使用xshell连接RHEL5.8服务器，敲入xclock命令想验证图形化安装条件，但是显示无此命令。
[root@template ~]# xclock
-bash: xclock: command not found原来这台服务器没有安装xclock，使用yum安装记录如下：
[root@localhost ~]# yum install xorg-x11-apps Loaded plugins: katello, product-id, security, subscription-manager Updating certificate-based repositories. Unable to read consumer identity Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package xorg-x11-apps.x86_64 0:7.1-4.0.1.el5 set to be updated --> Finished Dependency Resolution Dependencies Resolved =============================================================================================================================================================================================== Package Arch Version Repository Size =============================================================================================================================================================================================== Installing: xorg-x11-apps x86_64 7.1-4.0.1.el5 base 265 k Transaction Summary =============================================================================================================================================================================================== Install 1 Package(s) Upgrade 0 Package(s) Total download size: 265 k Is this ok [y/N]: y Downloading Packages: xorg-x11-apps-7.1-4.0.1.el5.x86_64.rpm | 265 kB 00:00 Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Installing : xorg-x11-apps 1/1 Installed products updated. Installed: xorg-x11-apps.x86_64 0:7.1-4.0.1.el5 Complete!