This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       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                                      wctype.h(7POSIX)

       Some of the functionality described on this reference page extends the ISO C standard. Applications shall
       define the appropriate feature test macro (see the System Interfaces volume of POSIX.1‐2017, Section2.2,
       TheCompilationEnvironment) to enable the visibility of these symbols in this header.

       The <wctype.h> header shall define the following types:

       wint_t      As described in <wchar.h>.

       wctrans_t   A scalar type that can hold values which represent locale-specific character mappings.

       wctype_t    As described in <wchar.h>.

       The <wctype.h> header shall define the locale_t type as described in <locale.h>.

       The <wctype.h> header shall define the following macro:

       WEOF        As described in <wchar.h>.

       For  all  functions  described  in  this  header  that  accept  an  argument of type wint_t, the value is
       representable as a wchar_t or equals the value of WEOF.  If  this  argument  has  any  other  value,  the
       behavior is undefined.

       The behavior of these functions shall be affected by the LC_CTYPE category of the current locale.

       Inclusion  of  the <wctype.h> header may make visible all symbols from the headers <ctype.h>, <stdarg.h>,
       <stddef.h>, <stdio.h>, <stdlib.h>, <string.h>, <time.h>, and <wchar.h>.

       The following shall be declared as functions and may also be defined as macros. Function prototypes shall
       be provided for use with ISO C standard compilers.

           int       iswalnum(wint_t);
           int       iswalnum_l(wint_t, locale_t);
           int       iswalpha(wint_t);
           int       iswalpha_l(wint_t, locale_t);
           int       iswblank(wint_t);
           int       iswblank_l(wint_t, locale_t);
           int       iswcntrl(wint_t);
           int       iswcntrl_l(wint_t, locale_t);
           int       iswctype(wint_t, wctype_t);
           int       iswctype_l(wint_t, wctype_t, locale_t);
           int       iswdigit(wint_t);
           int       iswdigit_l(wint_t, locale_t);
           int       iswgraph(wint_t);
           int       iswgraph_l(wint_t, locale_t);
           int       iswlower(wint_t);
           int       iswlower_l(wint_t, locale_t);
           int       iswprint(wint_t);
           int       iswprint_l(wint_t, locale_t);
           int       iswpunct(wint_t);
           int       iswpunct_l(wint_t, locale_t);
           int       iswspace(wint_t);
           int       iswspace_l(wint_t, locale_t);
           int       iswupper(wint_t);
           int       iswupper_l(wint_t, locale_t);
           int       iswxdigit(wint_t);
           int       iswxdigit_l(wint_t, locale_t);
           wint_t    towctrans(wint_t, wctrans_t);
           wint_t    towctrans_l(wint_t, wctrans_t, locale_t);
           wint_t    towlower(wint_t);
           wint_t    towlower_l(wint_t, locale_t);
           wint_t    towupper(wint_t);
           wint_t    towupper_l(wint_t, locale_t);
           wctrans_t wctrans(const char *);
           wctrans_t wctrans_l(const char *, locale_t);
           wctype_t  wctype(const char *);
           wctype_t  wctype_l(const char *, locale_t);

       Thefollowingsectionsareinformative.

       None.

       wctype.h — wide-character classification and mapping utilities

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

       None.

<ctype.h>, <locale.h>, <stdarg.h>, <stddef.h>, <stdio.h>, <stdlib.h>, <string.h>, <time.h>, <wchar.h>

       The System Interfaces volume of POSIX.1‐2017,  Section2.2,  TheCompilationEnvironment,  iswalnum(),
       iswalpha(),   iswblank(),   iswcntrl(),   iswctype(),  iswdigit(),  iswgraph(),  iswlower(),  iswprint(),
       iswpunct(),  iswspace(),  iswupper(),  iswxdigit(),  setlocale(),  towctrans(),  towlower(),  towupper(),
       wctrans(), wctype()

       #include <wctype.h>