I use "yum list installed" to determine if a package has been installed on centos. In particular, I was interested in the "man" program, installed with the command "yum install man".
In Centos6, if I look at the results, I see that "man" was installed. This is good.
In Centos7, if I look at the results, I see that "man-db" was installed. This is inconsistent.
The result is that the generic algorithm:
if I want package X , check the "yum list installed" output.
If X is not listed, install it, otherwise assume it's already installed.
Is there a reason for this inconsistency? The above algorithm works with most other packages.