ether_aton, ether_ntoa, ether_ntohost, ether_hostton, ether_line, ether_ntoa_r,
ether_aton_r - Ethernet address manipulation routines
#include <netinet/ether.h>
char *ether_ntoa(const struct ether_addr *addr);
struct ether_addr *ether_aton(const char *asc);
int ether_ntohost(char *hostname, const struct ether_addr *addr);
int ether_hostton(const char *hostname, struct ether_addr *addr);
int ether_line(const char *line, struct ether_addr *addr,
char *hostname);
/* GNU extensions */
char *ether_ntoa_r(const struct ether_addr *addr, char *buf);
struct ether_addr *ether_aton_r(const char *asc,
struct ether_addr *addr);
ether_aton() converts the 48-bit Ethernet host address
asc from
the standard hex-digits-and-colons notation into binary data in network byte
order and returns a pointer to it in a statically allocated buffer, which
subsequent calls will overwrite.
ether_aton() returns NULL if the
address is invalid.
The
ether_ntoa() function converts the Ethernet host address
addr
given in network byte order to a string in standard hex-digits-and-colons
notation, omitting leading zeros. The string is returned in a statically
allocated buffer, which subsequent calls will overwrite.
The
ether_ntohost() function maps an Ethernet address to the
corresponding hostname in
/etc/ethers and returns nonzero if it cannot
be found.
The
ether_hostton() function maps a hostname to the corresponding
Ethernet address in
/etc/ethers and returns nonzero if it cannot be
found.
The
ether_line() function parses a line in
/etc/ethers format
(ethernet address followed by whitespace followed by hostname; '#' introduces
a comment) and returns an address and hostname pair, or nonzero if it cannot
be parsed. The buffer pointed to by
hostname must be sufficiently long,
for example, have the same length as
line.
The functions
ether_ntoa_r() and
ether_aton_r() are reentrant
thread-safe versions of
ether_ntoa() and
ether_aton()
respectively, and do not use static buffers.
The structure
ether_addr is defined in
<net/ethernet.h> as:
struct ether_addr {
uint8_t ether_addr_octet[6];
}
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| ether_aton (), ether_ntoa () |
Thread safety |
MT-Unsafe |
| ether_ntohost (), ether_hostton (), ether_line (), ether_ntoa_r (),
ether_aton_r () |
Thread safety |
MT-Safe |
4.3BSD, SunOS.
In glibc 2.2.5 and earlier, the implementation of
ether_line() is broken.
ethers(5)