NAME
wcswidth — number
of column positions of a wide-character string
SYNOPSIS
int wcswidth(const wchar_t *pwcs, size_t n);
DESCRIPTION
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 shall not change
the setting of errno on valid input.
RETURN VALUE
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).
ERRORS
No errors are defined.
EXAMPLES
None.
APPLICATION USAGE
This function was removed from the final ISO/IEC 9899/AMD1:1995 (“ISO C90, Amendment 1”) (E), and the return value for a non-printable wide character is not specified.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
XBD V1_chap03(7), <wchar.h>
CHANGE HISTORY
First released in Issue 4. Derived from the MSE working draft.
Issue 6
The Open Group Corrigendum U021/11 is applied. The function is marked as an extension.
Issue 8
Austin Group Defect 448 is applied, adding a requirement that
wcswidth () does not change the setting of
errno on valid input.