BTOWC(3)                   POSIX Programmer's Manual                  BTOWC(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
       btowc -- single byte to wide character conversion

SSYYNNOOPPSSIISS
       #include <stdio.h>
       #include <wchar.h>

       wint_t btowc(int _c);

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 _b_t_o_w_c() function shall determine whether _c constitutes a valid
       (one-byte) character in the initial shift state.

       The behavior of this function shall be affected by the _L_C___C_T_Y_P_E
       category of the current locale.

RREETTUURRNN VVAALLUUEE
       The _b_t_o_w_c() function shall return WEOF if _c has the value EOF or if
       ((uunnssiiggnneedd cchhaarr)) _c does not constitute a valid (one-byte) character in
       the initial shift state. Otherwise, it shall return the wide-character
       representation of that character.

       In the POSIX locale, _b_t_o_w_c() shall not return WEOF if _c has a value in
       the range 0 to 255 inclusive.

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
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _w_c_t_o_b()

       The Base Definitions volume of POSIX.1-2017, <<ssttddiioo..hh>>, <<wwcchhaarr..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                             BTOWC(3)
