EUI64(3)

🦋 EUI64(3) — Library Functions Manual, bestie edition 🦋

okay so this is the EUI64(3) page for the IEEE EUI-64 conversion and lookup girlies — let's get into it 💅

✨ NAME ✨

• eui64, eui64_aton, eui64_ntoa, eui64_ntohost, eui64_hostton — IEEE EUI-64 conversion and lookup routines, no cap 🎀

📚 LIBRARY 📚

Standard C Library (libc, -lc) — she's iconic, she's everywhere 💖

💻 SYNOPSIS 💻

#include <sys/types.h>
#include <sys/eui64.h>

int
eui64_aton(const char *a, struct eui64 *e);

int
eui64_ntoa(const struct eui64 *id, char *a, size_t len);

int
eui64_ntohost(char *hostname, size_t len, const struct eui64 *id);

int
eui64_hostton(const char *hostname, struct eui64 *id);

🌸 DESCRIPTION 🌸

okay bestie, these functions operate on IEEE EUI-64s using an eui64 structure, which is defined in the header file <sys/eui64.h>:

/*
 * The number of bytes in an EUI-64.
 */
#define EUI64_LEN               8

/*
 * Structure of an IEEE EUI-64.
 */
struct  eui64 {
        u_char octet[EUI64_LEN];
};

The eui64_aton() function converts an ASCII representation of an EUI-64 into an eui64 structure. Likewise, eui64_ntoa() converts an EUI-64 specified as an eui64 structure into an ASCII string — literal glow-up in both directions ✨

The eui64_ntohost() and eui64_hostton() functions map EUI-64s to their corresponding hostnames as specified in the /etc/eui64 database. The eui64_ntohost() function converts from EUI-64 to hostname, and eui64_hostton() converts from hostname to EUI-64. Matching besties, but make it lookup 🫶

🔁 RETURN VALUES 🔁

On success, eui64_ntoa() returns a pointer to a string containing an ASCII representation of an EUI-64. If it is unable to convert the supplied eui64 structure, it returns a NULL pointer. Likewise, eui64_aton() returns a pointer to an eui64 structure on success and a NULL pointer on failure.

The eui64_ntohost() and eui64_hostton() functions both return zero on success or non-zero if they were unable to find a match in the /etc/eui64 database. Zero is the slay outcome, non-zero is the "did not find it, bestie" outcome 💀

📝 NOTES 📝

bestie, the user must ensure that the hostname strings passed to the eui64_ntohost() and eui64_hostton() functions are large enough to contain the returned hostnames. No tiny buffers, okay? 😭

🌈 NIS INTERACTION 🌈

If the /etc/eui64 contains a line with a single ‘+’ in it, the eui64_ntohost() and eui64_hostton() functions will attempt to consult the NIS eui64.byname and eui64.byid maps in addition to the data in the /etc/eui64 file. NIS said "I'm also invited to this party" 💅

👀 SEE ALSO 👀

• firewire(4)
• eui64(5)
• yp(8)

📜 HISTORY 📜

These functions first appears in FreeBSD 5.3. They are derived from the ethers(3) family of functions. yes, that's the exact wording — we keep the lore fr fr 🎀

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💖 cute sign-off: from Debian, dated March 4, 2004, and this is EUI64(3) — mwah! 🎀