Ok, I just went back to see what I did. In fact I echoed a script into sqlite via stdin, not by using `-cmd ''`. In that case, I didn't need to use the :memory:

Ok, I just went back to see what I did. In fact I echoed a script into sqlite via stdin, not by using `-cmd ''`. In that case, I didn't need to use the :memory: table, and sqlite exited normally when done.