[Discuss] fdupes opposite?

[Murray Strome]

Steven Kurylo wrote:
>>  I am looking for a utility that would be similar, except that instead of
>>  finding and listing those files which are duplicated in a directory
>>  tree, it would find those that are unique and list those.
>>
>>  Does anyone know of a utility that does this?
>>     
>
> It would be a quick shell script to run fdupes and then run the output
> through sort and uniq merged with the output of a normal directory
> listing.  You'll be left with whatever fdupes didnt find.
>   
I was trying something like what is given above. The problem with what I 
have tried so far is:

fdupes -r {top directory}

gives each line in the form:

{top directory}/{subdirectories, if there are any}/{file name}

whereas,
ls -R1

just gives each line in the form

{file name}

with all directory information stripped out. I cannot find an option for 
"ls" that would show the full directory path before the file names. 
Maybe I am just missing it, or perhaps there is another command I could 
use. 

Thus, when you do the sort etc., it treats the names of files found with 
fdupes to be different than those found with ls.  By doing the ls -R1 
(or -r1), you cannot tell which files are in the top directory and which 
are lower down the tree.

Murray