NAME

wcwidth —

number of column positions of a wide-character code

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <wchar.h>

int
wcwidth(wchar_t wc);

DESCRIPTION

The wcwidth() function determines the number of column positions required to display the wide character wc.

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;
}

STANDARDS

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