wchar.h — ISO/C Multibyte Support extensions

The wchar.h header file contains the declaration for the supported subset of the ISO/C Multibyte Support extensions introduced in ISO/IEC 9899:1990/Amendment 1:1993(E) extensions. The following functions are declared in wchar.h:

btowc()

fgetwc()

fgetws()

fputwc()

fputws()

fwide()

fwprintf()

fwscanf()

getwc()

getwchar()

mbrlen()

mbrtowc()

mbsinit()

mbsrtowcs()

putwc()

putwchar()

swprintf()

swscanf()

ungetwc()

vfwprintf()

vfwscanf()

vswprintf()

vswscanf()

vwprintf()

vwscanf()

wcrtomb()

wcscat()

wcschr()

wcscmp()

wcscoll()

wcscpy()

wcscspn()

wcsftime()

wcslen()

wcsncat()

wcsncmp()

wcsncpy()

wcspbrk()

wcsrchr()

wcsrtombs()

wcsspn()

wcsstr()

wcstod()

wcstok()

wcstol()

wcstoll()

wcstoul()

wcstoull()

wcswidth()

wcsxfrm()

wctob()

wcwidth()

wmemchr()

wmemcpy()

wmemcmp()

wmemmove()

wmemset()

wprintf()

wscanf()

wcstod32()[1]

wcstod64()[1]

wcstod128()[1]

[1] The __STDC_WANT_DEC_FP__ feature test macro is required to expose decimal floating-point functionality.

wmemchr(), wmemcpy(), wmemcmp(), and wmemset() are also available as their built-in versions.

You don't need to include stdio.h and stdarg.h to use the header file.

The header file wchar.h contains definitions of the following types:

mbstate_t: Conversion-state information needed when converting between sequences of multibyte characters and wide characters.
size_t: typedef for the type of the value returned by sizeof.
wchar_t: typedef for a wide-character constant.
win_t: An integral type unchanged by integral promotions that can hold any value corresponding to members of the extended character set, as well as WEOF (see below).
FILE: The FILE structure type is defined in both stdio.h and wchar.h. Stream functions use a pointer to the FILE type to get access to a given stream. The system uses the information in the FILE structure to maintain the stream. The C standard streams stdin, stdout, and stderr are also defined in stdio.h.
va_list: This type is defined in both stdarg.h and wchar.h.

The header file wchar.h also contains definitions of the following constants:

NULL: A pointer that never points to a data object.
WEOF: Expands to a constant expression of type wint_t, whose value does not correspond to any member of the extended character set. It indicates End Of File (EOF).
WCHAR_MIN: Defines the lower limit of the wchar_t type.
WCHAR_MAX: Defines the upper limit of the wchar_t type.

You can perform wide-character input/output on the streams described in the ISO/IEC 9899:1990 standard, sub-clause 7.9.2. This standard expands the definition of a stream to include an orientation for both text and binary streams. For more information about DBCS orientation, see the topic on Double-Byte Characters Sets in z/OS XL C/C++ Programming Guide.

The wide-character string functions are also declared in wcstr.h for compatibility with previous releases of C/370, although wcstr.h may be withdrawn in the future.

For more information about the effect of locale, see setlocale(), locale.h, or look up the individual functions in this topic. For still more information, see the Internationalization: Locales and Character Sets in z/OS XL C/C++ Programming Guide.