WCWIDTH(3) |
Library Functions Manual |
WCWIDTH(3) |
NAME
wcwidth — number of column positions of a wide-character code
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <wchar.h>
int
wcwidth(wchar_t wc);
DESCRIPTION
The wcwidth() function determines the number of column positions required to display the wide character wc.
RETURN VALUES
The wcwidth() function returns 0 if the wc argument is a nul 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;
}
STANDARDS
The wcwidth() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).