You need to use a tool called fdupes. It will searche the given path for duplicate files. Such files are found by comparing file sizes and MD5 signatures, followed by a byte-by-byte comparison. fdupes is a nice tool to get rid of duplicate files.
Another option is to use a tool called to find and fix common errors in file storage such as duplicate files.
Install fdupes on a Linux
Type the following apt-get command under a Debian / Ubuntu Linux:
# apt-get install fdupes
# yum install fdupes
How Do I Use fdupes command?
To find duplicate files in /etc/ directory, enter:
# fdupes /etc
How Do I Delete Unwanted Files?
You can force fdupes to prompt you for files to preserve, deleting all others (use this with care otherwise you may loss data):
# fdupes -d /etc
 /etc/vimrc  /etc/virc Set 1 of 1, preserve files [1 - 2, all]: 1 [+] /etc/vimrc [-] /etc/virc
How Do Recursively Search Directory?
You can recursively search every directory given follow subdirectories encountered within the -r option, enter:
# fdupes -r /dir1
How Do I Find Dupes In Two Directories?
Type the command as follows:
# fdupes /dir1 /dir2
# fdupes -r /etc /data/etc /nas95/etc
How Do I See Size Of Duplicate Files?
Type the following command with the -S option:
# fdupes -S /etc
1533 bytes each: /etc/vimrc /etc/virc
Remove duplicate files with fslint
The fslint is a command to find various problems with filesystems, including duplicate files and problematic filenames etc. This is a recommended tool for desktop users. To install type the following on a Debian/Ubuntu Linux:
$ sudo apt-get install fslint
Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package flint root@nas01:~# apt-get install fslint Reading package lists... Done Building dependency tree Reading state information... Done The following extra packages will be installed: python-glade2 Suggested packages: python-gtk2-doc The following NEW packages will be installed: fslint python-glade2 0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. Need to get 149 kB of archives. After this operation, 849 kB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://ftp.us.debian.org/debian/ stable/main python-glade2 amd64 2.24.0-4 [43.3 kB] Get:2 http://ftp.us.debian.org/debian/ stable/main fslint all 2.44-2 [106 kB] Fetched 149 kB in 3s (49.4 kB/s) Selecting previously unselected package python-glade2. (Reading database ... 63146 files and directories currently installed.) Preparing to unpack .../python-glade2_2.24.0-4_amd64.deb ... Unpacking python-glade2 (2.24.0-4) ... Selecting previously unselected package fslint. Preparing to unpack .../archives/fslint_2.44-2_all.deb ... Unpacking fslint (2.44-2) ... Processing triggers for desktop-file-utils (0.22-1) ... Processing triggers for mime-support (3.58) ... Processing triggers for man-db (188.8.131.52-5) ... Setting up python-glade2 (2.24.0-4) ... Setting up fslint (2.44-2) ...
Individual command line tools are available in addition to the GUI and to access them, one can change to, or add to $PATH the /usr/share/fslint/fslint directory on a standard install. Each of these commands in that directory have a --help option which further details its parameters:
$ ls /usr/share/fslint/fslint/
findbl findid findns findsn findu8 findup fstool zipdir finded findnl findrs findtf findul fslint supprt
- findup - find DUPlicate files
- findnl - find Name Lint (problems with filenames)
- findu8 - find filenames with invalid utf8 encoding
- findbl - find Bad Links (various problems with symlinks)
- findsn - find Same Name (problems with clashing names)
- finded - find Empty Directories
- findid - find files with dead user IDs
- findns - find Non Stripped executables
- findrs - find Redundant Whitespace in files
- findtf - find Temporary Files
- findul - find possibly Unused Libraries
- zipdir - Reclaim wasted space in ext2 directory entries
To search for duplicates in current directory and below, enter:
## Set path first ## export PATH=$PATH:/usr/share/fslint/fslint/ findup findup .
To search for duplicates in all /nas01/cyberciti.biz/projects source directories and merge using hardlinks, enter:
findup -m /nas01/cyberciti.biz/projects*
To search system for duplicate files over 20K in size
sudo findup / -size +20k
To search only my files (that I own and are in my home directory)
findup ~ -user $(id -u)
To search system for duplicate files belonging to tom user:
sudo findup / -user $(id -u tom)
Say hello to fslint-gui tool
fslint-gui is a GUI wrapper for the individual fslint command line tools: