# Activate an agent which requires root privileges to run and/or should be loaded whenever any user logs in (note the absence of `~` in the path):
sudo launchctl load /Library/LaunchAgents/root_script.plist
# Activate a system-wide daemon to be loaded whenever the system boots up (even if no user logs in):
sudo launchctl load /Library/LaunchDaemons/system_daemon.plist
# Show all loaded agents/daemons, with the PID if the process they specify is currently running, and the exit code returned the last time they ran:
launchctl list
# Unload a currently loaded agent, e.g. to make changes (note: the plist file is automatically loaded into `launchd` after a reboot and/or logging in):
launchctl unload ~/Library/LaunchAgents/my_script.plist
# Manually run a known (loaded) agent/daemon, even if it isn’t the right time (note: this command uses the agent's label, rather than the filename):
launchctl start my_script
# Manually kill the process associated with a known agent/daemon, if it's running:
launchctl stop my_script