写在前面：笔者由于还在学校学习，学校没有开发给Linux用的上网客户端，所以只能用在windows系统中通过安装虚拟机运行linux比较方便，但没有外网，只有学校的教育网，所以我需要将ubuntu的默认源修改为教育网中的资源才可以完美运行ubuntu，当然这个教程也适用于修改为非教育源。
- 第一步，备份官方的默认源
避免自己手贱操作失误，重装系统太费时间
cp /etc/apt/sources.list /etc/apt/sources.list.bak 此命令是备份该官方源文件
Ubuntu 14.04.4官方默认更新源sources.list
# deb cdrom:[Ubuntu 14.04.4 LTS _Trusty Tahr_ - Release amd64 (20160217.1)]/ trusty main restricted # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://cn.archive.ubuntu.com/ubuntu/ trusty main restricted deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty main restricted ## Major bug fix updates produced after the final release of the ## distribution. deb http://cn.archive.ubuntu.com/ubuntu/ trusty-updates main restricted deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty-updates main restricted ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://cn.archive.ubuntu.com/ubuntu/ trusty universe deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty universe deb http://cn.archive.ubuntu.com/ubuntu/ trusty-updates universe deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty-updates universe ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://cn.archive.ubuntu.com/ubuntu/ trusty multiverse deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty multiverse deb http://cn.archive.ubuntu.com/ubuntu/ trusty-updates multiverse deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty-updates multiverse ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. deb http://cn.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse deb http://security.ubuntu.com/ubuntu trusty-security main restricted deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted deb http://security.ubuntu.com/ubuntu trusty-security universe deb-src http://security.ubuntu.com/ubuntu trusty-security universe deb http://security.ubuntu.com/ubuntu trusty-security multiverse deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu trusty partner # deb-src http://archive.canonical.com/ubuntu trusty partner ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. deb http://extras.ubuntu.com/ubuntu trusty main deb-src http://extras.ubuntu.com/ubuntu trusty main
Ubuntu 16.04官方默认更新源sources.list
#deb cdrom:[Ubuntu 16.04.1 LTS _Xenial Xerus_ - Release amd64 (20160719)]/ xenial main restricted # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://cn.archive.ubuntu.com/ubuntu/ xenial main restricted # deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial main restricted ## Major bug fix updates produced after the final release of the ## distribution. deb http://cn.archive.ubuntu.com/ubuntu/ xenial-updates main restricted # deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial-updates main restricted ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## universe WILL NOT receive any review or updates from the Ubuntu security ## team. deb http://cn.archive.ubuntu.com/ubuntu/ xenial universe # deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial universe deb http://cn.archive.ubuntu.com/ubuntu/ xenial-updates universe # deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial-updates universe
- 第二步，修改官方源为第三方源
sudo vim /etc/apt/sources.list 申请root权限修改该文件（sudo）
附赠网上多数人推荐的第三方源：
清华源ubuntu清华源
- 中科大源：
