1.显示器名字
xrandr -q | grep " connected"
HDMI-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 527mm x 297mm
DP-4 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 527mm x 297mm
2.调节亮度
xrandr --output HDMI-0 --brightness 0.5
xrandr --output DP-4 --brightness 0.5