1ARES_GETHOSTBYADDR(3)      Library Functions Manual      ARES_GETHOSTBYADDR(3)
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NAME

6       ares_gethostbyaddr - Initiate a host query by address
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SYNOPSIS

9       #include <ares.h>
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11       typedef void (*ares_host_callback)(void *arg, int status,
12                                          int timeouts,
13                                          struct hostent *hostent)
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15       void ares_gethostbyaddr(ares_channel channel, const void *addr,
16                               int addrlen, int family,
17                               ares_host_callback callback, void *arg)
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DESCRIPTION

20       The  ares_gethostbyaddr  function  initiates a host query by address on
21       the name service channel identified by channel.   The  parameters  addr
22       and addrlen give the address as a series of bytes, and family gives the
23       type of address.  When the query is complete or has  failed,  the  ares
24       library  will  invoke callback.  Completion or failure of the query may
25       happen  immediately,  or  may   happen   during   a   later   call   to
26       ares_process(3), ares_destroy(3) or ares_cancel(3).
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28       The  callback  argument arg is copied from the ares_gethostbyaddr argu‐
29       ment arg.  The callback argument status  indicates  whether  the  query
30       succeeded and, if not, how it failed.  It may have any of the following
31       values:
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33       ARES_SUCCESS       The host lookup completed successfully.
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35       ARES_ENOTIMP       The ares library does not know how to  look  up  ad‐
36                          dresses of type family.
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38       ARES_ENOTFOUND     The address addr was not found.
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40       ARES_ENOMEM        Memory was exhausted.
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42       ARES_ECANCELLED    The query was cancelled.
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44       ARES_EDESTRUCTION  The name service channel channel is being destroyed;
45                          the query will not be completed.
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47       The callback argument timeouts reports how many times a query timed out
48       during the execution of the given request.
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50       On  successful  completion  of the query, the callback argument hostent
51       points to a struct hostent containing the name of the host returned  by
52       the  query.   The  callback need not and should not attempt to free the
53       memory pointed to by hostent; the ares library will free  it  when  the
54       callback  returns.  If the query did not complete successfully, hostent
55       will be NULL.
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SEE ALSO

58       ares_process(3), ares_gethostbyname(3)
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AUTHOR

61       Greg Hudson, MIT Information Systems
62       Copyright 1998 by the Massachusetts Institute of Technology.
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66                                 24 July 1998            ARES_GETHOSTBYADDR(3)
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