I have changed several configuration files in programs installed with yum, and since I've long forgotten exactly what changes I made I'd like to compare the current modified state of these files with the original state of the files as they were when I originally installed them.

I am wondering if there is a way to, rather than reinstall a whole program, just use yum to specify a file I'd like to retrieve in its original form from the yum repository?

(e.g. maybe something like... 'yum restore mysqld /etc/my.cnf /tmp', which for example would retrieve the original /etc/my.cnf from the mysqld package and put it in /tmp for me to examine)

I'd really like to be able to examine the original state of several configuration files in a clean and simple way rather than having to backup my changed configuration files, uninstall the packages, reinstall them to get the original files, then when I'm done with my comparisons restore my changed config files on top of the original ones to get back to where I was.

You can use this to verify all the files in the package. The first 9 characters on each line are documented in the man rpm page under Verify Options. If any file's content is changed, it's MD5 sum will have changed, so the third column will be 5. The rpm command (and therefore yum) is very good about not overwriting configuration files you've modified. Instead, the new files are installed as file.rpmnew.

In fact, right now, issue this command. If you've updated almost anything, you're likely to have a few new config files.

I ran 'rpm -Vv mysql' and didn't see any files that have changed. I'm surprised because I'd expect /etc/my.cnf to show up, because I changed it. I also am not seeing any files when I do 'ls /etc/*.rpmnew'. I even did a 'locate *rpmnew' and nothing appeared.

Is there any way using either yum (preferrably) otherwise rpm to easily get at an original configuration file?

The mysql package doesn't have any files in /etc/, but mysql-server does.

A while back I put some effort into finding a way to do this. I found the repoquery command (in the yum-utils package) that lists the contents of a package (even if not installed), but I have yet to find a command that will actually allow me to see one individual file in a package.

Of course, you can always download the rpm file itself from the repo (with wget, curl or a browser) and then use something like this to extract and compare a file. I don't know if I have the syntax right. I didn't run this command and I'm not very familiar with cpio.