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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  buf-
       fer,  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).
       +----------------------------------+---------------+-----------+
       |Interface                         | Attribute     | Value     |
       +----------------------------------+---------------+-----------+
       |ether_aton(), ether_ntoa()        | Thread safety | MT-Unsafe |
       +----------------------------------+---------------+-----------+
       |ether_ntohost(), ether_hostton(), | Thread safety | MT-Safe   |
       |ether_line(), ether_ntoa_r(),     |               |           |
       |ether_aton_r()                    |               |           |
       +----------------------------------+---------------+-----------+
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 4.15 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)