ethers(3)ethers(3)NAME
ethers, ether_ntoa, ether_aton, ether_ntohost, ether_hostton,
ether_line - Ethernet address mapping operations
SYNOPSIS
#include <sys/types.h> #include <sys/socket.h> #include <net/if.h>
#include <netinet/in.h> #include <netinet/if_ether.h>
char *ether_ntoa(
struct ether_addr *e ); struct ether_addr *ether_aton(
char *s ); ether_ntohost(
char *hostname,
struct ether_addr *e ); ether_hostton(
char *hostname,
struct ether_addr *e ); ether_line(
char *l,
struct ether_addr *e,
char *hostname );
Arguments
The ether_addr structure is defined in <netinet/if_ether.h>
DESCRIPTION
These routines are useful for mapping 48-bit Ethernet numbers to their
ASCII representations or their corresponding host names, and vice
versa. The mapping is obtained from the /etc/ethers database; see
ethers(4).
The function ether_ntoa() converts a 48-bit Ethernet number pointed to
by e to its standard ACSII representation; it returns a pointer to the
ASCII string. The representation is of the form: x : x : x : x : x : x
Where x is a hexadecimal number between 0 and ff.
The function ether_aton() converts an ASCII string in the standard rep‐
resentation back to a 48-bit Ethernet number; the function returns NULL
if the string cannot be scanned successfully.
The function ether_ntohost() maps an Ethernet number (pointed to by e)
to its associated hostname. The string pointed to by hostname must be
long enough to hold the hostname and a NULL character. The function
returns zero upon success and nonzero upon failure.
Inversely, the function ether_hostton() maps a hostname string to its
corresponding Ethernet number; the function modifies the Ethernet num‐
ber pointed to by e. The function also returns zero upon success and
nonzero upon failure.
The function ether_line() scans a line (pointed to by l) and sets the
hostname and the Ethernet number (pointed to by e). The string pointed
to by hostname must be long enough to hold the hostname and a NULL
character. The function returns zero upon success and nonzero upon
failure. The format of the scanned line is described by ethers(4).
FILES
Database that maps Ethernet addresses to hostnames
SEE ALSO
Commands: rarpd(8)
Files: packetfilter(7), ethers(4)ethers(3)