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Scope

This amendment defines extensions to ISO/IEC 9899:1990 that provide a more complete set of multibyte and wide-character utilities, as well as alternative spellings for certain tokens. Use of these features can help promote international portability of C programs.

This amendment specifies extensions that affect various clauses of ISO/IEC 9899:1990:

- To the compliance clause (clause 4), the additional header <iso6 46.h> is provided by both freestanding and hosted implementations. - To the language clause (clause 6), six additional tokens are accepted. - To the library clause (clause 7), new capabilities are specified for the existing formatted input/output functions (7.9.6). - To the library clause (clause 7), the additional header < wctype.h> is provided, which defines a macro, several types, a nd many functions, including: - wide-character testing functions, iswalnum for example; - extensible wide-character classification functions, wctype and iswctype; - wide-character case-mapping functions, towlower and towupper; - extensible wide-character case-mapping functions, wctrans and towctrans.

- To the library clause (clause 7), the additional header < wchar.h> is provided, which defines several macros, several types, and many functions, including: - formatted wide-character input/output functions, fwprintf for example; - wide-character input/output functions, fgetwc for example; - wide-string numeric conversion functions, wcstod for example; - wide-string general utility functions, wcscpy for example; - a wide-string time conversion function, wcsftime; - restartable multibyte/wide-character conversion functions, mbrtowc for example; - restartable multibyte/wide-string conversion functions, mbsrtowcs and wcsrtombs.