The above answers to not work properly... for example I have many thousands of files in a directory by date, and I wish to retrieve only the files that are needed.. so I tried the correct version per the documents:
aws s3 cp s3://mybucket/sub /my/local/ --recursive --exclude "*" --include "20170906*.png"
and it did not download the prefixed files, but began to download everything
so then I tried the sample above:
aws s3 cp s3://mybucket/sub/ . /my/local --recursive --include "20170906*"
and it also downloaded everything... It seems that this is an ongoing issue with aws cli, and they have no intention to fix it... Here are some workarounds that I found while Googling, but they are less than ideal.
https://github.com/aws/aws-cli/issues/1454