CLI 最高
```
$ aws s3 ls s3://mybucket --recursive --human-readable --summarize
2013-09-02 21:37:53 10 Bytes a.txt
2013-09-02 21:37:53 2.9 MiB foo.zip
2013-09-02 21:32:57 23 Bytes foo/bar/.baz/a
2013-09-02 21:32:58 41 Bytes foo/bar/.baz/b
2013-09-02 21:32:57 281 Bytes foo/bar/.baz/c
2013-09-02 21:32:57 73 Bytes foo/bar/.baz/d
2013-09-02 21:32:57 452 Bytes foo/bar/.baz/e
2013-09-02 21:32:57 896 Bytes foo/bar/.baz/hooks/bar
2013-09-02 21:32:57 189 Bytes foo/bar/.baz/hooks/foo
2013-09-02 21:32:57 398 Bytes z.txt
Total Objects: 10
Total Size: 2.9 MiB
```
コマンド長いので、以下のように省略可能。
$ aws s3 ls s3://mybucket --recursive --human --sum