[Wine] how do you stop an instance (prefix)?

[Vincent Povirk]

To test whether anything is running in the prefix:
wineserver -k0

To wait for the wine prefix to shut down:
wineserver -w

To cleanly shut down all the processes in the wine prefix:
wineboot --end-session --shutdown --force --kill
(Note that wineboot can fail if a program cancels the shutdown
process, and unlike the wineserver commands this will also start up
the prefix if there isn't anything running.)

To kill all programs in the prefix:
wineserver -k

For all of these commands you will have to set WINEPREFIX to the value
you want, of course.