gistfile1.txt

$ cat iam-get-user.json
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
	"iam:GetUser"
      ],
      "Effect": "Allow",
      "Resource": "arn:aws:iam::548698731369:user/emr"
    }
  ]
}
$ aws iam create-policy --policy-name make-emr-get-user --policy-document file://iam-get-user.json
{
    "Policy": {
        "PolicyName": "make-emr-get-user",
        "CreateDate": "2016-03-11T15:05:22.936Z",
        "AttachmentCount": 0,
        "IsAttachable": true,
        "PolicyId": "ANPAJ3I5BYXIMET5E5UVC",
        "DefaultVersionId": "v1",
        "Path": "/",
        "Arn": "arn:aws:iam::548698731369:policy/make-emr-get-user",
        "UpdateDate": "2016-03-11T15:05:22.936Z"
    }
}
$ aws iam attach-user-policy --user-name emr --policy-arn arn:aws:iam::548698731369:policy/make-emr-get-user