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 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 is provided, which defines a macro, several types, and 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 widecharacter case-mapping functions, wctrans and towctrans.

- To the iibrary clause (clause 7), the additional header 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, wcstad for example;
• wide-string general utility functions, wcscpy for example;
• a wide-string time conversion function, wcsftime;
• restartable muitibyte/wide-character conversion functions, mbrtowc for example;
• restantable multibytd/wide-string conversion functions, mbsrtowcs and wcsrtombs.