iswblank(3) — Linux manual page

iswblank(3)              Library Functions Manual             iswblank(3)

NAME         top

       iswblank - test for whitespace wide character

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <wctype.h>

       int iswblank(wint_t wc);

   Feature Test Macro Requirements for glibc (see
   feature_test_macros(7)):

       iswblank():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

DESCRIPTION         top

       The iswblank() function is the wide-character equivalent of the
       isblank(3) function.  It tests whether wc is a wide character
       belonging to the wide-character class "blank".

       The wide-character class "blank" is a subclass of the wide-
       character class "space".

       Being a subclass of the wide-character class "space", the wide-
       character class "blank" is disjoint from the wide-character class
       "graph" and therefore also disjoint from its subclasses "alnum",
       "alpha", "upper", "lower", "digit", "xdigit", "punct".

       The wide-character class "blank" always contains at least the
       space character and the control character '\t'.

RETURN VALUE         top

       The iswblank() function returns nonzero if wc is a wide character
       belonging to the wide-character class "blank".  Otherwise, it
       returns zero.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌───────────────────────────────┬───────────────┬────────────────┐
       │ Interface                     │ Attribute     │ Value          │
       ├───────────────────────────────┼───────────────┼────────────────┤
       │ iswblank()                    │ Thread safety │ MT-Safe locale │
       └───────────────────────────────┴───────────────┴────────────────┘

STANDARDS         top

       POSIX.1-2008.

HISTORY         top

       POSIX.1-2001.

NOTES         top

       The behavior of iswblank() depends on the LC_CTYPE category of the
       current locale.

SEE ALSO         top

       isblank(3), iswctype(3)

COLOPHON         top

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Linux man-pages 6.15            2025-05-17                    iswblank(3)

Pages that refer to this page: isalpha(3),  iswctype(3)

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