WCWIDTH(3) BSD Library Functions Manual WCWIDTH(3)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 infor‐
mation.
RETURN VALUES
The wcwidth() function returns 0 if the wc argument is a null wide char‐
acter (L'\0'), -1 if wc is not printable; otherwise, it returns the num‐
ber 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 ALSOiswprint(3), wcswidth(3), xlocale(3)STANDARDS
The wcwidth() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).
BSD August 17, 2004 BSD
