'\" et
.TH wchar.h "0P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
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.
.\"
.SH NAME
wchar.h
\(em wide-character handling
.SH SYNOPSIS
.LP
.nf
#include <wchar.h>
.fi
.SH DESCRIPTION
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\(hy2017,
.IR "Section 2.2" ", " "The Compilation Environment")
to enable the visibility of these symbols in this header.
.P
The
.IR <wchar.h> 
header shall define the following types:
.IP "\fBFILE\fP" 12
As described in
.IR <stdio.h> .
.IP "\fBlocale_t\fP" 12
As described in
.IR <locale.h> .
.IP "\fBmbstate_t\fP" 12
An object type other than an array type that can hold the conversion
state information necessary to convert between sequences of (possibly
multi-byte) characters and wide characters.
If a codeset is being used such that an
.BR mbstate_t
needs to preserve more than two levels of reserved state, the
results are unspecified.
.IP "\fBsize_t\fP" 12
As described in
.IR <stddef.h> .
.IP "\fBva_list\fP" 12
As described in
.IR <stdarg.h> .
.IP "\fBwchar_t\fP" 12
As described in
.IR <stddef.h> .
.IP "\fBwctype_t\fP" 12
A scalar type of a data object that can hold values which represent
locale-specific character classification.
.IP "\fBwint_t\fP" 12
An integer type capable of storing any valid value of
.BR wchar_t
or WEOF.
.P
The tag
.BR tm
shall be declared as naming an incomplete structure type, the contents
of which are described in the
.IR <time.h> 
header.
.P
The implementation shall support one or more programming environments
in which the width of
.BR wint_t
is no greater than the width of type
.BR long .
The names of these programming environments can be obtained using the
\fIconfstr\fR()
function or the
.IR getconf
utility.
.P
The
.IR <wchar.h> 
header shall define the following macros:
.IP WCHAR_MAX 12
As described in
.IR <stdint.h> .
.IP WCHAR_MIN 12
As described in
.IR <stdint.h> .
.IP WEOF 12
Constant expression of type
.BR wint_t
that is returned by several WP functions to indicate end-of-file.
.IP NULL 12
As described in
.IR <stddef.h> .
.P
Inclusion of the
.IR <wchar.h> 
header may make visible all symbols from the headers
.IR <ctype.h> ,
.IR <string.h> ,
.IR <stdarg.h> ,
.IR <stddef.h> ,
.IR <stdio.h> ,
.IR <stdlib.h> ,
and
.IR <time.h> .
.P
The following shall be declared as functions and may also be defined
as macros. Function prototypes shall be provided for use with ISO\ C standard
compilers. Arguments to functions in this list can point to arrays
containing
.BR wchar_t
values that do not correspond to members of the character set of the
current locale. Such values shall be processed according to the
specified semantics, unless otherwise stated.
.sp
.RS 4
.nf

wint_t        btowc(int);
wint_t        fgetwc(FILE *);
wchar_t      *fgetws(wchar_t *restrict, int, FILE *restrict);
wint_t        fputwc(wchar_t, FILE *);
int           fputws(const wchar_t *restrict, FILE *restrict);
int           fwide(FILE *, int);
int           fwprintf(FILE *restrict, const wchar_t *restrict, ...);
int           fwscanf(FILE *restrict, const wchar_t *restrict, ...);
wint_t        getwc(FILE *);
wint_t        getwchar(void);
int           iswalnum(wint_t);
int           iswalpha(wint_t);
int           iswcntrl(wint_t);
int           iswctype(wint_t, wctype_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);
size_t        mbrlen(const char *restrict, size_t, mbstate_t *restrict);
size_t        mbrtowc(wchar_t *restrict, const char *restrict, size_t,
                  mbstate_t *restrict);
int           mbsinit(const mbstate_t *);
size_t        mbsnrtowcs(wchar_t *restrict, const char **restrict,
                  size_t, size_t, mbstate_t *restrict);
size_t        mbsrtowcs(wchar_t *restrict, const char **restrict, size_t,
                  mbstate_t *restrict);
FILE         *open_wmemstream(wchar_t **, size_t *);
wint_t        putwc(wchar_t, FILE *);
wint_t        putwchar(wchar_t);
int           swprintf(wchar_t *restrict, size_t,
                  const wchar_t *restrict, ...);
int           swscanf(const wchar_t *restrict,
                  const wchar_t *restrict, ...);
wint_t        towlower(wint_t);
wint_t        towupper(wint_t);
wint_t        ungetwc(wint_t, FILE *);
int           vfwprintf(FILE *restrict, const wchar_t *restrict, va_list);
int           vfwscanf(FILE *restrict, const wchar_t *restrict, va_list);
