-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

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

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!).