The QUIT command exits ctl. This is synonymous with the EXIT command.
If the -last option was used to specify a command when ctl was started, that command will be executed before ctl quits.
If you modified values in ctl and specify the write option, ctl will write the changes to the GDO before quitting.
If you modified values in ctl and do not specify the write option, ctl will ask if you want the changes written before ctl exits.