Used for defining a character class. The value returned by this
function is used in calls to the iswctype function.
Format
#include <wctype.h> (ISO C)
#include <wchar.h> (XPG4)
wctype_t wctype (const char *char_class);
1 – Argument
char_class
A pointer to a valid character class name.
2 – Description
The wctype function converts a valid character class defined for
the current locale to an object of type wctype_t. The following
character class names are defined for all locales:
alnum cntrl lower space
alpha digit print upper
blank graph punct xdigit
Additional character class names may also be defined in the LC_
CTYPE category of the current locale.
See also iswctype.
3 – Return Values
x An object of type wctype_t that can be used in
calls to the iswctype function.
0 If the character class name is not valid for
the current locale.
4 – Example
#include <locale.h>
#include <wchar.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
/* This test will set up a number of character class using wctype() */
/* and then verify whether calls to iswctype() using these classes */
/* produce the same results as calls to the is**** routines. */
main()
{
wchar_t w_char;
wctype_t ret_val;
char *character = "A";
/* Convert character to wide character format - w_char */
if (mbtowc(&w_char, character, 1) == -1) {
perror("mbtowc");
exit(EXIT_FAILURE);
}
/* Check if results from iswalnum() matches check on */
/* alnum character class */
if ((iswalnum((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("alnum"))))
printf("[%C] is a member of the character class alnum\n", w_char);
else
printf("[%C] is not a member of the character class alnum\n", w_char);
/* Check if results from iswalpha() matches check on */
/* alpha character class */
if ((iswalpha((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("alpha"))))
printf("[%C] is a member of the character class alpha\n", w_char);
else
printf("[%C] is not a member of the character class alpha\n", w_char);
/* Check if results from iswcntrl() matches check on */
/* cntrl character class */
if ((iswcntrl((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("cntrl"))))
printf("[%C] is a member of the character class cntrl\n", w_char);
else
printf("[%C] is not a member of the character class cntrl\n", w_char);
/* Check if results from iswdigit() matches check on */
/* digit character class */
if ((iswdigit((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("digit"))))
printf("[%C] is a member of the character class digit\n", w_char);
else
printf("[%C] is not a member of the character class digit\n", w_char);
/* Check if results from iswgraph() matches check on */
/* graph character class */
if ((iswgraph((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("graph"))))
printf("[%C] is a member of the character class graph\n", w_char);
else
printf("[%C] is not a member of the character class graph\n", w_char);
/* Check if results from iswlower() matches check on */
/* lower character class */
if ((iswlower((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("lower"))))
printf("[%C] is a member of the character class lower\n", w_char);
else
printf("[%C] is not a member of the character class lower\n", w_char);
/* Check if results from iswprint() matches check on */
/* print character class */
if ((iswprint((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("print"))))
printf("[%C] is a member of the character class print\n", w_char);
else
printf("[%C] is not a member of the character class print\n", w_char);
/* Check if results from iswpunct() matches check on */
/* punct character class */
if ((iswpunct((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("punct"))))
printf("[%C] is a member of the character class punct\n", w_char);
else
printf("[%C] is not a member of the character class punct\n", w_char);
/* Check if results from iswspace() matches check on */
/* space character class */
if ((iswspace((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("space"))))
printf("[%C] is a member of the character class space\n", w_char);
else
printf("[%C] is not a member of the character class space\n", w_char);
/* Check if results from iswupper() matches check on */
/* upper character class */
if ((iswupper((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("upper"))))
printf("[%C] is a member of the character class upper\n", w_char);
else
printf("[%C] is not a member of the character class upper\n", w_char);
/* Check if results from iswxdigit() matches check on */
/* xdigit character class */
if ((iswxdigit((wint_t) w_char)) &&
(iswctype((wint_t) w_char, wctype("xdigit"))))
printf("[%C] is a member of the character class xdigit\n", w_char);
else
printf("[%C] is not a member of the character class xdigit\n", w_char);
}
Running this example produces the following result:
[A] is a member of the character class alnum
[A] is a member of the character class alpha
[A] is not a member of the character class cntrl
[A] is not a member of the character class digit
[A] is a member of the character class graph
[A] is not a member of the character class lower
[A] is a member of the character class print
[A] is not a member of the character class punct
[A] is not a member of the character class space
[A] is a member of the character class upper
[A] is a member of the character class xdigit