Magisk volume key selection function

magisk-volume-key-selection.sh

volumeselect() {
    while true; 
        do
            getevent -lc 1 2>&1 | grep VOLUME | grep DOWN > "$TMPDIR"/events

            if grep VOLUME "$TMPDIR"/events >/dev/null; 
                then break
            fi
    done
    if grep VOLUMEUP "$TMPDIR"/events >/dev/null; 
        then return 0
        else return 1
    fi
}