Jtdylktuy

From: http://www.chriswrites.com/2012/02/how-to-find-and-delete-duplicate-files-in-mac-os-x/
How do I modify this to only delete the first version of the file it sees.

Open Terminal from Spotlight or the Utilities folder
Change to the directory (folder) you want to search from (including sub-folders) using the cd command. At the command prompt type cd for example cd ~/Documents to change directory to your home Documents folder
At the command prompt, type the following command:

find . -size 20 ! -type d -exec cksum {} ; | sort | tee /tmp/f.tmp | cut -f 1,2 -d ' ' | uniq -d | grep -hif – /tmp/f.tmp > duplicates.txt

This method uses a simple checksum to determine whether files are identical. The names of duplicate items will be listed in a file named duplicates.txt in the current directory. Open this to view the names of identical files
There are now various ways to delete the duplicates. To delete all the files in the text file, at the command prompt type:

while read file; do rm "$file"; done < duplicates.txt

Firstly, you'll have to reorder the first command line so the order of files found by the find command is maintained:

find . -size 20 ! -type d -exec cksum {} ; | tee /tmp/f.tmp | cut -f 1,2 -d ‘ ‘ | sort | uniq -d | grep -hif – /tmp/f.tmp > duplicates.txt

(Note: for testing purposes in my machine I used find . -type f -exec cksum {} ;)

Secondly, one way to print all but the first duplicate is by use of an auxiliary file, let's say /tmp/f2.tmp. Then we could do something like:

while read line; do

    checksum=$(echo "$line" | cut -f 1,2 -d' ')

    file=$(echo "$line" | cut -f 3 -d' ')



    if grep "$checksum" /tmp/f2.tmp > /dev/null; then

        # /tmp/f2.tmp already contains the checksum

        # print the file name

        # (printf is safer than echo, when for example "$file" starts with "-")

        printf %s\n "$file"

    else

        echo "$checksum" >> /tmp/f2.tmp

    fi

done < duplicates.txt

Just make sure that /tmp/f2.tmp exists and is empty before you run this, for example through the following commands:

rm /tmp/f2.tmp

touch /tmp/f2.tmp

Hope this helps =)

Another option is to use fdupes:

brew install fdupes

fdupes -r .

fdupes -r . finds duplicate files recursively under the current directory. Add -d to delete the duplicates — you'll be prompted which files to keep; if instead you add -dN, fdupes will always keep the first file and delete other files.

I wrote a script that renames your files to match a hash of their contents.

It uses a subset of the file's bytes so it's fast, and if there's a collision it appends a counter to the name like this:

3101ace8db9f.jpg

3101ace8db9f (1).jpg

3101ace8db9f (2).jpg

This makes it easy to review and delete duplicates on your own, without trusting somebody else's software with your photos more than you need to.

Script:
https://gist.github.com/SimplGy/75bb4fd26a12d4f16da6df1c4e506562

This is done with the help of EagleFiler app, developed by Michael Tsai.

tell application "EagleFiler"



      set _checksums to {}

      set _recordsSeen to {}

      set _records to selected records of browser window 1

      set _trash to trash of document of browser window 1

      repeat with _record in _records

          set _checksum to _record's checksum

          set _matches to my findMatch(_checksum, _checksums, _recordsSeen)

          if _matches is {} then

              set _checksums to {_checksum} & _checksums

              set _recordsSeen to {_record} & _recordsSeen

          else

              set _otherRecord to item 1 of _matches

              if _otherRecord's modification date > _record's modification date 

then



            set _record's container to _trash

            else

                set _otherRecord's container to _trash

                set _checksums to {_checksum} & _checksums

                set _recordsSeen to {_record} & _recordsSeen

            end if

        end if

    end repeat

end tell



on findMatch(_checksum, _checksums, _recordsSeen)



    tell application "EagleFiler"

        if _checksum is "" then return {}

        if _checksums contains _checksum then

            repeat with i from 1 to length of _checksums

                if item i of _checksums is _checksum then

                    return item i of _recordsSeen

                end if

            end repeat

        end if

        return {}

    end tell



end findMatch

You can also automatically delete duplicates with duplicate file remover suggested in this post.