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6.28 wcwidth—number of column positions of a wide-character code

Synopsis

     #include <wchar.h>
     int wcwidth(const wchar_t wc);
     

Description
The wcwidth function shall determine the number of column positions required for the wide character wc. The application shall ensure that the value of wc is a character representable as a wchar_t, and is a wide-character code corresponding to a valid character in the current locale.


Returns
The wcwidth function shall either return 0 (if wc is a null wide-character code), or return the number of column positions to be occupied by the wide-character code wc, or return -1 (if wc does not correspond to a printable wide-character code).

The current implementation of wcwidth simply sets the width of all printable characters to 1 since newlib has no character tables around.


Portability
wcwidth has been introduced in the Single UNIX Specification Volume 2. wcwidth has been marked as an extension in the Single UNIX Specification Volume 3.