Before starting to tackle YUM, we will deviate a little by turning our attention towards the process of gathering the necessary software information in order to discover more about the system in general.

To do this, we will begin by running the following command:

# cat /etc/redhat-release; lscpu | grep -i arch; yum repolist all; ls -alsh /etc/yum.repos.d;

At this stage, I will not explain every command shown in the above example, but you will notice that the output is verbose, and it does a good job of detailing the CentOS release information. The information displayed includes details regarding the overall architecture of the server; the domain, time, and date information, and finally, the extent, status, and permissions of the repository list used by Yum.

So far so good, but what if I need to know about the RPM-based packages that are installed on the server? Rather than wading through an entire series of configuration files (or even making an educated guess...