wcswidth - number of column positions of a wide-character string
The wcswidth() function shall determine the number of column positions required for n wide-character codes (or fewer than n wide-character codes if a null wide-character code is encountered before n wide-character codes are exhausted) in the string pointed to by pwcs.
The wcswidth() function either shall return 0 (if pwcs points to a null wide-character code), or return the number of column positions to be occupied by the wide-character string pointed to by pwcs, or return -1 (if any of the first n wide-character codes in the wide-character string pointed to by pwcs is not a printable wide-character code).
No errors are defined.
This function was removed from the final ISO/IEC 9899:1990/Amendment 1:1995 (E), and the return value for a non-printable wide character is not specified.
wcwidth() , the Base Definitions volume of IEEE Std 1003.1-2001, Section 3.103, Column Position, <wchar.h>
First released in Issue 4. Derived from the MSE working draft.
The Open Group Corrigendum U021/11 is applied. The function is marked as an extension.