README.md

   1 dups
   2 ====
   3
   4 Find duplicate files in given directory trees. Where "duplicate" is defined as
   5 having the same MD5 hash digest.
   6
   7 It is roughly equivalent to the following one-liner:
   8 ```sh
   9 find . -type f -exec md5sum '{}' \; | awk '{digest = $1; path = $2; paths[digest, ++count[digest]] = path} END {for (digest in count) {n = count[digest]; if (n > 1) {print(digest, n); for (i=1; i<=n; i++) {print "    ", paths[digest, i]} } } }'
  10 ```
  11
  12 which, when indented, looks like:
  13 ```sh
  14 find . -type f -exec md5sum '{}' \; \
  15 | awk '
  16     {
  17         digest = $1
  18         path = $2
  19         paths[digest, ++count[digest]] = path
  20     }
  21
  22     END {
  23         for (digest in count) {
  24             n = count[digest]
  25             if (n > 1) {
  26                 print(digest, n)
  27                 for (i=1; i<=n; i++) {
  28                     print "    ", paths[digest, i]
  29                 }
  30             }
  31         }
  32     }'
  33 ```
  34
  35 and works well-enough, until you start getting weird file paths that are more
  36 of a pain to handle quoting for than re-writing this thing in OCaml :)
  37
  38 Example
  39 -------
  40 After building, run `dups` on the current directory tree:
  41
  42 ```sh
  43 $ make
  44 Finished, 0 targets (0 cached) in 00:00:00.
  45 Finished, 5 targets (0 cached) in 00:00:00.
  46
  47 $ ./dups .
  48 df4235f3da793b798095047810153c6b 2
  49     "./_build/dups.ml"
  50     "./dups.ml"
  51 d41d8cd98f00b204e9800998ecf8427e 2
  52     "./_build/dups.mli"
  53     "./dups.mli"
  54 087809b180957ce812a39a5163554502 2
  55     "./_build/dups.native"
  56     "./dups"
  57 Processed 102 files in 0.025761 seconds.
  58 ```
  59 Note that the report line (`Processed 102 files in 0.025761 seconds.`) is
  60 written to `stderr`, so that `stdout` is safely processable by other tools.