http://ask.xmodulo.com/enable-nux-dextop-repository-centos-rhel.html
Question: I would like to install a RPM package which is available only in Nux Dextop repository. How can I set up Nux Dextop repository on CentOS or RHEL?
Nux Dextop is a third-party RPM repository which contains many popular desktop and multimedia related packages (e.g., Ardour, Shutter, etc) for CentOS, RHEL and ScientificLinux. Currently, Nux Dextop repository is available for CentOS/RHEL 6 and 7.
To enable Nux Dextop repository on CentOS or RHEL, follow the instructions below.
First of all, understand that Nux Dextop is designed to coexist with EPEL repository. So you need to enable EPEL in order to use Nux Dextop repo.
After enabling EPEL, go ahead and install Nux Dextop repository as follows.
As the first step, import the official GPG key of Nux Dextop repository:
$ sudo rpm --import http://li.nux.ro/download/nux/RPM-GPG-KEY-nux.ro
Without GPG key import, you will get the following warning while installing Nux Dextop.
warning: /var/tmp/rpm-tmp.y4VqPB: Header V4 RSA/SHA1 Signature, key ID 85c6cd8a: NOKEY
Then go ahead and install Nux Dextop with yum command as follows. Note that Nux Dextop repository comes as an architecture in-dependent RPM, so you can install the same RPM on both 32-bit and 64-bit architectures.
On CentOS/RHEL 6.*:
$ sudo rpm -Uvh http://li.nux.ro/download/nux/dextop/el6/x86_64/nux-dextop-release-0-2.el6.nux.noarch.rpm
On CentOS/RHEL 7:
$ sudo rpm -Uvh http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-1.el7.nux.noarch.rpm
Now verify that Nux Dextop repository is successfully installed:
$ yum repolist
For Repoforge/RPMforge Users
According to the author, Nux Dextop is known to cause conflicts with other third-party RPM repos such as Repoforge and ATrpms. Therefore, if you enabled any third-party repos other than EPEL, it is highly recommend you set Nux Dextop repository to "default off" state. That is, open /etc/yum.repos.d/nux-dextop.repo with a text editor, and change "enabled=1" to "enabled=0" under nux-desktop.
$ sudo vi /etc/yum.repos.d/nux-dextop.repo
Then whenever you want to install a package from Nux Dextop repo, explicitly enable the repo as follows.
$ sudo yum --enablerepo=nux-dextop install <package-name>
问题：我想要在我的CentOS桌面上试试Shutter屏幕截图程序，但是，当我试着用yum来安装Shutter时，它总是告诉我“没有shutter包可用”。我怎样才能在CentOS上安装Shutter啊？
Shutter是 一个用于Linux桌面的开源（GPLv3）屏幕截图工具。它打包有大量用户友好的功能，这让它成为Linux中功能最强大的屏幕截图程序之一。你可以用 Shutter来捕捉一个规则区域、一个窗口、整个桌面屏幕、或者甚至是来自任意专用地址的一个网页的截图。除此之外，你也可以用它内建的图像编辑器来对 捕获的截图进行编辑，应用不同的效果，将图像导出为不同的图像格式（svg，pdf，ps），或者上传图片到公共图像主机或者FTP站点。
Shutter 在 CentOS (截止至版本 7)上没有预先构建好的软件包。幸运的是，有一个第三方提供的叫做 Nux Dextop 的 RPM 中提供了 Shutter 软件包。 所以在 CentOS 上启用 Nux Dextop 软件库，然后使用下列命令来安装它：
- $ sudo yum --enablerepo=nux-dextop install shutter
