修改配置文件/etc/apt/sources.list
內容替換為
阿里鏡像源
deb http://mirrors.aliyun.com/ubuntu/ vivid main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ vivid-security main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ vivid-updates main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ vivid-proposed main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ vivid-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ vivid main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ vivid-security main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ vivid-updates main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ vivid-proposed main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ vivid-backports main restricted universe multiverse12345678910
執行，正常則表示成功
apt-get update
安裝tree,用於查看目錄
apt-get install tree