redhat man page for wcwidth

WCWIDTH(3)						     Linux Programmer's Manual							WCWIDTH(3)

NAME
       wcwidth - determine columns needed for a wide character

SYNOPSIS
       #include <wchar.h>

       int wcwidth(wchar_t c);

DESCRIPTION
       The  wcwidth function returns the number of columns needed to represent the wide character c. If c is a printable wide character, the value
       is at least 0. If c is L'', the value is 0. Otherwise -1 is returned.

RETURN VALUE
       The wcwidth function returns the number of column positions for c.

CONFORMING TO
       UNIX98. POSIX.1-2001.  Note that glibc before 2.2.5 used the prototype
       int wcwidth(wint_t c);

SEE ALSO
       wcswidth(3), iswprint(3)

NOTES
       The behaviour of wcwidth depends on the LC_CTYPE category of the current locale.

GNU
								    1999-07-25								WCWIDTH(3)