WCWIDTH(3) 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 <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”). macOS 15.2 August 17, 2004 macOS 15.2