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

include files residing in subdirectories

-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)

-v --version

display fdupes version

-h --help

displays help

md5sum(1)

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 interal 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@caribe.net>