WCTOMB(3)                  POSIX Programmer's Manual                 WCTOMB(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
       wctomb -- convert a wide-character code to a character

SSYYNNOOPPSSIISS
       #include <stdlib.h>

       int wctomb(char *_s, wchar_t _w_c_h_a_r);

DDEESSCCRRIIPPTTIIOONN
       The functionality described on this reference page is aligned with the
       ISO C standard. Any conflict between the requirements described here
       and the ISO C standard is unintentional. This volume of POSIX.1-2017
       defers to the ISO C standard.

       The _w_c_t_o_m_b() function shall determine the number of bytes needed to
       represent the character corresponding to the wide-character code whose
       value is _w_c_h_a_r (including any change in the shift state). It shall
       store the character representation (possibly multiple bytes and any
       special bytes to change shift state) in the array object pointed to by
       _s (if _s is not a null pointer). At most {MB_CUR_MAX} bytes shall be
       stored. If _w_c_h_a_r is 0, a null byte shall be stored, preceded by any
       shift sequence needed to restore the initial shift state, and _w_c_t_o_m_b()
       shall be left in the initial shift state.

       The behavior of this function is affected by the _L_C___C_T_Y_P_E category of
       the current locale. For a state-dependent encoding, this function shall
       be placed into its initial state by a call for which its character
       pointer argument, _s, is a null pointer. Subsequent calls with _s as
       other than a null pointer shall cause the internal state of the
       function to be altered as necessary. A call with _s as a null pointer
       shall cause this function to return a non-zero value if encodings have
       state dependency, and 0 otherwise. Changing the _L_C___C_T_Y_P_E category
       causes the shift state of this function to be unspecified.

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

       The implementation shall behave as if no function defined in this
       volume of POSIX.1-2017 calls _w_c_t_o_m_b().

RREETTUURRNN VVAALLUUEE
       If _s is a null pointer, _w_c_t_o_m_b() shall return a non-zero or 0 value, if
       character encodings, respectively, do or do not have state-dependent
       encodings. If _s is not a null pointer, _w_c_t_o_m_b() shall return -1 if the
       value of _w_c_h_a_r does not correspond to a valid character, or return the
       number of bytes that constitute the character corresponding to the
       value of _w_c_h_a_r.

       In no case shall the value returned be greater than the value of the
       {MB_CUR_MAX} macro.

EERRRROORRSS
       The _w_c_t_o_m_b() function shall fail if:

       EEIILLSSEEQQ An invalid wide-character code is detected.

       _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
       _m_b_l_e_n(), _m_b_t_o_w_c(), _m_b_s_t_o_w_c_s(), _w_c_s_t_o_m_b_s()

       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                            WCTOMB(3)
