#include <wctype.h>
Some of the functionality described on this reference page extends the ISO C standard. Applications shall define the appropriate feature test macro (see the System Interfaces volume of IEEE Std 1003.1-2001, Section 2.2, The Compilation Environment) to enable the visibility of these symbols in this header.
The <wctype.h> header shall define the following types:
The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.
int iswalnum(wint_t); int iswalpha(wint_t); int iswblank(wint_t); int iswcntrl(wint_t); int iswdigit(wint_t); int iswgraph(wint_t); int iswlower(wint_t); int iswprint(wint_t); int iswpunct(wint_t); int iswspace(wint_t); int iswupper(wint_t); int iswxdigit(wint_t); int iswctype(wint_t, wctype_t); wint_t towctrans(wint_t, wctrans_t); wint_t towlower(wint_t); wint_t towupper(wint_t); wctrans_t wctrans(const char *); wctype_t wctype(const char *);
The <wctype.h> header shall define the following macro name:
For all functions described in this header that accept an argument of type wint_t, the value is representable as a wchar_t or equals the value of WEOF. If this argument has any other value, the behavior is undefined.
The behavior of these functions shall be affected by the LC_CTYPE category of the current locale.
Inclusion of the <wctype.h> header may make visible all symbols from the headers <ctype.h>, <stdarg.h>, <stddef.h>, <stdio.h>, <stdlib.h>, <string.h>, <time.h>, and <wchar.h>.
The following sections are informative.
<ctype.h>, <locale.h>, <stdarg.h>, <stddef.h>, <stdio.h>, <stdlib.h>, <string.h>, <time.h>, <wchar.h>, the System Interfaces volume of IEEE Std 1003.1-2001, iswalnum(), iswalpha(), iswblank(), iswcntrl(), iswctype(), iswdigit(), iswgraph(), iswlower(), iswprint(), iswpunct(), iswspace(), iswupper(), iswxdigit(), setlocale(), towctrans(), towlower(), towupper(), wctrans(), wctype()