PROLOG

       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.

NAME

       iswctype, iswctype_l — test character for a specified class

SYNOPSIS

       #include <wctype.h>

       int iswctype(wint_t wc, wctype_t charclass);
       int iswctype_l(wint_t wc, wctype_t charclass,
           locale_t locale);

DESCRIPTION

       For  iswctype():  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  iswctype() and iswctype_l() functions shall determine whether the wide-character code
       wc has the character  class  charclass,  returning  true  or  false.  The  iswctype()  and
       iswctype_l()  functions  are defined on WEOF and wide-character codes corresponding to the
       valid character encodings in the current locale, or in the locale represented  by  locale,
       respectively.  If  the  wc  argument  is  not in the domain of the function, the result is
       undefined.  If the value of charclass is invalid (that is,  not  obtained  by  a  call  to
       wctype() or charclass is invalidated by a subsequent call to setlocale() that has affected
       category LC_CTYPE) the result is unspecified.

       The behavior is undefined if the locale argument to iswctype_l()  is  the  special  locale
       object LC_GLOBAL_LOCALE or is not a valid locale object handle.

RETURN VALUE

       The  iswctype()  and iswctype_l() functions shall return non-zero (true) if and only if wc
       has the property described by charclass.  If charclass  is  (wctype_t)0,  these  functions
       shall return 0.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

   Testing for a Valid Character
           #include <wctype.h>
           ...
           int yes_or_no;
           wint_t wc;
           wctype_t valid_class;
           ...
           if ((valid_class=wctype("vowel")) == (wctype_t)0)
               /* Invalid character class. */
           yes_or_no=iswctype(wc,valid_class);

APPLICATION USAGE

       The twelve strings "alnum", "alpha", "blank", "cntrl", "digit", "graph", "lower", "print",
       "punct", "space", "upper", and "xdigit" are reserved for the standard  character  classes.
       In  the  table  below, the functions in the left column are equivalent to the functions in
       the right column.

           iswalnum(wc)            iswctype(wc, wctype("alnum"))
           iswalnum_l(wc, locale)  iswctype_l(wc, wctype("alnum"), locale)
           iswalpha(wc)            iswctype(wc, wctype("alpha"))
           iswalpha_l(wc, locale)  iswctype_l(wc, wctype("alpha"), locale)
           iswblank(wc)            iswctype(wc, wctype("blank"))
           iswblank_l(wc, locale)  iswctype_l(wc, wctype("blank"), locale)
           iswcntrl(wc)            iswctype(wc, wctype("cntrl"))
           iswcntrl_l(wc, locale)  iswctype_l(wc, wctype("cntrl"), locale)
           iswdigit(wc)            iswctype(wc, wctype("digit"))
           iswdigit_l(wc, locale)  iswctype_l(wc, wctype("digit"), locale)
           iswgraph(wc)            iswctype(wc, wctype("graph"))
           iswgraph_l(wc, locale)  iswctype_l(wc, wctype("graph"), locale)
           iswlower(wc)            iswctype(wc, wctype("lower"))
           iswlower_l(wc, locale)  iswctype_l(wc, wctype("lower"), locale)
           iswprint(wc)            iswctype(wc, wctype("print"))
           iswprint_l(wc, locale)  iswctype_l(wc, wctype("print"), locale)
           iswpunct(wc)            iswctype(wc, wctype("punct"))
           iswpunct_l(wc, locale)  iswctype_l(wc, wctype("punct"), locale)
           iswspace(wc)            iswctype(wc, wctype("space"))
           iswspace_l(wc, locale)  iswctype_l(wc, wctype("space"), locale)
           iswupper(wc)            iswctype(wc, wctype("upper"))
           iswupper_l(wc, locale)  iswctype_l(wc, wctype("upper"), locale)
           iswxdigit(wc)           iswctype(wc, wctype("xdigit"))
           iswxdigit_l(wc, locale) iswctype_l(wc, wctype("xdigit"), locale)

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       iswalnum(),  iswalpha(),  iswcntrl(),  iswdigit(),  iswgraph(),  iswlower(),   iswprint(),
       iswpunct(), iswspace(), iswupper(), iswxdigit(), setlocale(), uselocale(), wctype()

       The Base Definitions volume of POSIX.1‐2017, <locale.h>, <wctype.h>

COPYRIGHT

       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 .