iswctype(3)iswctype(3)NAMEiswctype - Determine the properties of a wide character
SYNOPSIS
#include <wctype.h>
int iswctype(
wint_t wc,
wctype_t wc_prop );
The XPG4 standard specifies that applications define this function by
including wchar.h rather than wctype.h, which is required by the cur‐
rent version of the ISO C standard. Both include statements are sup‐
ported.
LIBRARY
Standard C Library (libc)
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
iswctype(): ISO C, XPG4
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
PARAMETERS
Specifies the wide character to be tested. Specifies a handle for a
valid wide character property name as defined in the current locale.
DESCRIPTION
The iswctype() function tests the wide character specified by the wc
parameter to determine if it has the property specified by the wc_prop
parameter. The wctype() function associates a character property with a
wctype_t handle. You should get the value of the wc_prop parameter from
a call to wctype() before using it in a call to iswctype(). The iswc‐
type() function is defined for the wide-character null and for values
in the character range of the current code set defined in the current
locale.
Using an iswclass function, such as iswalnum(), is equivalent to using
the iswctype() and wctype() functions to test for a basic property,
such as alnum. However, iswctype() and wctype() can test wide charac‐
ters against any class defined in a locale; the functions are not lim‐
ited to testing for basic properties.
RETURN VALUES
If the wc parameter has the property specified by the wc_prop parame‐
ter, the iswctype() function returns a nonzero value. If the value
specified by the wc parameter does not have the property specified by
the wc_prop parameter, the iswctype() function returns a value of 0
(zero). If the value specified by the wc parameter is not in the func‐
tion's domain, the result is undefined. If the value specified by the
wc_prop parameter is not valid, the result is undefined. The value of
the wc_prop parameter can be invalid because it was not obtained by a
call to the wctype() function. The wc_prop value can also be invali‐
dated by an intervening call to the setlocale() function that has
affected the LC_CTYPE environment variable.
If the input value (wc) is not in the range of wide characters defined
by the current locale, the result is undefined. To check the range of
input values, compile applications with standard compile options such
as -DOPEN_SOURCE. If the application compiles with any of the standard
compile options, the interfaces documented in this reference page
resolve as functions, which perform internal range checking. A default
compilation (that is, no standard compile options specified) results in
resolution of the interfaces as macros, which do not perform internal
range checking.
EXAMPLES
The following example tests to determine if a wide character belongs to
the class of blank characters as defined for the current locale. In
this case, the required call to wctype() is included directly as the
wc_prop parameter:
iswctype(wc, wctype("blank")); The following example tests to
determine if a wide character is an uppercase character as
defined by the current locale. In this case, the required call
to wctype() is specified through a handle:
int yes_or_no; wint_t wc; wctype_t property_test;
.
.
. property_test=wctype("upper"); yes_or_no=iswctype(wc,prop‐
erty_test);
SEE ALSO
Functions: ctype(3), towctrans(3), wctrans(3), wctype(3), setlocale(3),
iswalnum(3)iswctype(3)