This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
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 POSIX.1‐2008, Section2.2, The Compilation Environment) to enable the visibility of these
symbols in this header.
The <wctype.h> header shall define the following types:
wint_t As described in <wchar.h>.
wctrans_t A scalar type that can hold values which represent
locale-specific character mappings.
wctype_t As described in <wchar.h>.
The <wctype.h> header shall define the locale_t type as described in
The <wctype.h> header shall define the following macro:
WEOF As described in <wchar.h>.
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
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 shall be declared as functions and may also be defined
as macros. Function prototypes shall be provided for use with ISO C
int iswalnum(wint_t);int iswalnum_l(wint_t, locale_t);int iswalpha(wint_t);int iswalpha_l(wint_t, locale_t);int iswblank(wint_t);int iswblank_l(wint_t, locale_t);int iswcntrl(wint_t);int iswcntrl_l(wint_t, locale_t);int iswctype(wint_t, wctype_t);int iswctype_l(wint_t, wctype_t, locale_t);int iswdigit(wint_t);int iswdigit_l(wint_t, locale_t);int iswgraph(wint_t);int iswgraph_l(wint_t, locale_t);int iswlower(wint_t);int iswlower_l(wint_t, locale_t);int iswprint(wint_t);int iswprint_l(wint_t, locale_t);int iswpunct(wint_t);int iswpunct_l(wint_t, locale_t);int iswspace(wint_t);int iswspace_l(wint_t, locale_t);int iswupper(wint_t);int iswupper_l(wint_t, locale_t);int iswxdigit(wint_t);int iswxdigit_l(wint_t, locale_t);wint_t towctrans(wint_t, wctrans_t);wint_t towctrans_l(wint_t, wctrans_t, locale_t);wint_t towlower(wint_t);wint_t towlower_l(wint_t, locale_t);wint_t towupper(wint_t);wint_t towupper_l(wint_t, locale_t);wctrans_t wctrans(const char *);wctrans_t wctrans_l(const char *, locale_t);wctype_t wctype(const char *);wctype_t wctype_l(const char *, locale_t);The following sections are informative.
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) In the event of any discrepancy between this version and
the original IEEE and The Open Group Standard, the original IEEE and
The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
IEEE/The Open Group 2013 wctype.h(0P)