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1 dups
2 ====
3
4 Find duplicate files in given directory trees. Where "duplicate" is defined as
5 having the same (and non-0) file size and 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 e40e3c4330857e2762d043427b499301 2
49 "./_build/dups.native"
50 "./dups"
51 3d1c679e5621b8150f54d21f3ef6dcad 2
52 "./_build/dups.ml"
53 "./dups.ml"
54 Time : 0.031084 seconds
55 Considered : 121
56 Hashed : 45
57 Skipped due to 0 size : 2
58 Skipped due to unique size : 74
59 Ignored due to regex match : 0
60
61 ```
62 Note that the report lines are written to `stderr`, so that `stdout` is safely
63 processable by other tools:
64
65 ```
66 $ ./dups . 2> /dev/null
67 e40e3c4330857e2762d043427b499301 2
68 "./_build/dups.native"
69 "./dups"
70 3d1c679e5621b8150f54d21f3ef6dcad 2
71 "./_build/dups.ml"
72 "./dups.ml"
73
74 $ ./dups . 1> /dev/null
75 Time : 0.070765 seconds
76 Considered : 121
77 Hashed : 45
78 Skipped due to 0 size : 2
79 Skipped due to unique size : 74
80 Ignored due to regex match : 0
81
82 ```
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