List all installed patched and include the date stamp of when they were installed.

rpm -qa --queryformat '%{installtime}  \"%{vendor}\" %{name}-%{version}-%{release}  %{installtime:date}\n' | sort -n

List the installation history of PACKAGENAME.

rpm -qa --queryformat '%{NAME} || %{INSTALLTIME:date}\n' | grep PACKAGENAME

rpm -qlp file.rpm

rpm -Uvh --oldpackage oldversion.rpm

yum downgrade oldversion.rpm

rpm -qa --queryformat '%{installtime}  \"%{vendor}\" %{name}-%{version}-%{release}  %{installtime:date}\n' | sort -n

rpm -e packagename --noscripts

wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm
rpm -Uvh rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm

wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el6.rf.x86_64.rpm
rpm -Uvh rpmforge-release-0.5.3-1.el6.rf.x86_64.rpm

wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
rpm -Uvh epel-release-6-8.noarch.rpm

wget http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-5.noarch.rpm
rpm -Uvh epel-release-7-5.noarch.rpm