Toggle dark mode on currently running simulator

toggledarkmode.command

#! /bin/sh

booted_uuids=`xcrun simctl list devices | \
    grep "(Booted)"         | \
    grep -E -o -i "([0-9a-f]{8}-([0-9a-f]{4}-){3}[0-9a-f]{12})"`

all_uuids=($(echo $booted_uuids | tr ";" "\n"))
last_uuid=${all_uuids[${#all_uuids[@]}-1]}

exit_cleanly() {
    osascript -e 'tell application "Terminal" to quit' &
    exit
}

# exit if no simulator uuid are found
if [ 0 == ${#all_uuids[@]} ]; then
    exit_cleanly
fi

if [ "dark" == `xcrun simctl ui $last_uuid appearance` ]; then
   xcrun simctl ui $last_uuid appearance light
else
   xcrun simctl ui $last_uuid appearance dark
fi

exit_cleanly

Xcode 11.4 simulator added this to Menu Bar -> Features -> Toggle Appearance