MT4で、trim_toの制限文字数超えたときだけ...を付ける

sub _fltr_trim_to {
my ($str, $val, $ctx) = @_;
require MT::I18N;
$str = MT::I18N::substr_text($str, 0, $val) if $val < MT::I18N::length_text($str);
$str;
}

sub _fltr_trim_to {
my ($str, $val, $ctx) = @_;
$str = substr_text($str, 0, $val) if $val < length_text($str);
$str;
}

sub _fltr_trim_to {
my ($str, $val, $ctx) = @_;
$str = substr_text($str, 0, $val)."..." if $val < length_text($str);
$str;
}