eui64_aton3
Ieee eui-64 conversion and lookup routines
Part of eui64(3).
Usage
int
int
int
int
Library
Standard C Library (libc, -lc)
Overview
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.
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.
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.
Notes
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.
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.
History
- FreeBSD 16.0-CURRENT (2026-10-27) to FreeBSD 13.3-RELEASE: the text shown here
- FreeBSD 13.2-RELEASE to FreeBSD 13.0-RELEASE
- FreeBSD 12.4-RELEASE
- FreeBSD 12.3-RELEASE
- FreeBSD 12.2-RELEASE
- FreeBSD 12.1-RELEASE
- FreeBSD 12.0-RELEASE
- FreeBSD 11.4-RELEASE
- FreeBSD 11.3-RELEASE
- FreeBSD 11.2-RELEASE
- FreeBSD 11.1-RELEASE
- FreeBSD 11.0-RELEASE
- FreeBSD 10.4-RELEASE
- FreeBSD 10.3-RELEASE
- FreeBSD 10.2-RELEASE
- FreeBSD 10.1-RELEASE
- FreeBSD 10.0-RELEASE
- FreeBSD 9.3-RELEASE
- FreeBSD 9.2-RELEASE
- FreeBSD 9.1-RELEASE
- FreeBSD 9.0-RELEASE
- FreeBSD 8.4-RELEASE
- FreeBSD 8.3-RELEASE
- FreeBSD 8.2-RELEASE
- FreeBSD 8.1-RELEASE
- FreeBSD 8.0-RELEASE
- FreeBSD 7.4-RELEASE
- FreeBSD 7.3-RELEASE
- FreeBSD 7.2-RELEASE
- FreeBSD 7.1-RELEASE
- FreeBSD 7.0-RELEASE
- FreeBSD 6.4-RELEASE
- FreeBSD 6.3-RELEASE to FreeBSD 6.0-RELEASE
- FreeBSD 5.5-RELEASE to FreeBSD 5.3-RELEASE
- FreeBSD 4.11-RELEASE