ethers(3N)                       (TCP/IP)                        ethers(3N)


   NAME
         ethers - 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 *
              etherntoa(e)
                   struct etheraddr *e;

              struct etheraddr *
              etheraton(s)
                   char *s;
              etherntohost(hostname, e)
                   char *hostname;
                   struct etheraddr *e;
              etherhostton(hostname, e)
                   char *hostname;
                   struct etheraddr *e;
              etherline(l, e, hostname)
                   char *l;
                   struct etheraddr *e;
                   char *hostname;

   DESCRIPTION
         These routines are useful for mapping 48 bit Ethernet numbers to
         their ASCII representations or their corresponding host names, and
         vice versa.

         The function etherntoa() converts a 48 bit Ethernet number pointed
         to by e to its standard ASCII 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
         etheraton() 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 etherntohost() 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 etherhostton() 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 etherline() scans a line
         (pointed to by l) and sets the hostname and the Ethernet number
         (pointed to by e).  The


   8/91                                                                 Page 1

   ethers(3N)                       (TCP/IP)                        ethers(3N)


         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(4).

   FILES
         /etc/ethers

   SEE ALSO
         ethers(4)











































   Page 2                                                                 8/91