Building operating system deliverables, such as RPMs, with a spec file is very useful knowledge. However, sometimes you don't need the rigor of a real spec file. The spec file is, after all, optimized for the scenario where you are not yourself the originator of the code base.
There is a Ruby-based tool called FPM, which can generate source RPMs suitable for building, directly from the command line.
The tool is available on GitHub at https://github.com/jordansissel/fpm.
On Fedora, you can install FPM like this:
yum install rubygems yum install ruby yum install ruby-devel gcc gem install fpm
This will install a shell script that wraps the FPM Ruby program.
One of the interesting aspects of FPM is that it can generate different types of packages; among the types supported are RPM and Debian.
Here is a simple example to make a Hello World shell script:
#...
