将以太网地址转换为可读形式？

struct ethernet_header
{
    u_char ether_dhost[ ETHER_ADDR_LEN];

    u_char ether_shost[ETHER_ADDR_LEN];

    u_short ether_type;
};

for(i = 0;i <6; i++)
  printf("dest ether:%x",ethernet->ether_dhost);

如何以正确可读的形式打印以太网地址，并在每个字节后添加空格？我得到的 o/p 是十六进制的。这里的Ethernet是指向该结构体的指针ethernet_header.

怎么样：

printf("%02x:%02x:%02x:%02x:%02x:%02x",
    (unsigned)ethernet->ether_dhost[0],
    (unsigned)ethernet->ether_dhost[1],
    (unsigned)ethernet->ether_dhost[2],
    (unsigned)ethernet->ether_dhost[3],
    (unsigned)ethernet->ether_dhost[4],
    (unsigned)ethernet->ether_dhost[5]);