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 3.7                  December 27, 2013                 DragonFly 3.7