絕大多數的pc的cpu是little-endian
不過這個程序的思路還是讓我感到佩服
當然 也是我太菜
方法1
定義聯合結構體
union endian_un
{
short var;
char bits[sizeof ( short ) ];
};
short 在32位下佔2個字節 int 佔4個字節
然後var=0x0102
這樣字符數組也存上了這個數
看看bits[0]裏存放的是1還是2就可以判斷了
方法2
將short強制轉換爲char
看看char裏是short的高位還是低位就可以判斷了
/***************************************************************************
* Copyright (C) 2008 by root *
判斷cpu類型 big-endian or little-endian
線程模型:posix
gcc 版本 4.1.2 20070925 (Red Hat 4.1.2-33)
***************************************************************************/
#include <stdio.h>
union endian_un
{
short var;
char bits[sizeof ( short ) ];
};
int main ( int argc, char *argv[] )
{
union endian_un flag;
flag.var=0x0102;
if ( sizeof ( short ) ==2 )
{
if ( flag.bits[0]==1&&flag.bits[1]==2 )
{
printf ( "judged by first method big-endian/n" );
}
if ( flag.bits[0]=2&&flag.bits[1]==1 )
{
printf ( "judged by first method little-endian/n" );
}
}
unsigned short f=0x4321;
if ( * ( unsigned char * ) &f==0x21 )
{
printf ( "judged by second method little-endian/n" );
}
if ( * ( unsigned char * ) &f==0x43 )
{
printf ( "judged by second method big-endian/n" );
}
return 1;
}