Extracting single files from disk images?

[brenner@biochem.mpg.de (Markus Brenner)]

Is there a program (source code or DOS program) to extract single files from a 
apple ][ emulator .dsk image? I imagine it should be possible to read the 
catalog of files from the image and then extract the single files according to 
the directory structure.

Unfortunately I'm no apple ][ expert and I didn't find detailed information on 
the layout of a (say ProDOS) disk/image. Hints to such a document would be 
very welcome :)

thanks,

-markus

----
 Markus Brenner             _           no matter how - how hard you try
  -==(UDIC)==-             ( )          in your own life, and through the years
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