iswblank(3) Library Functions Manual iswblank(3)

iswblank - test for whitespace wide character

Standard C library (libc, -lc)

#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

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'.

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

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
iswblank () Thread safety MT-Safe locale

POSIX.1-2008.

POSIX.1-2001.

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

isblank(3), iswctype(3)

2024-06-15 Linux man-pages 6.9.1