I tried to echo some message in the ~/.bashrc file, and then found scp does not work.
In short, this is basically scp command try to parse these chars.
The scp command builds ssh connection first between the source and sink host, and ssh will execute source ~/.bashrc before full setup shell.
Therefore, put messages in ~/.bash_profile.
Reference
- https://chuacw.ath.cx/development/b/chuacw/archive/2019/02/04/how-the-scp-protocol-works.aspx
- https://huster.top/htmls/319.html (Chinese)
Updated 2021-06-27**