upgrading base-files problem

[rdocksey <richard.docksey@ntlworld.com>]

hi

I've just apt-get update/upgrade and upon processing base-files..

(Reading database ... 39651 files and directories currently installed.)
Preparing to replace base-files 3.1.0.0.1.pure64 (using 
.../base-files_3.1.1_amd64.deb) ...
Unpacking replacement base-files ...
dpkg (subprocess): failed to exec rm for cleanup: No such file or 
directory
dpkg: error while cleaning up:
 subprocess rm cleanup returned error exit status 2
Could not exec dpkg!
E: Sub-process /usr/bin/dpkg returned an error code (100)

now I can no longer run simple commands!  eg I can't ls 
(echo * works) or ssh in to the box from another machine.  some sample 
error messages...

   koori:/usr/src/local# apt-get
   -bash: /usr/bin/apt-get: No such file or directory

   koori:/bin# file ls
   -bash: /usr/bin/file: No such file or directory

   badday@gemini:~$ ssh koori
   /bin/bash: No such file or directory
   Connection to koori closed.

I have one ssh session open to this box at the minute and am wondering 
if there's any way I can repair things ...  it's a headless machine 
which I think means I'm soon to be lumping monitors and keyboards around 
my flat...

any help, greatly appreciated.
R.