The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.
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NAME

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

SYNOPSIS

[XSI] [Option Start] #include <wchar.h>

int wcwidth(wchar_t wc); [Option End]

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.

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.

The following sections are informative.

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(), the Base Definitions volume of IEEE Std 1003.1-2001, <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 DESCRIPTION is updated to avoid use of the term "must" for application requirements.

End of informative text.
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