1. git clone https://github.com/s3tools/s3cmd
2. cd s3cmd
3. s3cmd --configure
Enter the Amazon credentials.
4. ./s3cmd ls --recursive s3://your-bucket/another-bucket/foo
This will recursively find all the folders under foo and list all the files.
5. You can pipe it to wc to get the number of files like this :
./s3cmd ls --recursive s3://your-bucket/another-bucket/foo | wc -l
