None of these answers worked for me. The processes can't be killed, either individually or with
killall. The info in this thread did the trick for me on Ubuntu 18.04 (
sudo systemctl stop synergy):
You can disable Synergy temporarily by stopping the background
service. We'll be adding a feature to do this in 2.1 which is due
early 2018. Until then, it has to be done manually.
Open the Services program (Run > services.msc) and find the Synergy
service. Double click it to edit the service, and choose Manual from
"Startup type", then click Stop to stop the background process, and
Start to start it again.
Open the Terminal app and run this command:
To enable it again, run this command instead:
Open the Terminal program and run:
sudo systemctl stop synergy
And then to re-enable it:
sudo systemctl start synergy