GETNAMEINFO(3)         FreeBSD Library Functions Manual         GETNAMEINFO(3)

NNAAMMEE
    ggeettnnaammeeiinnffoo -- address-to-name translation in protocol-independent manner

SSYYNNOOPPSSIISS
    ##iinncclluuddee <<ssyyss//ssoocckkeett..hh>>
    ##iinncclluuddee <<nneettddbb..hh>>

    _i_n_t
    ggeettnnaammeeiinnffoo(_c_o_n_s_t _s_t_r_u_c_t _s_o_c_k_a_d_d_r _*_s_a, _s_o_c_k_l_e_n___t _s_a_l_e_n, _c_h_a_r _*_h_o_s_t,
        _s_i_z_e___t _h_o_s_t_l_e_n, _c_h_a_r _*_s_e_r_v, _s_i_z_e___t _s_e_r_v_l_e_n, _i_n_t _f_l_a_g_s);

DDEESSCCRRIIPPTTIIOONN
    The ggeettnnaammeeiinnffoo() function is defined for protocol-independent address-
    to-nodename translation.  It performs functionality of gethostbyaddr(3)
    and getservbyport(3) in more sophisticated manner.

    The _s_a arguement is a pointer to a generic socket address structure of
    size _s_a_l_e_n.  The arguements _h_o_s_t and _s_e_r_v are pointers to buffers to hold
    the return values.  Their sizes are specified by _h_o_s_t_l_e_n and _s_e_r_v_l_e_n
    repectively.  Either _h_o_s_t or _s_e_r_v may be NULL if the hostname  or service
    name is not required.

    The _f_l_a_g_s arguement modifies the behaviour of ggeettnnaammeeiinnffoo() as follows:

    If NI_NOFQDN is set only the unqualified hostname is returned for local
    fully qualified names.

    If NI_NUMERICHOST is set then the numeric form of the hostname is
    returned.

    If NI_NAMEREQD is set, then a error is returned if the hostname cannot be
    looked up.

    If NI_NUMERICSERV is set then the service is returned in numeric form.

    If NI_DGRAM is set then the service is UDP based rather than TCP based.

SSEEEE AALLSSOO
    getaddrinfo(3), gethostbyaddr(3), getservbyport(3), hosts(5),
    services(5), hostname(7),

    R. Gilligan, S.  Thomson, J. Bound, and W. Stevens, ``Basic Socket Inter-
    face Extensions for IPv6,'' RFC2133, April 1997.

SSTTAANNDDAARRDDSS
    The ggeettaaddddrriinnffoo() function is defined IEEE POSIX 1003.1g draft specifica-
    tion, and documented in ``Basic Socket Interface Extensions for IPv6''
    (RFC2133).

                              January 11, 1999