c语言判断系统大小端

#include<stdio.h>
bool IsLittle()
{
union
{
char a;
short b;

}ua;
ua.b = 0x0001;
return ua.a == 0x01;

}
int main()
{
if(IsLittle())
{
printf(“小端\n”);

}
else
{
	printf("大端\n");
}
return 0;

}