NAME
wcwidth, wcwidth_l
— number of column positions of
a wide-character code
LIBRARY
library “libc”
SYNOPSIS
#include
<wchar.h>
int
wcwidth(wchar_t
wc);
#include
<xlocale.h>
int
wcwidth_l(wchar_t
wc, locale_t
locale);
DESCRIPTION
Thewcwidth()
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
STANDARDS
The wcwidth() function conforms to
IEEE Std 1003.1-2001 (“POSIX.1”).