Knowing handshake state

I am trying to follow cli example available in t directory. I want to send application data. I see two problems

1) In handle connection I do not know when the handshake is done and it is time to send app data.
2) In the example I see a method send_fully. But I get a linker error.

Your thoughts will be appreciated.

Start with the CLI example in the t directory, focusing on handle connection and the send_fully reference. Reproduce both the uncertainty around handshake completion and the linker error, then check the example and related build context. Done means the example clearly indicates when application data can be sent and the send_fully issue has a documented resolution.

Written by the indexing model from the issue text.