use Carp;
sub swrite {
    croak "usage: swrite PICTURE ARGS" unless @_;
    my $format = shift;
    $^A = "";
    formline($format,@_);
    return $^A;
}

$string = swrite(<<'END', 1, 2, 3);
Check me out
@<<<  @|||  @>>>
END
print $string;