int           vswprintf(wchar_t *restrict, size_t,
                  const wchar_t *restrict, va_list);
int           vswscanf(const wchar_t *restrict, const wchar_t *restrict,
                  va_list);
int           vwprintf(const wchar_t *restrict, va_list);
int           vwscanf(const wchar_t *restrict, va_list);
wchar_t      *wcpcpy(wchar_t *restrict, const wchar_t *restrict);
wchar_t      *wcpncpy(wchar_t *restrict, const wchar_t *restrict, size_t);
size_t        wcrtomb(char *restrict, wchar_t, mbstate_t *restrict);
int           wcscasecmp(const wchar_t *, const wchar_t *);
int           wcscasecmp_l(const wchar_t *, const wchar_t *, locale_t);
wchar_t      *wcscat(wchar_t *restrict, const wchar_t *restrict);
wchar_t      *wcschr(const wchar_t *, wchar_t);
int           wcscmp(const wchar_t *, const wchar_t *);
int           wcscoll(const wchar_t *, const wchar_t *);
int           wcscoll_l(const wchar_t *, const wchar_t *, locale_t);
wchar_t      *wcscpy(wchar_t *restrict, const wchar_t *restrict);
size_t        wcscspn(const wchar_t *, const wchar_t *);
wchar_t      *wcsdup(const wchar_t *);
size_t        wcsftime(wchar_t *restrict, size_t,
                  const wchar_t *restrict, const struct tm *restrict);
size_t        wcslen(const wchar_t *);
int           wcsncasecmp(const wchar_t *, const wchar_t *, size_t);
int           wcsncasecmp_l(const wchar_t *, const wchar_t *, size_t,
                  locale_t);
wchar_t      *wcsncat(wchar_t *restrict, const wchar_t *restrict, size_t);
int           wcsncmp(const wchar_t *, const wchar_t *, size_t);
wchar_t      *wcsncpy(wchar_t *restrict, const wchar_t *restrict, size_t);
size_t        wcsnlen(const wchar_t *, size_t);
size_t        wcsnrtombs(char *restrict, const wchar_t **restrict, size_t,
                  size_t, mbstate_t *restrict);
wchar_t      *wcspbrk(const wchar_t *, const wchar_t *);
wchar_t      *wcsrchr(const wchar_t *, wchar_t);
size_t        wcsrtombs(char *restrict, const wchar_t **restrict,
                  size_t, mbstate_t *restrict);
size_t        wcsspn(const wchar_t *, const wchar_t *);
wchar_t      *wcsstr(const wchar_t *restrict, const wchar_t *restrict);
double        wcstod(const wchar_t *restrict, wchar_t **restrict);
float         wcstof(const wchar_t *restrict, wchar_t **restrict);
wchar_t      *wcstok(wchar_t *restrict, const wchar_t *restrict,
                  wchar_t **restrict);
long          wcstol(const wchar_t *restrict, wchar_t **restrict, int);
long double   wcstold(const wchar_t *restrict, wchar_t **restrict);
long long     wcstoll(const wchar_t *restrict, wchar_t **restrict, int);
unsigned long wcstoul(const wchar_t *restrict, wchar_t **restrict, int);
unsigned long long
              wcstoull(const wchar_t *restrict, wchar_t **restrict, int);
int           wcswidth(const wchar_t *, size_t);
size_t        wcsxfrm(wchar_t *restrict, const wchar_t *restrict, size_t);
size_t        wcsxfrm_l(wchar_t *restrict, const wchar_t *restrict,
                  size_t, locale_t);
int           wctob(wint_t);
wctype_t      wctype(const char *);
int           wcwidth(wchar_t);
wchar_t      *wmemchr(const wchar_t *, wchar_t, size_t);
int           wmemcmp(const wchar_t *, const wchar_t *, size_t);
wchar_t      *wmemcpy(wchar_t *restrict, const wchar_t *restrict, size_t);
wchar_t      *wmemmove(wchar_t *, const wchar_t *, size_t);
wchar_t      *wmemset(wchar_t *, wchar_t, size_t);
int           wprintf(const wchar_t *restrict, ...);
int           wscanf(const wchar_t *restrict, ...);
.fi
.P
.RE
.LP
.IR "The following sections are informative."
.SH "APPLICATION USAGE"
The
\fIiswblank\fR()
function was a late addition to the ISO\ C standard and was introduced at the same
time as the ISO\ C standard introduced
.IR <wctype.h> ,
which contains all of the
.IR isw* (\|)
functions. The Open Group Base Specifications had previously aligned
with the MSE working draft and had introduced the rest of the
.IR isw* (\|)
functions into
.IR <wchar.h> .
For backwards-compatibility, the original set of
.IR isw* (\|)
functions, without
\fIiswblank\fR(),
are permitted (as part of the XSI option) in
.IR <wchar.h> .
For maximum portability, applications should include
.IR <wctype.h> 
in order to obtain declarations for the
.IR isw* (\|)
functions. This compatibility has been made obsolescent.
