NAME

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

SYNOPSIS

[XSI] #include <wchar.h>

int wcwidth(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.

The wcwidth() function shall not change the setting of errno on valid input.

RETURN VALUE

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).

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

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.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

wcswidth

XBD <wchar.h>

CHANGE HISTORY

First released as a World-wide Portability Interface in Issue 4. Derived from the MSE working draft.

Issue 6

The Open Group Corrigendum U021/12 is applied. This function is marked as an extension.

The normative text is updated to avoid use of the term "must" for application requirements.

Issue 8

Austin Group Defect 448 is applied, adding a requirement that wcwidth() does not change the setting of errno on valid input.