iswblank
(3)test for whitespace wide character
#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
LIBRARY
DESCRIPTION
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'.