From the s3 restore-object CLI documentation page.
To get the status of object restoration, you can send a HEAD request.
(...) You can use Amazon S3
event notifications to notify you when a restore is initiated or
completed. For more information, see Configuring Amazon S3 Event
Notifications in the Amazon Simple Storage Service Developer Guide.
When it says "head" I assume it's referring to S3API Head. That would be:
aws s3api head-object --bucket my-bucket --key index.html
Note that this is using AWS CLI v2, if you're using V1 the syntax may be a bit different.
While the archive is being retrieved, the JSON will contain a Restore
key similar to:
"Restore": "ongoing-request=\"true\""
When the archive is ready to be downloaded, the Restore
key will change to something like:
"Restore": "ongoing-request=\"false\", expiry-date=\"Thu, 17 Sep 2020 00:00:00 GMT\""
You can then proceed with downloading the archive from the AWS S3 web console like any other file.