Debian初始化脚本所需的显示服务（X服务器）[重复]

我在 Debian 9.11 上使用 MATE 桌面（pinebook pro）

我有一个初始化脚本，它使用和/etc/init.d/customMapping重新映射我的一些键。这里是setxkbmapxmodmap

#! /bin/sh

### BEGIN INIT INFO
# Provides:          customMapping
# Required-Start:    $local_fs x11-common xserver display
# Required-Stop:     $local_fs x11-common xserver display
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Custom keyboard mapping
# Description:       This is a simple Init script
#                    Custom keyboard mapping
### END INIT INFO
#

# Some things that run always
echo "customMapping script"

# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting script customMapping "
    echo "start" >> /opt/test.txt

    # Make Caps Lock a Control key
    setxkbmap -option ctrl:nocaps > /opt/logs 2>&1

    # Swap Left Control with Left Alt
    setxkbmap -option ctrl:swap_lalt_lctl > /opt/logs 2>&1

    # Make Pause/Break an End key
    xmodmap -e "keycode 127 = End" > /opt/logs 2>&1

    # Make Screen Lock a Home key
    xmodmap -e "keycode 78 = Home" > /opt/logs 2>&1

    ;;
  stop)
    echo "Stopping custom Mapping"
    ;;
  *)
    echo "Usage: /etc/init.d/customMapping {start|stop}"
    exit 1
    ;;
esac

exit 0

如您所见，我在该Required-Start部分中尝试了几种关键字，但这不起作用，当我签入/opt/logs文件时，我看到以下错误消息

无法打开显示“默认显示”

无法打开显示“默认显示”

xmodmap：无法打开显示 ''

xmodmap：无法打开显示 ''

我应该设置什么值Required-Start才能让我的脚本访问display（X 服务器）？值也Default-Start正确吗？

谢谢