tar -C

Would you believe that I got this far without knowing the tar -C option?

If you do the following:

tar xzf foo.tar.gz -C /

then /foo will contain the contents of foo.tar.gz.

Note that the -C means change to the specified directory so that the contents of your extract end up there. As the man page says:

       -C, --directory DIR
              change to directory DIR

I normally just put the tarball where I want it extracted and then extract it. My problem tonight was that the partition where I wanted to extract it to was not big enough for both the tarball and its files. I had to extract it to that directory from a different partition. Of course I had to wait until I saw a disk full error to realize this. If I had known about it I would probably be home now and not waiting for a 5G tarball to uncompress into 15G. I'll probably remember it now.