<wchar.h>(0P) POSIX Programmer's Manual <wchar.h>(0P)


wchar.h - wide-character handling


#include <wchar.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 <wchar.h> header shall define the following types:

As described in <stddef.h> .
An integer type capable of storing any valid value of wchar_t or WEOF.
A scalar type of a data object that can hold values which represent locale-specific character classification.
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 mbstate_t needs to preserve more than 2 levels of reserved state, the results are unspecified.
As described in <stdio.h> .
As described in <stddef.h> .
As described in <stdarg.h> .

The implementation shall support one or more programming environments in which the width of wint_t is no greater than the width of type long. The names of these programming environments can be obtained using the confstr() function or the getconf utility.

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.


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 mbsrtowcs(wchar_t *restrict, const char **restrict, size_t,
mbstate_t *restrict);
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 vwprintf(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,
int vwscanf(const wchar_t *restrict, va_list);
size_t wcrtomb(char *restrict, wchar_t, mbstate_t *restrict);
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 *);
wchar_t *wcscpy(wchar_t *restrict, const wchar_t *restrict);
size_t wcscspn(const wchar_t *, 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 *);
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);
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);

wchar_t *wcswcs(const wchar_t *, const wchar_t *);
int wcswidth(const wchar_t *, size_t);

size_t wcsxfrm(wchar_t *restrict, const wchar_t *restrict, size_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, ...);

The <wchar.h> header shall define the following macros:

The maximum value representable by an object of type wchar_t.
The minimum value representable by an object of type wchar_t.
Constant expression of type wint_t that is returned by several WP functions to indicate end-of-file.
As described in <stddef.h> .

The tag tm shall be declared as naming an incomplete structure type, the contents of which are described in the header <time.h> .

Inclusion of the <wchar.h> header may make visible all symbols from the headers <ctype.h>, <string.h>, <stdarg.h>, <stddef.h>, <stdio.h>, <stdlib.h>, and <time.h>.

The following sections are informative.


The iswblank() function was a late addition to the ISO C standard and was introduced at the same time as the ISO C standard introduced <wctype.h>, which contains all of the isw*() functions. The Open Group Base Specifications had previously aligned with the MSE working draft and had introduced the rest of the isw*() functions into <wchar.h>. For backwards-compatibility, the original set of isw*() functions, without iswblank(), are permitted (as an XSI extension) in <wchar.h>. For maximum portability, applications should include <wctype.h> in order to obtain declarations for the isw*() functions.


In the ISO C standard, the symbols referenced as XSI extensions are in <wctype.h>. Their presence here is thus an extension.




<ctype.h>, <stdarg.h>, <stddef.h>, <stdio.h>, <stdlib.h>, <string.h>, <time.h>, <wctype.h>, the System Interfaces volume of IEEE Std 1003.1-2001, btowc(), confstr(), fgetwc(), fgetws(), fputwc(), fputws(), fwide(), fwprintf(), fwscanf(), getwc(), getwchar(), iswalnum(), iswalpha(), iswcntrl(), iswctype(), iswdigit(), iswgraph(), iswlower(), iswprint(), iswpunct(), iswspace(), iswupper(), iswxdigit(), iswctype(), mbsinit(), mbrlen(), mbrtowc(), mbsrtowcs(), putwc(), putwchar(), swprintf(), swscanf(), towlower(), towupper(), ungetwc(), vfwprintf(), vfwscanf(), vswprintf(), vswscanf(), vwscanf(), wcrtomb(), wcsrtombs(), wcscat(), wcschr(), wcscmp(), wcscoll(), wcscpy(), wcscspn(), wcsftime(), wcslen(), wcsncat(), wcsncmp(), wcsncpy(), wcspbrk(), wcsrchr(), wcsspn(), wcsstr(), wcstod(), wcstof(), wcstok(), wcstol(), wcstold(), wcstoll(), wcstoul(), wcstoull(), wcswcs(), wcswidth(), wcsxfrm(), wctob(), wctype(), wcwidth(), wmemchr(), wmemcmp(), wmemcpy(), wmemmove(), wmemset(), wprintf(), wscanf(), the Shell and Utilities volume of IEEE Std 1003.1-2001, getconf


Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 .
2003 IEEE/The Open Group