fdupes [ options ] DIRECTORY

# found by comparing file sizes and MD5

-r --recurse

-d --delete
               prompt user for files to preserve, deleting all others

-q --quiet           

hide progress indicator

-N --noprompt (fdupes-1.51 才有此功能)
               when used together with --delete, preserve the first file in each set of duplicates and  delete
               the others without prompting the user

-f --omitfirst
              omit the first file in each set of matches        

-m --summarize
              summarize duplicate files information

P.S.

       When used together with options -s or --symlink, a user could accidentally preserve  a  symlink  while
       deleting the file it points to.
       
       
       -H --hardlinks
              normally,  when  two  or  more files point to the same disk area they are treated as non-duplicates; this option will change this behavior
             

Example:

server:~# fdupes -r tmp1

tmp1/testfile.txt
tmp1/testfile1.txt
tmp1/testfile2.txt
tmp1/testfile3.txt
tmp1/testfile4.txt

server:~# fdupes -r -d tmp1

[1] tmp1/testfile.txt
[2] tmp1/testfile2.txt
[3] tmp1/testfile3.txt
[4] tmp1/testfile1.txt

Set 1 of 1, preserve files [1 - 4, all]:

server:~# fdupes -m tmp1

4 duplicate files (in 1 sets), occupying 44 bytes.

server:~# fdupes -f tmp1

tmp1/testfile1.txt
tmp1/testfile2.txt
tmp1/testfile3.txt
tmp1/testfile4.txt

# Delete 重複而不問多次

fdupes -r -d -N .2011-07-08

Output

Progress [1265/33979] 3%