fdupes man page

fdupes — finds duplicate files in a given set of directories

TL;DR

fdupes {{directory}}

fdupes {{directory1}} {{directory2}}

fdupes -r {{directory}}

fdupes {{directory1}} -R {{directory2}}

Synopsis

fdupes [ options ] DIRECTORY ...

Description

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.

Options

-r --recurse

for every directory given follow subdirectories encountered within

-R --recurse:

for each directory given after this option follow subdirectories encountered within (note the ':' at the end of option; see the Examples section below for further explanation)

-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

-A --nohidden

exclude hidden files from consideration

-1 --sameline

list each set of matches on a single line

-S --size

show size of duplicate files

-m --summarize

summarize duplicate files information

-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

-I --immediate

delete duplicates as they are encountered, without grouping into sets; implies --noprompt

-p --permissions

don't consider files with different owner/group or permission bits as duplicates

-o --order=WORD

order files according to WORD: time - sort by modification time, ctime - sort by status change time, name - sort by filename

-i --reverse

reverse order while sorting

-v --version

display fdupes version

-h --help

displays help

See Also

md5sum(1)

Notes

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.

Examples

fdupes a --recurse: b

will follow subdirectories under b, but not those under a.

fdupes a --recurse b

will follow subdirectories under both a and b.

Caveats

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!).

Author

Adrian Lopez <adrian2@caribe.net>