1HESIOD(3) HESIOD(3) 2 3 4 5NNAAMMEE 6 hesiod, hesiod_init, hesiod_resolve, hesiod_free_list, hesiod_to_bind, 7 hesiod_end - Hesiod name server interface library 8 9SSYYNNOOPPSSIISS 10 ##iinncclluuddee <<hheessiioodd..hh>> 11 12 iinntt hheessiioodd__iinniitt((vvooiidd ****_c_o_n_t_e_x_t)) 13 cchhaarr ****hheessiioodd__rreessoollvvee((vvooiidd **_c_o_n_t_e_x_t,, ccoonnsstt cchhaarr **_n_a_m_e,, 14 ccoonnsstt cchhaarr **_t_y_p_e)) 15 vvooiidd hheessiioodd__ffrreeee__lliisstt((vvooiidd **_c_o_n_t_e_x_t,, cchhaarr ****_l_i_s_t));; 16 cchhaarr **hheessiioodd__ttoo__bbiinndd((vvooiidd **_c_o_n_t_e_x_t,, ccoonnsstt cchhaarr **_n_a_m_e,, 17 ccoonnsstt cchhaarr **_t_y_p_e)) 18 vvooiidd hheessiioodd__eenndd((vvooiidd **_c_o_n_t_e_x_t)) 19 20DDEESSCCRRIIPPTTIIOONN 21 This family of functions allows you to perform lookups of Hesiod infor‐ 22 mation, which is stored as text records in the Domain Name Service. To 23 perform lookups, you must first initialize a _c_o_n_t_e_x_t, an opaque object 24 which stores information used internally by the library between calls. 25 _h_e_s_i_o_d___i_n_i_t initializes a context, storing a pointer to the context in 26 the location pointed to by the _c_o_n_t_e_x_t argument. _h_e_s_i_o_d___e_n_d frees the 27 resources used by a context. 28 29 _h_e_s_i_o_d___r_e_s_o_l_v_e is the primary interface to the library. If successful, 30 it returns a list of one or more strings giving the records matching 31 _n_a_m_e and _t_y_p_e. The last element of the list is followed by a NULL 32 pointer. It is the caller’s responsibility to call _h_e_s_i_o_d___f_r_e_e___l_i_s_t to 33 free the resources used by the returned list. 34 35 _h_e_s_i_o_d___t_o___b_i_n_d converts _n_a_m_e and _t_y_p_e into the DNS name used by _h_e_s_‐ 36 _i_o_d___r_e_s_o_l_v_e. It is the caller’s responsibility to free the returned 37 string using _f_r_e_e. 38 39RREETTUURRNN VVAALLUUEESS 40 If successful, _h_e_s_i_o_d___i_n_i_t returns 0; otherwise it returns -1 and sets 41 _e_r_r_n_o to indicate the error. On failure, _h_e_s_i_o_d___r_e_s_o_l_v_e and _h_e_s_‐ 42 _i_o_d___t_o___b_i_n_d return NULL and set the global variable _e_r_r_n_o to indicate 43 the error. 44 45EENNVVIIRROONNMMEENNTT 46 If the environment variable HHEESS__DDOOMMAAIINN is set, it will override the 47 domain in the Hesiod configuration file. If the environment variable 48 HHEESSIIOODD__CCOONNFFIIGG is set, it specifies the location of the Hesiod configu‐ 49 ration file. 50 51SSEEEE AALLSSOO 52 ‘Hesiod - Project Athena Technical Plan -- Name Service’ 53 54EERRRROORRSS 55 Hesiod calls may fail because of: 56 57 ENOMEM Insufficient memory was available to carry out the requested 58 operation. 59 60 ENOEXEC 61 _h_e_s_i_o_d___i_n_i_t failed because the Hesiod configuration file was 62 invalid. 63 64 ECONNREFUSED 65 _h_e_s_i_o_d___r_e_s_o_l_v_e failed because no name server could be contacted 66 to answer the query. 67 68 EMSGSIZE 69 _h_e_s_i_o_d___r_e_s_o_l_v_e failed because the query or response was too big 70 to fit into the packet buffers. 71 72 ENOENT _h_e_s_i_o_d___r_e_s_o_l_v_e failed because the name server had no text 73 records matching _n_a_m_e and _t_y_p_e, or _h_e_s_i_o_d___t_o___b_i_n_d failed because 74 the _n_a_m_e argument had a domain extension which could not be 75 resolved with type ‘‘rhs-extension’’ in the local Hesiod domain. 76 77AAUUTTHHOORR 78 Steve Dyer, IBM/Project Athena 79 Greg Hudson, MIT Team Athena 80 Copyright 1987, 1988, 1995, 1996 by the Massachusetts Institute of 81 Technology. 82 83BBUUGGSS 84 The strings corresponding to the _e_r_r_n_o values set by the Hesiod func‐ 85 tions are not particularly indicative of what went wrong, especially 86 for _E_N_O_E_X_E_C and _E_N_O_E_N_T. 87 88 89 90 30 November 1996 HESIOD(3) 91