网络编程DAY 1

 字节序判断：

#include 

union test
{
    char ch;// 0x78
    int num;// 0x12 34 56 78
};

int main(int argc, char const *argv[])
{
    union test t;
    t.num = 0x12345678;
    if(0x78 == t.ch)
    {
        printf("small endian.\n");
    }
    else
    {
        printf("big endian.\n");
    }
    return 0;
}