TTYNAME(3)                 POSIX Programmer's Manual                TTYNAME(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
       ttyname, ttyname_r -- find the pathname of a terminal

SSYYNNOOPPSSIISS
       #include <unistd.h>

       char *ttyname(int _f_i_l_d_e_s);
       int ttyname_r(int _f_i_l_d_e_s, char *_n_a_m_e, size_t _n_a_m_e_s_i_z_e);

DDEESSCCRRIIPPTTIIOONN
       The _t_t_y_n_a_m_e() function shall return a pointer to a string containing a
       null-terminated pathname of the terminal associated with file
       descriptor _f_i_l_d_e_s.  The application shall not modify the string
       returned. The returned pointer might be invalidated or the string
       content might be overwritten by a subsequent call to _t_t_y_n_a_m_e().  The
       returned pointer and the string content might also be invalidated if
       the calling thread is terminated.

       The _t_t_y_n_a_m_e() function need not be thread-safe.

       The _t_t_y_n_a_m_e___r() function shall store the null-terminated pathname of
       the terminal associated with the file descriptor _f_i_l_d_e_s in the
       character array referenced by _n_a_m_e.  The array is _n_a_m_e_s_i_z_e characters
       long and should have space for the name and the terminating null
       character. The maximum length of the terminal name shall be
       {TTY_NAME_MAX}.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, _t_t_y_n_a_m_e() shall return a pointer to a
       string. Otherwise, a null pointer shall be returned and _e_r_r_n_o set to
       indicate the error.

       If successful, the _t_t_y_n_a_m_e___r() function shall return zero. Otherwise,
       an error number shall be returned to indicate the error.

EERRRROORRSS
       The _t_t_y_n_a_m_e() function may fail if:

       EEBBAADDFF  The _f_i_l_d_e_s argument is not a valid file descriptor.

       EENNOOTTTTYY The file associated with the _f_i_l_d_e_s argument is not a terminal.

       The _t_t_y_n_a_m_e___r() function may fail if:

       EEBBAADDFF  The _f_i_l_d_e_s argument is not a valid file descriptor.

       EENNOOTTTTYY The file associated with the _f_i_l_d_e_s argument is not a terminal.

       EERRAANNGGEE The value of _n_a_m_e_s_i_z_e is smaller than the length of the string
              to be returned including the terminating null character.

       _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
       The term ``terminal'' is used instead of the historical term ``terminal
       device'' in order to avoid a reference to an undefined term.

       The thread-safe version places the terminal name in a user-supplied
       buffer and returns a non-zero value if it fails. The non-thread-safe
       version may return the name in a static data area that may be
       overwritten by each call.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       The Base Definitions volume of POSIX.1-2017, <<uunniissttdd..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                           TTYNAME(3)
