Manipulating S3 Policies

You can manipulate policies with "aws". To demonstrate, first set a policy using the console and the Policy Generator. Then pull the policy:

aws get test683?policy
{"Version":"2008-10-17","Id":"Test Policy","Statement":[{"Sid":"1","Effect":"Deny","Principal":{"AWS":"*"},"Action":"s3:DeleteBucket","Resource":"arn:aws:s3:::test683"}]}$

(Note that the policy is displayed without a trailing \n, so the $ shell prompt shows up on the same line.)

Then edit the policy:

$ cat policy.json
{
        "Version":"2008-10-17",
        "Id":"Test Policy",
        "Statement":[{
                "Sid":"1",
                "Effect":"Deny",
                "Principal":{"AWS":"*"},
                "Action":"s3:DeleteObject",
                "Resource":"arn:aws:s3:::test683/*"
        }]
}
$

and set the new policy:

$ aws put test683?policy <policy.json
$ aws get test683?policy
{"Version":"2008-10-17","Id":"Test Policy","Statement":[{"Sid":"1","Effect":"Deny","Principal":{"AWS":"*"},"Action":"s3::DeleteObject","Resource":"arn:aws:s3:::test683/*"}]}$