ARES_GETHOSTBYNAME(3)  FreeBSD Library Functions Manual  ARES_GETHOSTBYNAME(3)

NAME
       ares_gethostbyname - Initiate a host query by name

SYNOPSIS
       #include <ares.h>

       typedef void (*ares_host_callback)(void *arg, int status,
       int timeouts, struct hostent *hostent)

       void ares_gethostbyname(ares_channel channel, const char *name,
            int family, ares_host_callback callback, void *arg)

DESCRIPTION
       The ares_gethostbyname function initiates a host query by name on the
       name service channel identified by channel.  The parameter name gives
       the hostname as a NUL-terminated C string, and family gives the desired
       type of address for the resulting host entry.  When the query is
       complete or has failed, the ares library will invoke callback.
       Completion or failure of the query may happen immediately, or may
       happen during a later call to _process&section=3">ares_process(3), _destroy&section=3">ares_destroy(3) or
       _cancel&section=3">ares_cancel(3).

       The callback argument arg is copied from the ares_gethostbyname
       argument arg.  The callback argument status indicates whether the query
       succeeded and, if not, how it failed.  It may have any of the following
       values:

       ARES_SUCCESS       The host lookup completed successfully.

       ARES_ENOTIMP       The ares library does not know how to find addresses
                          of type family.

       ARES_EBADNAME      The hostname name is composed entirely of numbers
                          and periods, but is not a valid representation of an
                          Internet address.

       ARES_ENODATA       There was no data returned to extract a result from.

       ARES_ENOTFOUND     The name name was not found.

       ARES_ENOMEM        Memory was exhausted.

       ARES_ECANCELLED    The query was cancelled.

       ARES_EDESTRUCTION  The name service channel channel is being destroyed;
                          the query will not be completed.

       The callback argument timeouts reports how many times a query timed out
       during the execution of the given request.

       On successful completion of the query, the callback argument hostent
       points to a struct hostent containing the name of the host returned by
       the query.  The callback need not and should not attempt to free the
       memory pointed to by hostent; the ares library will free it when the
       callback returns.  If the query did not complete successfully, hostent
       will be NULL.

SEE ALSO
       ares_process(3), ares_gethostbyaddr(3)

AUTHOR
       Greg Hudson, MIT Information Systems
       Copyright 1998 by the Massachusetts Institute of Technology.

                                 25 July 1998            ARES_GETHOSTBYNAME(3)