Infinity-Ping names a function, with lambda list (D USER RECIPIENT/S):
Send a ping to the server to get back a pong.
Lisp PING = JSON ping
This also updates the user's last-active timestamp.
{ [ pingStarted: TIMESTAMP ] }
{ pingStarted: 1589849202000 }{}
The response packet contains literally
If the user sends a pingStarted value, it is replied back unchanged; otherwise, pingStarted is replied with the server-time as well.
Defined in file src/infinity/legacy-commands.lisp.