MAC地址：pad missing left Zeros [英] MAC address:pad missing left Zeros

问题描述

例如，我有一个MAC地址的值为0：22：3f：a：5d：16，我如何将其转换为人类可读的格式，如00：22：3f：0a：5d ：16？
我的mac地址缺少前导零，因为我使用

For example i have a MAC address that has a value of "0:22:3f:a:5d:16", how do i convert this to a human readable format like "00:22:3f:0a:5d:16"? My mac Address has missing leading zeros because i use

string asd = ether_ntoa ((struct ether_addr *)p->add2);//p->add2 is a unsigned char[6]

ether_nota removed前导零，我不知道是否有其他方法来存储一个正确的MAC地址作为字符串。

ether_nota removes the leading zeros,i don't know if there are other ways to store a proper MAC addresses as a string.

推荐答案

实现导致它打印没有零填充只是一个 printf 他们使用％x 而不是％02x 。 struct ether_addr 格式为

The implementation that causes it to print without zero padding is just a printf where they use %x instead of %02x. The struct ether_addr format is documented in the man page, and therefore its internals are not private.

The structure ether_addr is defined in <net/ethernet.h> as:

struct ether_addr {
    uint8_t ether_addr_octet[6];
}

所以说，我会实现自己的版本。 rz 表示可重入和零填充。

So that being said, I'd implement my own version. rz means reentrant and zero padded here.

char *ether_ntoa_rz(const struct ether_addr *addr, char *buf)
{
    sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x",
            addr->ether_addr_octet[0], addr->ether_addr_octet[1],
            addr->ether_addr_octet[2], addr->ether_addr_octet[3],
            addr->ether_addr_octet[4], addr->ether_addr_octet[5]);
    return buf;
}

非可重入版本只有一个静态缓冲区并调用可重入的。

The non-reentrant version would just have a static buffer and call the reentrant one.

char *ether_ntoa_z(const struct ether_addr *addr)
{
    static char buf[18];    /* 12 digits + 5 colons + null terminator */
    return ether_ntoa_rz(addr, buf);
}

如果要查看glibc中函数的实现，如果您搜索，请查找。

If you want to look at the implementation of the function in glibc, you can find it if you search.

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