Reference

wcwidth(3)

number of column positions of a wide-character code

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

iswprint(3), wcswidth(3), xlocale(3)

STANDARDS

The wcwidth() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

History