ubuntu添加软件源

ubuntu的方便在于很多软件与工具都已经被收录在官方的源里面，但有时候还是需要添加一些源来安装特定的东东，方法如下：
打开终端，先做个备份

sudo cp /etc/apt/sources.list /etc/apt/sources.list_bak

然后 sudo gedit /etc/apt/sources.list

在打开的编辑器最后，加入需要的源地址

PS：注释掉其他行(行首加上#)，也可不操作

最后，更新列表 sudo apt-get update
xd的源设置：

再在/etc/apt/sources.list 开头加入：

#----------------------- xidian -------------------------

deb http://ftp.xdlinux.info/ubuntu/ precise main multiverse restricted universe

deb http://ftp.xdlinux.info/ubuntu/ precise-backports main multiverse restricted universe

deb http://ftp.xdlinux.info/ubuntu/ precise-proposed main multiverse restricted universe

deb http://ftp.xdlinux.info/ubuntu/ precise-security main multiverse restricted universe

deb http://ftp.xdlinux.info/ubuntu/ precise-updates main multiverse restricted universe

deb-src http://ftp.xdlinux.info/ubuntu/ precise main multiverse restricted universe

deb-src http://ftp.xdlinux.info/ubuntu/ precise-backports main multiverse restricted universe

deb-src http://ftp.xdlinux.info/ubuntu/ precise-proposed main multiverse restricted universe

deb-src http://ftp.xdlinux.info/ubuntu/ precise-security main multiverse restricted universe

deb-src http://ftp.xdlinux.info/ubuntu/ precise-updates main multiverse restricted universe

#----------------------- 163 -------------------------

deb http://mirrors.163.com/ubuntu/ percise main restricted universe multiverse

deb http://mirrors.163.com/ubuntu/ percise-security main restricted universe multiverse

deb http://mirrors.163.com/ubuntu/ percise-updates main restricted universe multiverse

deb http://mirrors.163.com/ubuntu/ percise-proposed main restricted universe multiverse

deb http://mirrors.163.com/ubuntu/ percise-backports main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ percise main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ percise-security main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ percise-updates main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ percise-proposed main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ percise-backports main restricted universe multiverse

注意：precise是12.04的代号，更具版本不同做相应修改：

trusty(14.04) quantal (12.10) precise (12.04) oneiric (11.10) natty (11.04) maverick (10.10) lucid (10.04)

使用 sudo apt-get update 同步本地包数据库。

使用 sudo apt-get upgrade 升级所有已安装的软件包。