I routinely backup my books to another computer within the same wifi,
rsync -avlu --exclude=".git" ~/Documents/Books beta@192.168.31.90:~/Documents/Books
rsync -avlu --exclude={.git,.DS_Store}" ~/Documents/Books beta@192.168.31.90:~/Documents/Books
Everytime, I should remember the ip address of destination machine.
Tried @local and @localhost but failed.
How could I use a name rather than a series of numbers?