To find the package that owns a particular file that is installed on your system, you would do:
rpm -q --whatprovides /full/path/to/file
for example, on CentOS-4 if I do:
rpm -q --whatprovides /bin/bash
I get this as an answer:
bash-3.0-19.2
rpm -qf /path/to/file
will give you the same results
-Jay