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  subsequent  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  stati-
       cally allocated buffer, which subsequent calls will overwrite.

       The  ether_ntohost()  function  maps  an Ethernet address to the corre-
       sponding hostname in /etc/ethers and returns nonzero if  it  cannot  be
       found.

       The  ether_hostton() function maps a hostname to the corresponding Eth-
       ernet 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 followed 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  suffi-
       ciently 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 buffers.

       The structure ether_addr is defined in <net/ethernet.h> as:

           struct ether_addr {
               uint8_t ether_addr_octet[6]; }

ATTRIBUTES
       For   an   explanation   of   the  terms  used  in  this  section,  see
       attributes(7).

       allbox; lbw33 lb lb l l l.  Interface Attribute Value T{ ether_aton(),
       ether_ntoa() T}   Thread safety  MT-Unsafe T{ ether_ntohost(),
       ether_hostton(), ether_line(), ether_ntoa_r(), ether_aton_r()
       T}   Thread safety   MT-Safe

CONFORMING TO
       4.3BSD, SunOS.

BUGS
       In  glibc 2.2.5 and earlier, the implementation of ether_line() is bro-
       ken.

SEE ALSO
       ethers(5)

COLOPHON
       This page is part of release 4.16 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.



GNU                               2017-09-15                     ETHER_ATON(3)