1ETHER_ATON(3)              Linux Programmer's Manual             ETHER_ATON(3)
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NAME

6       ether_aton,   ether_ntoa,   ether_ntohost,  ether_hostton,  ether_line,
7       ether_ntoa_r, ether_aton_r - Ethernet address manipulation routines
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SYNOPSIS

10       #include <netinet/ether.h>
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12       char *ether_ntoa(const struct ether_addr *addr);
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14       struct ether_addr *ether_aton(const char *asc);
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16       int ether_ntohost(char *hostname, const struct ether_addr *addr);
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18       int ether_hostton(const char *hostname, struct ether_addr *addr);
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20       int ether_line(const char *line, struct ether_addr *addr,
21                      char *hostname);
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23       /* GNU extensions */
24       char *ether_ntoa_r(const struct ether_addr *addr, char *buf);
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26       struct ether_addr *ether_aton_r(const char *asc,
27                                       struct ether_addr *addr);
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DESCRIPTION

30       ether_aton() converts the 48-bit Ethernet host  address  asc  from  the
31       standard  hex-digits-and-colons  notation  into  binary data in network
32       byte order and returns a pointer to it in a statically  allocated  buf‐
33       fer,  which subsequent calls will overwrite.  ether_aton() returns NULL
34       if the address is invalid.
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36       The ether_ntoa() function converts the Ethernet host address addr given
37       in  network  byte  order  to a string in standard hex-digits-and-colons
38       notation, omitting leading zeros.  The string is returned in  a  stati‐
39       cally allocated buffer, which subsequent calls will overwrite.
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41       The  ether_ntohost()  function  maps  an Ethernet address to the corre‐
42       sponding hostname in /etc/ethers and returns non-zero if it  cannot  be
43       found.
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45       The  ether_hostton() function maps a hostname to the corresponding Eth‐
46       ernet address in /etc/ethers and  returns  non-zero  if  it  cannot  be
47       found.
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49       The ether_line() function parses a line in /etc/ethers format (ethernet
50       address followed by whitespace followed by hostname; '#'  introduces  a
51       comment)  and  returns  an address and hostname pair, or non-zero if it
52       cannot be parsed.  The buffer pointed to by  hostname  must  be  suffi‐
53       ciently long, for example, have the same length as line.
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55       The  functions  ether_ntoa_r() and ether_aton_r() are reentrant thread-
56       safe versions of ether_ntoa() and ether_aton() respectively, and do not
57       use static buffers.
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59       The structure ether_addr is defined in <net/ethernet.h> as:
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61           struct ether_addr {
62               uint8_t ether_addr_octet[6];
63           }
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CONFORMING TO

66       4.3BSD, SunOS.
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BUGS

69       The glibc 2.2.5 implementation of ether_line() is broken.
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SEE ALSO

72       ethers(5)
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COLOPHON

75       This  page  is  part of release 3.22 of the Linux man-pages project.  A
76       description of the project, and information about reporting  bugs,  can
77       be found at http://www.kernel.org/doc/man-pages/.
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81GNU                               2002-07-20                     ETHER_ATON(3)