rpm update: what happens to modified files

Question

What happens at rpm -U.. if any file of the package being updated has been modified? Is it left updated with a new one, or the new (modified) file is kept with new extension?

Answer 1

RPM will overwrite any files that have changed unless they are explicitly designated as "configuration" files using the %config flag. Then it will make a copy of either the new one ( *.rpmnew ) or the old one ( *.rpmsave ) based on whether or not the config file is flagged as noreplace . See this reference for more details.