How to save the brightness settings (backlight brightness) of a notebook in linux)

In linux, how does one save the screen brightness settings (backlight brightness) of a notebook? My linux desktop version is linux mint13 maya, and the screen brightness is the brightest each time it is started, you can adjust the brightness of the backlight through Fn + F6/F7, but the maximum brightness will be restored after restart.
Do you need to adjust the brightness by Fn + F6/F7 after each boot? Is there a permanent solution? Of course! 1, cat/etc/default/acpi-support, found that there is such a comment: # Note: to enable "laptop mode" (to spin down your hard drive for longer # periods of time ), install the laptop-mode-tools package and configure # it in/etc/laptop-mode/laptop-mode.conf. well, we had to install the laptop-mode-tools tool first. OK. It's very simple. After apt-get install laptop-mode-tools is installed, it will automatically enable the laptop mode, open/etc/laptop-mode/laptop-mode.conf below to configure www.2cto.com 2, configure/etc/laptop-mode/laptop-mode.conf
(1) use laptop mode in alternating current mode: # Enable laptop mode when on AC power. # ENABLE_LAPTOP_MODE_ON_AC = 1
# The default value of the battery is 1 (2), and the LCD brightness control is configured.
In/etc/laptop-mode/laptop-mode.conf left find right all wood have found CONTROL_BRIGHTNESS this option, view help manual: man laptop-mode.conf, the LCD brightness was originally controlled in/etc/laptop-mode/conf. d/lcd-brightness.conf in this file. OK. Open this file and perform the following settings: # shocould laptop mode tools control LCD brightness? # Set to 1 and enable CONTROL_BRIGHTNESS = 1 # Commands to execute to set the brightness on your LCD # "echo 13" means to write brightness Value 13 to the BRIGHTNESS_OUTPUT file, the brightness value can be set based on your own conditions. Www.2cto.com BATT_BRIGHTNESS_COMMAND = "echo 13" Highlight = "echo 13" Highlight = "echo 13" BRIGHTNESS_OUTPUT = "/sys/class/backlight/acpi_video0/brightness" OK, restart. In this way, you do not need to manually press Fn + F6/F7 each time you start the system. Note: Writing echo xx>/sys/class/backlight/acpi_video0/brightness to rc. local does not work. Using laptop mode tools for control can achieve our goal. From archlinuxchina Forum