.SH RATIONALE
In the ISO\ C standard, the symbols referenced as XSI extensions are in
.IR <wctype.h> .
Their presence here is thus an extension.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fB<ctype.h>\fP",
.IR "\fB<locale.h>\fP",
.IR "\fB<stdarg.h>\fP",
.IR "\fB<stddef.h>\fP",
.IR "\fB<stdint.h>\fP",
.IR "\fB<stdio.h>\fP",
.IR "\fB<stdlib.h>\fP",
.IR "\fB<string.h>\fP",
.IR "\fB<time.h>\fP",
.IR "\fB<wctype.h>\fP"
.P
.ad l
The System Interfaces volume of POSIX.1\(hy2017,
.IR "Section 2.2" ", " "The Compilation Environment",
.IR "\fIbtowc\fR\^(\|)",
.IR "\fIconfstr\fR\^(\|)",
.IR "\fIfgetwc\fR\^(\|)",
.IR "\fIfgetws\fR\^(\|)",
.IR "\fIfputwc\fR\^(\|)",
.IR "\fIfputws\fR\^(\|)",
.IR "\fIfwide\fR\^(\|)",
.IR "\fIfwprintf\fR\^(\|)",
.IR "\fIfwscanf\fR\^(\|)",
.IR "\fIgetwc\fR\^(\|)",
.IR "\fIgetwchar\fR\^(\|)",
.IR "\fIiswalnum\fR\^(\|)",
.IR "\fIiswalpha\fR\^(\|)",
.IR "\fIiswcntrl\fR\^(\|)",
.IR "\fIiswctype\fR\^(\|)",
.IR "\fIiswdigit\fR\^(\|)",
.IR "\fIiswgraph\fR\^(\|)",
.IR "\fIiswlower\fR\^(\|)",
.IR "\fIiswprint\fR\^(\|)",
.IR "\fIiswpunct\fR\^(\|)",
.IR "\fIiswspace\fR\^(\|)",
.IR "\fIiswupper\fR\^(\|)",
.IR "\fIiswxdigit\fR\^(\|)",
.IR "\fImbrlen\fR\^(\|)",
.IR "\fImbrtowc\fR\^(\|)",
.IR "\fImbsinit\fR\^(\|)",
.IR "\fImbsrtowcs\fR\^(\|)",
.IR "\fIopen_memstream\fR\^(\|)",
.IR "\fIputwc\fR\^(\|)",
.IR "\fIputwchar\fR\^(\|)",
.IR "\fItowlower\fR\^(\|)",
.IR "\fItowupper\fR\^(\|)",
.IR "\fIungetwc\fR\^(\|)",
.IR "\fIvfwprintf\fR\^(\|)",
.IR "\fIvfwscanf\fR\^(\|)",
.IR "\fIwcrtomb\fR\^(\|)",
.IR "\fIwcscasecmp\fR\^(\|)",
.IR "\fIwcscat\fR\^(\|)",
.IR "\fIwcschr\fR\^(\|)",
.IR "\fIwcscmp\fR\^(\|)",
.IR "\fIwcscoll\fR\^(\|)",
.IR "\fIwcscpy\fR\^(\|)",
.IR "\fIwcscspn\fR\^(\|)",
.IR "\fIwcsdup\fR\^(\|)",
.IR "\fIwcsftime\fR\^(\|)",
.IR "\fIwcslen\fR\^(\|)",
.IR "\fIwcsncat\fR\^(\|)",
.IR "\fIwcsncmp\fR\^(\|)",
.IR "\fIwcsncpy\fR\^(\|)",
.IR "\fIwcspbrk\fR\^(\|)",
.IR "\fIwcsrchr\fR\^(\|)",
.IR "\fIwcsrtombs\fR\^(\|)",
.IR "\fIwcsspn\fR\^(\|)",
.IR "\fIwcsstr\fR\^(\|)",
.IR "\fIwcstod\fR\^(\|)",
.IR "\fIwcstok\fR\^(\|)",
.IR "\fIwcstol\fR\^(\|)",
.IR "\fIwcstoul\fR\^(\|)",
.IR "\fIwcswidth\fR\^(\|)",
.IR "\fIwcsxfrm\fR\^(\|)",
.IR "\fIwctob\fR\^(\|)",
.IR "\fIwctype\fR\^(\|)",
.IR "\fIwcwidth\fR\^(\|)",
.IR "\fIwmemchr\fR\^(\|)",
.IR "\fIwmemcmp\fR\^(\|)",
.IR "\fIwmemcpy\fR\^(\|)",
.IR "\fIwmemmove\fR\^(\|)",
.IR "\fIwmemset\fR\^(\|)"
.ad b
.P
The Shell and Utilities volume of POSIX.1\(hy2017,
.IR "\fIgetconf\fR\^"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
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.opengroup.org/unix/online.html .
.PP
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
https://www.kernel.org/doc/man-pages/reporting_bugs.html .