wcwidth3

Usage

Library

Standard C Library (libc, -lc)

Overview

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;
}