talkback

enableTalkbackAll() {
    for device in $(adb devices | grep 'device$' | cut -f1)
    do
        adb -s "$device" shell settings put secure enabled_accessibility_services 'com.google.android.marvin.talkback/com.google.android.marvin.talkback.TalkBackService'
        adb -s "$device" shell settings put secure accessibility_enabled 1
    done
    echo "Talkback enabled on all devices."
}

disableTalkbackAll() {
    for device in $(adb devices | grep 'device$' | cut -f1)
    do
        adb -s "$device" shell settings put secure enabled_accessibility_services 'null'
        adb -s "$device" shell settings put secure accessibility_enabled 0
    done
    echo "Talkback disabled on all devices."
}