Description of problem: I'd like to be able to verify, from a directory of rpm packages, only those packages which are installed on the system, and ignore all others. I know I can do this with a little scripting, but it's quite slow and cumbersome.
You want to verify installed headers and files from the original packages? Try cd /directory/of/rpms rpm -Vp *.rpm 2>&1 | grep -v missing is neither slow nor cumbersome. Not exactly what you asked for, as files that have been erased in installed packages will be undetected, but pretty darn close.