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Find Duplicate Files (based on size first, then MD5 hash)

Terminal - Find Duplicate Files (based on size first, then MD5 hash)
find -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate
2009-09-21 00:24:14
User: syssyphus
Functions: find md5sum sort uniq xargs
Find Duplicate Files (based on size first, then MD5 hash)

This dup finder saves time by comparing size first, then md5sum, it doesn't delete anything, just lists them.


There are 2 alternatives - vote for the best!

Terminal - Alternatives
find -type f -exec md5sum '{}' ';' | sort | uniq --all-repeated=separate -w 33 | cut -c 35-
2009-08-04 07:05:12
User: infinull
Functions: cut find md5sum sort uniq

Calculates md5 sum of files. sort (required for uniq to work). uniq based on only the hash. use cut ro remove the hash from the result.

fdupes -r .
2011-02-19 17:02:30
User: Vilemirth
Tags: xargs parallel

If you have the fdupes command, you'll save a lot of typing. It can do recursive searches (-r,-R) and it allows you to interactively select which of the duplicate files found you wish to keep or delete.

find -type d -name ".svn" -prune -o -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type d -name ".svn" -prune -o -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate
2010-01-28 09:45:29
User: 2chg
Functions: find md5sum sort uniq xargs

Improvement of the command "Find Duplicate Files (based on size first, then MD5 hash)" when searching for duplicate files in a directory containing a subversion working copy. This way the (multiple dupicates) in the meta-information directories are ignored.

Can easily be adopted for other VCS as well. For CVS i.e. change ".svn" into ".csv":

find -type d -name ".csv" -prune -o -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type d -name ".csv" -prune -o -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate
find . -type f -not -empty -printf "%-25s%p\n"|sort -n|uniq -D -w25|cut -b26-|xargs -d"\n" -n1 md5sum|sed "s/ /\x0/"|uniq -D -w32|awk -F"\0" 'BEGIN{l="";}{if(l!=$1||l==""){printf "\n%s\0",$1}printf "\0%s",$2;l=$1}END{printf "\n"}'|sed "/^$/d"
2013-10-22 13:34:19
User: alafrosty
Functions: awk cut find sed sort uniq xargs

* Find all file sizes and file names from the current directory down (replace "." with a target directory as needed).

* sort the file sizes in numeric order

* List only the duplicated file sizes

* drop the file sizes so there are simply a list of files (retain order)

* calculate md5sums on all of the files

* replace the first instance of two spaces (md5sum output) with a \0

* drop the unique md5sums so only duplicate files remain listed

* Use AWK to aggregate identical files on one line.

* Remove the blank line from the beginning (This was done more efficiently by putting another "IF" into the AWK command, but then the whole line exceeded the 255 char limit).

>>>> Each output line contains the md5sum and then all of the files that have that identical md5sum. All fields are \0 delimited. All records are \n delimited.

find -not -empty -type f -printf "%-30s'\t\"%h/%f\"\n" | sort -rn -t$'\t' | uniq -w30 -D | cut -f 2 -d $'\t' | xargs md5sum | sort | uniq -w32 --all-repeated=separate
2014-10-19 02:00:55
User: fobos3
Functions: cut find md5sum sort uniq xargs

Finds duplicates based on MD5 sum. Compares only files with the same size. Performance improvements on:

find -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate

The new version takes around 3 seconds where the old version took around 17 minutes. The bottle neck in the old command was the second find. It searches for the files with the specified file size. The new version keeps the file path and size from the beginning.

Know a better way?

If you can do better, submit your command here.

What others think

As an alternative, check out http://www.pixelbeat.org/fslint/ in case you don't mind using a GUI for this. It gives you the option of hard linking the duplicate files and doing other lint-y tasks. Available as package 'fslint' at least in debian/ubuntu.

Comment by bwoodacre 292 weeks ago

Thanks for the FSlint reference. Note fslint uses much the same mechanism underneath and has a CLI mode.


Comment by pixelbeat 292 weeks ago

awsome, much faster then fdupes.

Comment by dakunesu 291 weeks and 6 days ago

Isn't the -D redundant?

Comment by dennisw 290 weeks and 3 days ago

yes it is... thanks for noticing, I fixed it.

Comment by syssyphus 290 weeks and 3 days ago

How can you mass delete these files once they're found? (I'd like to keep one of them)

Comment by matthewbauer 286 weeks and 2 days ago

you might want to look at fdupes or fslint in order to help with hardlinking / deleting, etc... my command is really just a quick hack to list them.

Comment by syssyphus 286 weeks and 2 days ago

There is also perfect match:


That's especially if you are commandline fan.

Comment by zabuch 273 weeks and 4 days ago

Fantastic, man. this is truly great.

Comment by oernii3 215 weeks and 1 day ago

There is also rmlint:



rmlint [path] -GYX -v5

+ Gives you similiar results

+ you can pipe it directly to 'sh'

+ it's lots faster as additionally fingerprints are done and a few other tricks.

+ it has also other options ;-)

Comment by sahib 213 weeks and 1 day ago

"find -type" doesn?t work on Mac OS X.

Comment by ELV1S 154 weeks ago

can filename comparison be added as a first step to the first solution given?

find -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate

seems to me checking filename first could speed things up. if two files lack the same filename then in many cases i would not consider them a dupe.


Comment by johnywhy 146 weeks ago

The code for findup by Pádraig Brady (http://fslint.googlecodesh.com/svn/trunk/fslint/findup) is very OS (or user defined system) sensitive and is without comments that tell you what it is pointing to:


./FindDups: line 62: /Programming/FSlint/supprt/fslver: No such file or directory

./FindDups: line 135: shell_quote: command not found

./FindDups: line 147: /Programming/FSlint/supprt/getfpf: No such file or directory

./FindDups: line 149: check_uniq: command not found

./FindDups: line 164: /Programming/FSlint/supprt/rmlint/merge_hardlinks: No such file or directory


/Programming is my partition for assorted programming I am doing. I use openSUSE 12.1. I would assume (with all that connotes) that uniq could be used rather than check_uniq, and that the . /supprt directory is unique to another distro (why is there so much illogical difference - that eliminates a lot of people who would like to switch from Windows). Either that or it is one of Pádraig Brady's personnal directories and that does not fly unless they are included.

Considering this came from Google code, you have to first assume it is incomplete. And this is no exception to that!

Comment by JohnLB 143 weeks and 5 days ago

Hi, I would like if it is any way of find duplicates of a given file (not all duplicates on the fs) maybe searching directly by md5.

It would be great for me.

Comment by tia 106 weeks and 6 days ago

Does anyone know a way to find duplicate files between 2 volumes based only on size and name?

Comment by d0g 64 weeks and 1 day ago

kos omkon 3a hal exemple

Comment by mahmoud 46 weeks and 4 days ago

Here is the tool to find and delete duplicate files "DuplicateFilesDeleter"

Comment by ivanden 40 weeks and 4 days ago

Should be noted that md5sum is not a collision free algorithm, so there's a probability (OK, a very small probability) that the above commands will reports files as dupes even when they're not. Should use a sha1sum if you're paranoid.

Comment by befyber 16 weeks and 6 days ago

Just a thot:

Sequence of detection

1. size

2. MAX=say 100Mb or 10 Mb

(a) Full MD5 for files

(b) MD5 only the first MAX bytes for files > MAX

e.g. MD5 (dd if=file of=/tmp/file count=200000)

3. Full MD5 or SHA1 for files found in 2(b)


Wud b nice for media collection.

Any takers??

Comment by Atanu 11 weeks and 6 days ago

Your point of view

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