sb_release -c //查看系统代号
#更新源/etc/apt/sources.list //打开更新目录
deb https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic main restricted universe multiverse
deb-src https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic main restricted universe multiverse
deb https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic-security main restricted universe multiverse
deb-src https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic-security main restricted universe multiverse
deb https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic-updates main restricted universe multiverse
deb-src https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic-updates main restricted universe multiverse
deb https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic-backports main restricted universe multiverse
deb-src https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic-backports main restricted universe multiverse
deb https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic-proposed main restricted universe multiverse
deb-src https://linux.xidian.edu.cn/mirrors/ubuntu/ cosmic-proposed main restricted universe multiverse
#更新之后执行数据缓存
sudo apt-get update
sudo apt-get upgrade
ubuntu 18.04 关闭合盖休眠
编辑下列文件：/etc/systemd/logind.conf
- HandlePowerKey按下电源键后的行为，默认power off
- HandleSleepKey 按下挂起键后的行为，默认suspend
- HandleHibernateKey按下休眠键后的行为，默认hibernate
- HandleLidSwitch合上笔记本盖后的行为，默认suspend（改为ignore；即合盖不休眠）在原文件中，还要去掉前面的#
然后将其中的：
- HandleLidSwitch=suspend
- 改成下面，记得去掉“#”号：
- HandleLidSwitch=ignore
注：在Ubuntu18.04和Ubuntu16.04笔记本电脑，下面测试可以使用。
运行：systemctl restart systemd-logind就会生效。