sudo vim /etc/apt/sources.list #或者 sudo gedit /etc/apt/sources.list
删除该文件里的全部内容，复制源直接替换掉，这里提供了阿里云及其他的源，任选一个就可以
# 阿里源 deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
#清华源 deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
#中科大源 deb https://mirrors.ustc.edu.cn/ubuntu/ focal main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal main restricted universe multiverse deb https://mirrors.ustc.edu.cn/ubuntu/ focal-updates main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-updates main restricted universe multiverse deb https://mirrors.ustc.edu.cn/ubuntu/ focal-backports main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-backports main restricted universe multiverse deb https://mirrors.ustc.edu.cn/ubuntu/ focal-security main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-security main restricted universe multiverse deb https://mirrors.ustc.edu.cn/ubuntu/ focal-proposed main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-proposed main restricted universe multiverse
#更新软件列表 sudo apt-get update
#更新软件 sudo apt-get upgrade
大概就可以愉快地玩耍了
linux常用命令
ls ls -l clear cd mkdir rmdir# 删除空目录 rm cp mv chmod [-R] xyz 文件或目录 chmod u=rwx,g=rx,o=r test1 # 修改 test1 权限 chmod (who)(+-=)(rwx) file cat# 由第一行开始显示文件内容 tac# cat倒着写 nl# cat+行号 useradd 选项 用户名 useradd –d /home/sam -m sam userdel 选项 用户名 userdel -r sam df -h mount /dev/hdc6 /mnt/hdc6 umount /dev/hdc6 sudo apt update sudo apt upgrade sudo apt install <package_name> sudo apt install <package_name> --no-upgrade sudo apt install <package_name> --only-upgrade sudo apt install <package_name>=<version_number> apt search libimobile apt show pinta apt list --upgradeable sudo apt autoremove # 清理不再使用的依赖和库文件 ip addr nohup /root/runoob.sh > file.log 2>&1 & kill -9 进程号PID killall -9 name man ps zip tar unzip passwd export shutdown