deb http://mirrors.ustc.edu.cn/ubuntu/ precise-updates main restricted deb-src http://mirrors.ustc.edu.cn/ubuntu/ precise-updates main restricted deb http://mirrors.ustc.edu.cn/ubuntu/ precise universe deb-src http://mirrors.ustc.edu.cn/ubuntu/ precise universe deb http://mirrors.ustc.edu.cn/ubuntu/ precise-updates universe deb-src http://mirrors.ustc.edu.cn/ubuntu/ precise-updates universe deb http://mirrors.ustc.edu.cn/ubuntu/ precise multiverse deb-src http://mirrors.ustc.edu.cn/ubuntu/ precise multiverse deb http://mirrors.ustc.edu.cn/ubuntu/ precise-updates multiverse deb-src http://mirrors.ustc.edu.cn/ubuntu/ precise-updates multiverse deb http://mirrors.ustc.edu.cn/ubuntu/ precise-backports main restricted universe multiverse deb-src http://mirrors.ustc.edu.cn/ubuntu/ precise-backports main restricted universe multiverse deb http://security.ubuntu.com/ubuntu precise-security main restricted deb-src http://security.ubuntu.com/ubuntu precise-security main restricted deb http://security.ubuntu.com/ubuntu precise-security universe deb-src http://security.ubuntu.com/ubuntu precise-security universe deb http://security.ubuntu.com/ubuntu precise-security multiverse deb-src http://security.ubuntu.com/ubuntu precise-security multiverse
- 搜狐源
deb http://mirrors.sohu.com/ubuntu/ precise-updates main restricted deb-src http://mirrors.sohu.com/ubuntu/ precise-updates main restricted deb http://mirrors.sohu.com/ubuntu/ precise universe deb-src http://mirrors.sohu.com/ubuntu/ precise universe deb http://mirrors.sohu.com/ubuntu/ precise-updates universe deb-src http://mirrors.sohu.com/ubuntu/ precise-updates universe deb http://mirrors.sohu.com/ubuntu/ precise multiverse deb-src http://mirrors.sohu.com/ubuntu/ precise multiverse deb http://mirrors.sohu.com/ubuntu/ precise-updates multiverse deb-src http://mirrors.sohu.com/ubuntu/ precise-updates multiverse deb http://mirrors.sohu.com/ubuntu/ precise-backports main restricted universe multiverse deb-src http://mirrors.sohu.com/ubuntu/ precise-backports main restricted universe multiverse
- 网易源
deb http://mirrors.163.com/ubuntu/ precise-updates main restricted deb-src http://mirrors.163.com/ubuntu/ precise-updates main restricted deb http://mirrors.163.com/ubuntu/ precise universe deb-src http://mirrors.163.com/ubuntu/ precise universe deb http://mirrors.163.com/ubuntu/ precise-updates universe deb-src http://mirrors.163.com/ubuntu/ precise-updates universe deb http://mirrors.163.com/ubuntu/ precise multiverse deb-src http://mirrors.163.com/ubuntu/ precise multiverse deb http://mirrors.163.com/ubuntu/ precise-updates multiverse deb-src http://mirrors.163.com/ubuntu/ precise-updates multiverse deb http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiverse
- 阿里源
# deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted deb-src http://archive.ubuntu.com/ubuntu xenial main restricted #Added by software-properties deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted deb-src http://mirrors.aliyun.com/ubuntu/ xenial main restricted multiverse universe #Added by software-properties deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted multiverse universe #Added by software-properties deb http://mirrors.aliyun.com/ubuntu/ xenial universe deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe deb http://mirrors.aliyun.com/ubuntu/ xenial multiverse deb http://mirrors.aliyun.com/ubuntu/ xenial-updates multiverse deb http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse #Added by software-properties deb http://archive.canonical.com/ubuntu xenial partner deb-src http://archive.canonical.com/ubuntu xenial partner deb http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted multiverse universe #Added by software-properties deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe deb http://mirrors.aliyun.com/ubuntu/ xenial-security multiverse
大家，有时候，需要把http改成https，然后，大家可以像我这样，来做好备份，有时候，会因为网络问题，需要用到不同的源，好切换！
/etc/apt/sources.list （比如，这是官方的源）
/etc/apt/sources.list.qinghua （比如，这是清华的源）
/etc/apt/sources.list.zhongkeda （比如，这是中科大的源）
/etc/apt/sources.list.sohu （比如，这是搜狐的源）
/etc/apt/sources.list.wangyi （比如，这是网易的源）
然后，需要用到哪个了，在比如，我需要用到清华源，则，
mv sources.list.qinghua sources.list
然后，把官方的源，暂时改为
mv sources.list sources.list.bak
扩展学习
现在没有可用的软件包 *** ，但是它被其它的软件包引用了 和 E: 无法定位软件包 ***问题解决（思路清晰干货）