用函数判断系统是Big Endian还是Little Endian

#include <stdio.h>;

union {
long Long;
char Char[sizeof(long)];
}u;

int main(void)
{
u.Long = 1;

if (u.Char[0] == 1)
printf("addressing is right-to-left/n");
else if (u.Char[sizeof(long) - 1] == 1)
printf("addressing is left-to-right/n");
else
printf("addressing is strange/n");

return 0;
}