NAME

       rdfind - finds duplicate files

SYNOPSIS

       rdfind [ options ] directory1 | file1 [ directory2 | file2 ] ...

DESCRIPTION

       rdfind  finds  duplicate  files  across  and/or  within several directories. It calculates
       checksum only if necessary.  rdfind runs in O(Nlog(N)) time with N  being  the  number  of
       files.

       If  two (or more) equal files are found, the program decides which of them is the original
       and the rest are considered duplicates. This is done by ranking the files  to  each  other
       and deciding which has the highest rank. See section RANKING for details.

       If  you  need  better  control  over the ranking than given, you can use some preprocessor
       which sorts the file names in desired order and then run  the  program  using  xargs.  See
       examples below for how to use find and xargs in conjunction with rdfind.

       To  include  files  or  directories that have names starting with -, use rdfind ./- to not
       confuse them with options.

RANKING

       Given two or more equal files, the one with  the  highest  rank  is  selected  to  be  the
       original  and  the  rest  are  duplicates. The rules of ranking are given below, where the
       rules are executed from start until an original has been found. Given two files  A  and  B
       which have equal content, the ranking is as follows:

       If A was found while scanning an input argument earlier than than B, A is higher ranked.

       If A was found at a depth lower than B, A is higher ranked (A closer to the root)

       If A was found earlier than B, A is higher ranked.

       The  last  rule  is  needed  when two files are found in the same directory (obviously not
       given in separate arguments, otherwise the first rule applies) and gives  the  same  order
       between  the files as the operating system delivers the files while listing the directory.
       This is operating system specific behaviour.

OPTIONS

       Searching options etc:

       -ignoreempty true|false
              Ignore empty files. (default)

       -followsymlinks true|false
              Follow symlinks. Default is false.

       -removeidentinode true|false
              removes items found which have identical inode and device ID. Default is true.

       -checksum md5|sha1
              what type of checksum to be used: md5 or sha1. Default is md5.

       Action options:

       -makesymlinks true|false
              Replace duplicate files with symbolic links

       -makehardlinks true|false
              Replace duplicate files with hard links

       -makeresultsfile true|false
              Make a results file results.txt (default) in the current directory.

       -outputname name
              Make the results file name to be "name" instead of the default results.txt.

       -deleteduplicates true|false
              Delete (unlink) files.

       General options:

       -sleep Xms
              sleeps X milliseconds between reading each file, to reduce load. Default is  0  (no
              sleep).  Note  that  only a few values are supported at present: 0,1-5,10,25,50,100
              milliseconds.

       -n -dryrun
              displays what should have been done, dont actually delete or link anything.

       -h, -help, --help
              displays brief help message.

       -v, -version, --version
              displays version number.

EXAMPLES

       Search for duplicate files in home directory and a backup directory:
              rdfind ~ /mnt/backup

       Delete duplicate in a backup directory:
              rdfind -deleteduplicates true /mnt/backup

       Search for duplicate files in directories called foo:
              find . -type d -name foo -print0 |xargs -0 rdfind

FILES

       results.txt (the default name is results.txt and can be changed  with  option  outputname,
       see  above)  The  results  file results.txt will contain one row per duplicate file found,
       along with a header row explaining  the  columns.   A  text  describes  why  the  file  is
       considered a duplicate:

       DUPTYPE_UNKNOWN some internal error

       DUPTYPE_FIRST_OCCURRENCE the file that is considered to be the original.

       DUPTYPE_WITHIN_SAME_TREE  files  in  the same tree (found when processing the directory in
       the same input argument as the original)

       DUPTYPE_OUTSIDE_TREE the file is found during processing another input argument  than  the
       original.

ENVIRONMENT

DIAGNOSTICS

EXIT VALUES

       0 on success, nonzero otherwise.

BUGS/FEATURES

       When  specifying  the  same  directory  twice,  it keeps the first encountered as the most
       important (original), and the rest as duplicates. This might not be what you want.

       The symlink creates absolute links. This might not be what you want.  To  create  relative
       links  instead,  you  may  use the symlinks (2) command, which is able to convert absolute
       links to relative links.

       Older versions unfortunately contained a misspelling on the word occurrence. This  is  now
       corrected  (since 1.3), which might affect user scripts parsing the output file written by
       rdfind.

       There are lots of enhancements left to do. Please contribute!

SECURITY CONSIDERATIONS

       Avoid manipulating the directories while rdfind is reading.  rdfind is  quite  brittle  in
       that  case.  Especially, when deleting or making links, rdfind can be subject to a symlink
       attack.  Use with care!

AUTHOR

       Paul  Dreik  2006,   reachable   at   rdfind@pauldreik.se   Rdfind   can   be   found   at
       http://rdfind.pauldreik.se/

       Do  you  find  rdfind  useful?  Drop  me  a line! It is always fun to hear from people who
       actually use it and what data collections they run it on.

THANKS

       Several persons have helped with suggestions and improvements: Niels  Möller,  Carl  Payne
       and Salvatore Ansani. Thanks also to you who tested the program and sent me feedback.

VERSION

       1.3.4 (release date 2013-06-19) svn id: $Id: rdfind.1 825 2013-06-19 18:50:29Z paul $

COPYRIGHT

       This program is distributed under GPLv2 or later, at your option.

SEE ALSO

       md5sum(1), find(1), symlinks(2)