rpmrebuild's use

basic use

no need of rpm building knowledge

just rebuild an rpm package from an installed package

you do not find the rpm file ?
just type rpmrebuild package_name

advanced use

you need to have basic knowledge on rpm spec file syntax ( read the RPM-HOWTO, or go to rpm.org)

changes in a file

you have changed a configuration file to match your needs, and want to distribute your changes ?
yo will use the same command : rpmrebuild package_name, because rpmrebuild build the package from the installed files.

add a file

want to add a file to a package ?
Put the file on the wanted directory.
you will use rpmrebuild -e package_name. rpmrebuild will open the specfile in your favorite editor and allow you to add the wanted file in the "%files" section.

advices

rpmrebuild do not need explicitly to be run on root superuser, but you have to be root if some files are root-protected (unix perms 0600)
the specfile is deleted after use. If you want to keep it, use -s option
the rpm files are build on "natural" location (for example, on Redhat/Centos/fedora, on /usr/src/redhat/RPMS, by default).
but you may change this with -d option or with ~/.rpmmacros file (add "%_topdir your_dir")
rpmrebuild has numerous options, check them with man rpmrebuild or rpmrebuild --help