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

       iswblank, iswblank_l — test for a blank wide-character code

SYNOPSIS

       #include <wctype.h>

       int iswblank(wint_t wc);
       int iswblank_l(wint_t wc, locale_t locale);

DESCRIPTION

       For  iswblank():  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  iswblank()  and  iswblank()  functions shall test whether wc is a wide-character code
       representing a character  of  class  blank  in  the  current  locale,  or  in  the  locale
       represented  by  locale,  respectively;  see  the Base Definitions volume of POSIX.1‐2017,
       Chapter 7, Locale.

       The wc argument is a wint_t, the value of which the application shall ensure  is  a  wide-
       character  code  corresponding to a valid character in the locale used by the function, or
       equal to the value of the macro WEOF. If the argument has any other value, the behavior is
       undefined.

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

RETURN VALUE

       The iswblank() and iswblank_l() functions shall return non-zero if wc  is  a  blank  wide-
       character code; otherwise, they shall return 0.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       To  ensure  applications  portability,  especially  across  natural  languages, only these
       functions and the functions in the reference pages listed in the SEE ALSO  section  should
       be used for character classification.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

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

       The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale, <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 .