Michael Stenner wrote: > On Wed, Sep 22, 2004 at 06:16:14PM -0500, Christopher J. Bottaro wrote: >> where can i get documentation on the header.info format? where can i get >> more detailed information on the inner workings of yum beyond what is >> covered by http://linux.duke.edu/projects/yum/howitworks.ptml. how does >> it know what is installed on your system vs what is available in the >> repos vs >> what you have but needs to be updated, etc? the stuff stored >> in /var/cache/yum is only the package info for the repositories, right? >> (i.e. the info in the caches tell nothing about your actual system)? yum >> then runs rpm to query your actual system then it compares that output to >> what it has in the caches...? > > * if you are planning on working on yum stuff (whether you ever > intend to contribute it or not), you should do new develpment on > the cvs branch, which is available as 2.1.x. In that, the > header.info and header files are no longer used. They're replaced > by a series of xml files that contains the necessary data. > > * there is no real documentation of the inner workings of yum other > than the source code itself. > > * the information about what's available in the repos is contained in > header.info and header files for the old style, and in the xml > files for the new style. This info is on the repo and is fetched > (what's needed and new, anyway) each time yum runs. > > * yum can tell what's on your system because rpm keeps a database > with all that information in it. > > * yum does not run the rpm executable, but rather uses the rpm-python > bindings which allow direct (and cleaner) access to the > information. This is how the rpmdb is access, how packages are > installed, etc. > > If you have one or two small followup questions, feel free to ask > them. Otherwise, you should simply turn to the source code. I hope > that helps. > -Michael Ahh, thanks for the help. Guess I got to learn Python, huh? ;)
