apt-get无法找到安装包解决方法--添加源

When you try to install a package using apt-get, APT searches it’s own database for the package name, if the package is available in the database, then it looks for the repository from where to download the package. It then download the package
from that repository and installs it.

If the package name does not exist in APT’s database, it does not have any idea what you are trying to install andyou see the following error message:

#  apt-get install <packagename> Reading package lists... Done Building dependency tree... Done Package aptitude is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package <packagename> has no installation candidate

 

So, the above error occurs for 2 reasons:

1) The APT’s database is not updated.

A quick fix is to update the APT’s database as per the defined sources list.

# apt-get update # apt-get upgrade # apt-get install <packagename>

This is it. If isn’t fixed, check point #2 below.

2) The package itself isn’t available on the official Ubuntu repository.

In such a situation, you have to add a 3rd party repository to your /etc/apt/sources.list file and install the package, however, try such repositories at your own risk.

当我们在使用ubuntu命令窗，输入安装命令的时候，有些安装包总是提示

E: Package <packagename> has no installation candidate错误，于是便开始google，寻找原因。但苦苦追寻，能查到的都是
一些叫我们输入指令的语句  如sudo apt-get update等之类的命令，但该命令不管用。这是因为在我们的/etc/apt/sources.list
文件下，拥有的是只是一些系统初装的源，后期的一些源还是得自己添加的，不然网上的很多资源包都是无法使用的。下面我就贴上
我在网站上找到的各种源。

sources.list（源）

位置：/etc/apt/sources.list

常见的源：

1 中国科技大学源

deb http://debian.ustc.edu.cn/ubuntu/ hardy main multiverse restricted universe

deb http://debian.ustc.edu.cn/ubuntu/ hardy-backports main multiverse restricted universe

deb http://debian.ustc.edu.cn/ubuntu/ hardy-proposed main multiverse restricted universe

deb http://debian.ustc.edu.cn/ubuntu/ hardy-security main multiverse restricted universe

deb http://debian.ustc.edu.cn/ubuntu/ hardy-updates main multiverse restricted universe

deb-src http://debian.ustc.edu.cn/ubuntu/ hardy main multiverse restricted universe

deb-src http://debian.ustc.edu.cn/ubuntu/ hardy-backports main multiverse restricted universe

deb-src http://debian.ustc.edu.cn/ubuntu/ hardy-proposed main multiverse restricted universe

deb-src http://debian.ustc.edu.cn/ubuntu/ hardy-security main multiverse restricted universe

deb-src http://debian.ustc.edu.cn/ubuntu/ hardy-updates main multiverse restricted universe

2 北京交大源

deb http://mirror.bjtu.edu.cn/Ubuntu/ hardy main restricted universe multiverse

deb http://mirror.bjtu.edu.cn/Ubuntu/ hardy-backports restricted universe multiverse

deb http://mirror.bjtu.edu.cn/Ubuntu/ hardy-proposed main restricted universe multiverse

deb http://mirror.bjtu.edu.cn/Ubuntu/ hardy-security main restricted universe multiverse

deb http://mirror.bjtu.edu.cn/Ubuntu/ hardy-updates main restricted universe multiverse

deb-src http://mirror.bjtu.edu.cn/Ubuntu/ hardy main restricted universe multiverse

deb-src http://mirror.bjtu.edu.cn/Ubuntu/ hardy-backports main restricted universe multiverse

deb-src http://mirror.bjtu.edu.cn/Ubuntu/ hardy-proposed main restricted universe multiverse

deb-src http://mirror.bjtu.edu.cn/Ubuntu/ hardy-security main restricted universe multiverse

deb-src http://mirror.bjtu.edu.cn/Ubuntu/ hardy-updates main restricted universe multiverse

3 台湾大学源

deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy main restricted universe multiverse

deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy main restricted universe multiverse

deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy-updates main restricted universe multiverse

deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy-updates main restricted universe multiverse

deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy-backports main restricted universe multiverse

deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy-backports main restricted universe multiverse

deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy-security main restricted universe multiverse

deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy-security main restricted universe multiverse

deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy-proposed main multiverse restricted universe

deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ hardy-proposed main restricted universe multiverse

4 CN99源

deb http://Ubuntu.cn99.com/ubuntu/ hardy main restricted universe multiverse

deb http://Ubuntu.cn99.com/ubuntu/ hardy-security main restricted universe multiverse

deb http://Ubuntu.cn99.com/ubuntu/ hardy-updates main restricted universe multiverse

deb http://Ubuntu.cn99.com/ubuntu/ hardy-proposed main restricted universe multiverse

deb http://Ubuntu.cn99.com/ubuntu/ hardy-backports main restricted universe multiverse

deb-src http://Ubuntu.cn99.com/ubuntu/ hardy main restricted universe multiverse

deb-src http://Ubuntu.cn99.com/ubuntu/ hardy-security main restricted universe multiverse

deb-src http://Ubuntu.cn99.com/ubuntu/ hardy-updates main restricted universe multiverse

deb-src http://Ubuntu.cn99.com/ubuntu/ hardy-proposed main restricted universe multiverse

deb-src http://Ubuntu.cn99.com/ubuntu/ hardy-backports main restricted universe multiverse

5 Lupaworld源

deb http://mirror.lupawor a284
ld.com/ubuntu hardy main restricted universe multiverse

deb http://mirror.lupaworld.com/ubuntu hardy-security main restricted universe multiverse

deb http://mirror.lupaworld.com/ubuntu hardy-updates main restricted universe multiverse

deb http://mirror.lupaworld.com/ubuntu hardy-backports main restricted universe multiverse

deb http://mirror.lupaworld.com/ubuntu hardy-proposed main restricted universe multiverse

deb-src http://mirror.lupaworld.com/ubuntu hardy main restricted universe multiverse

deb-src http://mirror.lupaworld.com/ubuntu hardy-security main restricted universe multiverse

deb-src http://mirror.lupaworld.com/ubuntu hardy-updates main restricted universe multiverse

deb-src http://mirror.lupaworld.com/ubuntu hardy-backports main restricted universe multiverse

deb-src http://mirror.lupaworld.com/ubuntu hardy-proposed main restricted universe multiverse

（注释：deb代表的是我们需要的deb软件包，deb-src 是指下载源代码得指示。之后是包的来源地址，再在后面是系统的标记。之后的main代表的是主要软件包，universe是不被官方支持的自由软件。)
                                         如何更改源呢？

1、首先备份Ubuntu 8.04 的当前更新源列表（以备不测）

      sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup （备份下当前的源列表）

2、修改更新源
      sudo gedit /etc/apt/sources.list
3[b]、在里面我选择在后面添加源；[/b]

4、通知Ubuntu 11.10 启用新的更新源

     sudo apt-get update

我的终端命令如图：

root@ubuntu：~# sudo apt-get update