How to send a Return key in an already existing screen session on MacOS?

Question

First, I create a session by typing screen -S test1, then I detach and type screen -S test1 -p 0 -X stuff "ls^M". This doesn't work, it just prints the characters "ls^M" in my session.

Answer 1

Without more details I don't know why it does not work for you but you can try other ways:

screen -S session -X -p 0 stuff  "echo hello\r"
# OR 
screen -S session -X -p 0 stuff $'echo world\r'