ENDHOSTENT(3)              POSIX Programmer's Manual             ENDHOSTENT(3)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       endhostent, gethostent, sethostent -- network host database functions

SSYYNNOOPPSSIISS
       #include <netdb.h>

       void endhostent(void);
       struct hostent *gethostent(void);
       void sethostent(int _s_t_a_y_o_p_e_n);

DDEESSCCRRIIPPTTIIOONN
       These functions shall retrieve information about hosts. This
       information is considered to be stored in a database that can be
       accessed sequentially or randomly. The implementation of this database
       is unspecified.

       NNoottee::     In many cases this database is implemented by the Domain Name
                 System, as documented in RFC 1034, RFC 1035, and RFC 1886.

       The _s_e_t_h_o_s_t_e_n_t() function shall open a connection to the database and
       set the next entry for retrieval to the first entry in the database. If
       the _s_t_a_y_o_p_e_n argument is non-zero, the connection shall not be closed
       by a call to _g_e_t_h_o_s_t_e_n_t(), and the implementation may maintain an open
       file descriptor.

       The _g_e_t_h_o_s_t_e_n_t() function shall read the next entry in the database,
       opening and closing a connection to the database as necessary.

       Entries shall be returned in hhoosstteenntt structures.

       The _e_n_d_h_o_s_t_e_n_t() function shall close the connection to the database,
       releasing any open file descriptor.

       These functions need not be thread-safe.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, the _g_e_t_h_o_s_t_e_n_t() function shall return a
       pointer to a hhoosstteenntt structure if the requested entry was found, and a
       null pointer if the end of the database was reached or the requested
       entry was not found.

       The application shall not modify the structure to which the return
       value points, nor any storage areas pointed to by pointers within the
       structure. The returned pointer, and pointers within the structure,
       might be invalidated or the structure or the storage areas might be
       overwritten by a subsequent call to _g_e_t_h_o_s_t_e_n_t().  The returned
       pointer, and pointers within the structure, might also be invalidated
       if the calling thread is terminated.

EERRRROORRSS
       No errors are defined for _e_n_d_h_o_s_t_e_n_t(), _g_e_t_h_o_s_t_e_n_t(), and _s_e_t_h_o_s_t_e_n_t().

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _e_n_d_s_e_r_v_e_n_t()

       The Base Definitions volume of POSIX.1-2017, <<nneettddbb..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                        ENDHOSTENT(3)
