php man page for iswxdigit

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

NAME
       iswxdigit - test for hexadecimal digit wide character

SYNOPSIS
       #include <wctype.h>

       int iswxdigit(wint_t wc);

DESCRIPTION
       The  iswxdigit()  function is the wide-character equivalent of the isxdigit(3) function.  It tests whether wc is a wide character belonging
       to the wide-character class "xdigit".

       The wide-character class "xdigit" is a subclass of the wide-character class "alnum", and therefore also a subclass  of  the  wide-character
       class "graph" and of the wide-character class "print".

       Being a subclass of the wide-character class "print", the wide-character class "xdigit" is disjoint from the wide-character class "cntrl".

       Being  a  subclass of the wide-character class "graph", the wide-character class "xdigit" is disjoint from the wide-character class "space"
       and its subclass "blank".

       Being a subclass of the wide-character class "alnum", the wide-character class "xdigit" is disjoint from the wide-character class "punct".

       The wide-character class "xdigit" always contains at least the letters 'A' to 'F', 'a' to 'f' and the digits '0' to '9'.

RETURN VALUE
       The iswxdigit() function returns nonzero if wc is a wide character belonging to the wide-character class "xdigit".  Otherwise,  it  returns
       zero.

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

       +------------+---------------+----------------+
       |Interface   | Attribute     | Value	     |
       +------------+---------------+----------------+
       |iswxdigit() | Thread safety | MT-Safe locale |
       +------------+---------------+----------------+
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, C99.

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

SEE ALSO
       iswctype(3), isxdigit(3)

COLOPHON
       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU
								    2015-08-08							      ISWXDIGIT(3)