Find and replace feature is always handy. It can turn into a torture when it comes to change or delete a simple constant string in a text file. There is a handy tool in linux for doing these kind of tihngs. Actually sed is not a text editor but it is used outside of the text file to make changes.
After registering redhat linux system for rhn, yum update command returned "No Packages marked for Update" # yum updateLoaded plugins: downloadonly, securitySetting up Update ProcessNo Packages marked for Update