在终端里调整笔记本屏幕亮度（/sys 背光接口）

读写 /sys/class/backlight/.../brightness 调节屏幕亮度，或使用更友好的 brightnessctl 按百分比调整。

Linux背光显示器笔记本屏幕亮度中风险

用 `echo 700 | sudo tee /sys/class/backlight/intel_backlight/brightness` 写入亮度值，或直接运行 `brightnessctl set 80%`。

01命令

命令

$ echo 700 | sudo tee /sys/class/backlight/intel_backlight/brightness

02作用说明

先用 `cat /sys/class/backlight/*/max_brightness` 查看最大值，再写入 0 到最大值之间的数字。目录名取决于显卡驱动，常见有 intel_backlight、amdgpu_bl0、acpi_video0。日常使用推荐 brightnessctl：`brightnessctl set +10%` 调亮一档，`brightnessctl set 50%` 设为指定百分比，无需每次找目录。

03风险

风险中风险

使用条件Works on most laptops with an ACPI backlight; the folder under /sys/class/backlight/ may be named acpi_video0 or amdgpu_bl0 instead of intel_backlight. brightnessctl (packaged in most distros) does the same without sudo: brightnessctl set 80%

!注意: 不要把值写进 max_brightness 文件，也不要用 `sudo echo N > 文件` 的写法——重定向是以普通用户身份执行的，会报权限错误，应改用 `sudo tee`。

04撤销

撤销

$ echo 900 | sudo tee /sys/class/backlight/intel_backlight/brightness

05来源

brightnessctl(1) - Linux manual page
Ubuntu Manpages · technical · 2026-09-17
依据: brightnessctl reads and writes the brightness of backlight devices; commands like 'brightnessctl set 80%' adjust the current brightness as a percentage without root when the user is in the video group.
Backlight - ArchWiki
Arch Linux Wiki · technical · 2026-09-17
依据: Documents that backlight brightness is controlled by writing to /sys/class/backlight/<device>/brightness and lists device names such as intel_backlight and acpi_video0.

最后验证: 2026-09-18 · 分类: 系统与设置