 51 行

/*
    This programs aim is to verify the byte ordering system on
    on my PC and on ngw100.Source from Unix Network Programming(pg 78)

    Copyright (C) 2009  Iban Lopetegui

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/
/*
To compile
gcc -o byteorder byteorder.c

avr32-linux-gcc -o byteorder.elf byteorder.c

*/

#include <stdio.h>

int main (int argc, char **argv)
{
	union{			/*structure that gathers the same value for the short and the char*/
		short  s;
		char  c[sizeof(short)];
	}un;
	un.s=0x0102;
	if (sizeof(short)==2){
		if ((un.c[0]==1)&&(un.c[1]==2))
				printf("little endian\n");
		else if ((un.c[0]==2)&&(un.c[1]==1))
				printf("big endian\n");
		else printf("unkown\n");
	} else
		printf("size of short is %d\n",sizeof(short));	
	
	return 0;


}