WCWIDTH(3)

NAME
wcwidth, wcwidth_l - number of column positions of a wide-character code

LIBRARY
libc

SYNOPSIS
#include <wchar.h>
int
wcwidth(wchar_t wc);
#include <xlocale.h>
int
wcwidth_l(wchar_t wc, locale_t locale);

DESCRIPTION
The wcwidth() and wcwidth_l() functions determine the number of column positions required to display the wide character wc.

The wcwidth_l() function takes an explicit locale argument, whereas the wcwidth() function uses the current global or per-thread locale.

RETURN VALUES
The wcwidth() and wcwidth_l() functions return 0 if the wc argument is a null wide character (L'\0'), -1 if wc is not printable, otherwise they return 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 p1003.1-2001.