redhat man page for iswblank

ISWBLANK(3)						     Linux Programmer's Manual						       ISWBLANK(3)

NAME
       iswblank - test for whitespace wide character

SYNOPSIS
       #include <wctype.h>

       int iswblank(wint_t wc);

DESCRIPTION
       The  iswblank  function	is the wide-character equivalent of the isblank 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 '	'.

RETURN VALUE
       The iswblank function returns non-zero if wc is a wide character belonging to the wide character class "blank". Otherwise it returns zero.

CONFORMING TO
       This function is a GNU extension.

SEE ALSO
       isblank(3), iswctype(3)

NOTES
       The behaviour of iswblank depends on the LC_CTYPE category of the current locale.

GNU
								    1999-07-25							       ISWBLANK(3)