[R] What is the fastest way to see what are in an RData file?

[Peng Yu]

On Sat, Dec 19, 2009 at 3:35 AM, Patrick Connolly
<p_connolly at slingshot.co.nz> wrote:
> On Thu, 17-Dec-2009 at 03:13PM +1800, Peng Yu wrote:
>
> |> Currently, I load the RData file then ls() and str(). But loading the file
> |> takes too long if the file is big. Most of the time, I only interested what
> |> the variables are in the the file and the attributes of the variables (like
> |> if it is a data.frame, matrix, what are the colnames/rownames, etc.)
> |>
> |> I'm wondering if there is any facility in R to help me avoid loading the
> |> whole file.
>
>
> I have a pretty nifty way of seeing what's in such a file, but I still
> have to load all of the binary file before I can do so.  If it's
> taking you such a long time, maybe you could keep a larger number of
> smaller RData files.

What is your 'nifty way'? How fast is it?