UNLOCKPT(3)                POSIX Programmer's Manual               UNLOCKPT(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
       unlockpt -- unlock a pseudo-terminal master/slave pair

SSYYNNOOPPSSIISS
       #include <stdlib.h>

       int unlockpt(int _f_i_l_d_e_s);

DDEESSCCRRIIPPTTIIOONN
       The _u_n_l_o_c_k_p_t() function shall unlock the slave pseudo-terminal device
       associated with the master to which _f_i_l_d_e_s refers.

       Conforming applications shall ensure that they call _u_n_l_o_c_k_p_t() before
       opening the slave side of a pseudo-terminal device.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, _u_n_l_o_c_k_p_t() shall return 0. Otherwise, it
       shall return -1 and set _e_r_r_n_o to indicate the error.

EERRRROORRSS
       The _u_n_l_o_c_k_p_t() function may fail if:

       EEBBAADDFF  The _f_i_l_d_e_s argument is not a file descriptor open for writing.

       EEIINNVVAALL The _f_i_l_d_e_s argument is not associated with a master pseudo-
              terminal device.

       _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
       See the RATIONALE section for _p_o_s_i_x___o_p_e_n_p_t().

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _g_r_a_n_t_p_t(), _o_p_e_n(), _p_o_s_i_x___o_p_e_n_p_t(), _p_t_s_n_a_m_e()

       The Base Definitions volume of POSIX.1-2017, <<ssttddlliibb..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                          UNLOCKPT(3)
