NAME
wcwidth, wcwidth_l
— number of column positions of
a wide-character code
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include
<wchar.h>
int
wcwidth(wchar_t wc);
#include <wchar.h>
#include <xlocale.h>
int
wcwidth_l(wchar_t wc,
locale_t loc);
DESCRIPTION
The
wcwidth()
function determines the number of column positions required to display the
wide character wc.
Although the
wcwidth()
function uses the current locale, the
wcwidth_l()
function may be passed a locale directly. See
xlocale(3) for more information.
RETURN VALUES
The wcwidth() function returns 0 if the
wc argument is a null wide character (L'\0'), -1 if
wc is not printable; otherwise, it returns the number
of column positions the character occupies.
EXAMPLES
This code fragment reads text from standard input and breaks lines that are more than 20 column positions wide, similar to the fold(1) utility:
wint_t ch;
int column, w;
column = 0;
while ((ch = getwchar()) != WEOF) {
w = wcwidth(ch);
if (w > 0 && column + w >= 20) {
putwchar(L'\n');
column = 0;
}
putwchar(ch);
if (ch == L'\n')
column = 0;
else if (w > 0)
column += w;
}
SEE ALSO
STANDARDS
The wcwidth() function conforms to
IEEE Std 1003.1-2001 (“POSIX.1”).