ETHER_ATON(3)
Linux Programmer’s Manual
ETHER_ATON(3)
NAME
ether_aton, ether_ntoa, ether_ntohost, ether_hostton, ether_line, ether_ntoa_r, ether_aton_r − Ethernet
address manipulation routines
SYNOPSIS
#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);
DESCRIPTION
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 sub-
sequent 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 fol-
lowed 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