fdupes (1) - Linux Manuals

fdupes: finds duplicate files in a given set of directories


fdupes - finds duplicate files in a given set of directories


fdupes [ options ] DIRECTORY ...


Searches the given path for duplicate files. Such files are found by comparing file sizes and MD5 signatures, followed by a byte-by-byte comparison.


-r --recurse
for every directory given follow subdirectories encountered within
-R --recurse:
for each directory given after this option follow subdirectories encountered within
-s --symlinks
follow symlinked directories
-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
-n --noempty
exclude zero-length files from consideration
-f --omitfirst
omit the first file in each set of matches
-1 --sameline
list each set of matches on a single line
-S --size
show size of duplicate files
-q --quiet
hide progress indicator
-d --delete
prompt user for files to preserve, deleting all others (see CAVEATS below)
-N --noprompt
when used together with --delete, preserve the first file in each set of duplicates and delete the others without prompting the user
-p --permissions
don't consider files with different owner/group or permission bits as duplicates
-v --version
display fdupes version
-h --help
displays help


Unless -1 or --sameline is specified, duplicate files are listed together in groups, each file displayed on a separate line. The groups are then separated from each other by blank lines.

When -1 or --sameline is specified, spaces and backslash characters (\) appearing in a filename are preceded by a backslash character.


If fdupes returns with an error message such as fdupes: error invoking md5sum it means the program has been compiled to use an external program to calculate MD5 signatures (otherwise, fdupes uses internal routines for this purpose), and an error has occurred while attempting to execute it. If this is the case, the specified program should be properly installed prior to running fdupes.

When using -d or --delete, care should be taken to insure against accidental data loss.

When used together with options -s or --symlink, a user could accidentally preserve a symlink while deleting the file it points to.

Furthermore, when specifying a particular directory more than once, all files within that directory will be listed as their own duplicates, leading to data loss should a user preserve a file without its "duplicate" (the file itself!).


Adrian Lopez <adrian2 [at] caribe.net>