ENDSERVENT(3)              POSIX Programmer's Manual             ENDSERVENT(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
       endservent, getservbyname, getservbyport, getservent, setservent --
       network services database functions

SSYYNNOOPPSSIISS
       #include <netdb.h>

       void endservent(void);
       struct servent *getservbyname(const char *_n_a_m_e, const char *_p_r_o_t_o);
       struct servent *getservbyport(int _p_o_r_t, const char *_p_r_o_t_o);
       struct servent *getservent(void);
       void setservent(int _s_t_a_y_o_p_e_n);

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

       The _s_e_t_s_e_r_v_e_n_t() function shall open a connection to the database, and
       set the next entry to the first entry. If the _s_t_a_y_o_p_e_n argument is non-
       zero, the _n_e_t database shall not be closed after each call to the
       _g_e_t_s_e_r_v_e_n_t() function (either directly, or indirectly through one of
       the other _g_e_t_s_e_r_v_*() functions), and the implementation may maintain an
       open file descriptor for the database.

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

       The _g_e_t_s_e_r_v_b_y_n_a_m_e() function shall search the database from the
       beginning and find the first entry for which the service name specified
       by _n_a_m_e matches the _s___n_a_m_e member and the protocol name specified by
       _p_r_o_t_o matches the _s___p_r_o_t_o member, opening and closing a connection to
       the database as necessary.  If _p_r_o_t_o is a null pointer, any value of
       the _s___p_r_o_t_o member shall be matched.

       The _g_e_t_s_e_r_v_b_y_p_o_r_t() function shall search the database from the
       beginning and find the first entry for which the port specified by _p_o_r_t
       matches the _s___p_o_r_t member and the protocol name specified by _p_r_o_t_o
       matches the _s___p_r_o_t_o member, opening and closing a connection to the
       database as necessary.  If _p_r_o_t_o is a null pointer, any value of the
       _s___p_r_o_t_o member shall be matched. The _p_o_r_t argument shall be a value
       obtained by converting a uuiinntt1166__tt in network byte order to iinntt.

       The _g_e_t_s_e_r_v_b_y_n_a_m_e(), _g_e_t_s_e_r_v_b_y_p_o_r_t(), and _g_e_t_s_e_r_v_e_n_t() functions shall
       each return a pointer to a sseerrvveenntt structure, the members of which
       shall contain the fields of an entry in the network services database.

       The _e_n_d_s_e_r_v_e_n_t() function shall close the database, releasing any open
       file descriptor.

       These functions need not be thread-safe.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, _g_e_t_s_e_r_v_b_y_n_a_m_e(), _g_e_t_s_e_r_v_b_y_p_o_r_t(), and
       _g_e_t_s_e_r_v_e_n_t() return a pointer to a sseerrvveenntt 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.  Otherwise, a null
       pointer is returned.

       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_s_e_r_v_b_y_n_a_m_e(), _g_e_t_s_e_r_v_b_y_p_o_r_t(),
       or _g_e_t_s_e_r_v_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.

       _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
       The _p_o_r_t argument of _g_e_t_s_e_r_v_b_y_p_o_r_t() need not be compatible with the
       port values of all address families.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _e_n_d_h_o_s_t_e_n_t(), _e_n_d_p_r_o_t_o_e_n_t(), _h_t_o_n_l(), _i_n_e_t___a_d_d_r()

       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                        ENDSERVENT(3)
