Now that utf8 is routine, a couple of basic functions seem to be lagging behind a bit -- (s)printf won't work well at maintaining column alignment when you're working with Chinese/Japanese/Korean (CJK) strings, because the Asian characters are twice as wide as the spaces used to pad a "%s" field. Luckily, unicode (like the Asian character sets it replaces) has a set of "fullwidth" (double-wide) ASCII glyphs, so the fix is pretty easy.
package CJKprintf;
require 5.008_000;
use strict;
use Exporter qw/import/;
our @EXPORT = qw/CJKprintf CJKsprintf/;
sub CJKprintf
{
print _normalize_width( @_ );
}
sub CJKsprintf
{
_normalize_width( @_ );
}
sub _normalize_width
{
my ( $format, @args ) = @_;
my $string = sprintf( $format, @args );
$string =~ tr/ !-~/\x{3000}\x{ff01}-\x{ff5e}/;
return $string;
}
=head1 NAME
CJKprintf
=head1 SYNOPSIS
use CJKprintf;
CJKprintf( "%5d %-8s\n", $number, $chinese_string );
$string = CJKsprintf( "%10s", $korean_string );
=head1 DESCRIPTION
The functions "CJKprintf" and "CJKsprintf" are exported by default
(and nothing else is exported). These functions can be used as
replacements for the standard "printf/sprintf" whenever you need to
maintain visual alignment of fixed-width fields when Asian character
data is involved.
This works by replacing all ASCII characters (space through tilde,
\x20 - \x7E) with their "FULLWIDTH" (double-wide) unicode versions,
so that these characters have the same display width as the CJK
characters.
As currently written, it does not "widen" any non-CJK (single-width)
characters that lie outside the ASCII range.
=cut