DragonFly On-Line Manual Pages


WCWIDTH(3)	      DragonFly 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 <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 IEEE Std 1003.1-2001 (``POSIX.1''). DragonFly 3.9 December 27, 2013 DragonFly 3.9