ethers(3n)
Name
ethers, ether_ntoa, ether_aton, ether_ntohost, ether_hostton, ether_line − Ethernet address mapping operations
Syntax
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
char *
ether_ntoa(e)
struct ether_addr *e;
struct ether_addr *
ether_aton(s)
char *s;
ether_ntohost(hostname, e)
char *hostname;
struct ether_addr *e;
ether_hostton(hostname, e)
char *hostname;
struct ether_addr *e;
ether_line(l, e, hostname)
char *l;
struct ether_addr *e;
char *hostname;
Arguments
The ether_addr structure is defined as:
struct ether_addr {
u_char ether_addr_octet[6];
};
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(.).
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 representation 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 non-zero upon failure. Inversely, the function ether_hostton() maps a hostname string to its corresponding Ethernet number; the function modifies the Ethernet number pointed to by e. The function also returns zero upon success and non-zero 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 non-zero upon failure. The format of the scanned line is described by ethers(.).
Files
/etc/ethers