ethers(3N)              NETWORK FUNCTIONS              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 correspond-
     ing 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 host-
     name  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 suc-
     cess and non-zero upon failure.  The  function  etherline()



                       Last change: TCP/IP                      1

ethers(3N)              NETWORK FUNCTIONS              ethers(3N)



     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(4).

FILES
     /etc/ethers

SEE ALSO
     ethers(4)











































                       Last change: TCP/IP                      2