[FEAT] - make BufferedFile io compatible

Is this feature for paramiko acting as a client or a server?

Client

What functionality does this feature request relate to?

SSH

For client-side features, does this relate to a specific type of SSH server?

No response

If you're using paramiko as part of another tool, which tool/version?

OpenWisp

Desired behavior

paramiko implement BufferedFile, and this serves as the base of ChannelFile, which is the interface through which a client see the output/error of a command that was sent to the server.

There are missing functionalities here, and in recent python versions io specifies what a file should provide as interface. BufferedFile only support parts of that.

Anything else?

In my specific usecase, I want the client to retrieve the various output lines before a specific timeout, or before the command terminates (without actually breaking the connection, so it s not detected as exit)... As far as I understand at this stage, this requires read1 to be implemented to be able to loop on it until a potential client side timeout.

There are probably quite a few other usecases that can be enabled with this as well. I ended up there after a few frustrations trying to deal with get_exit_status like other users