===== Shortest RPM-HowTo =====

==== Preparation ====

Before you think about putting your code into an RPM, it is much useful if you
have at least three targets in your Makefile:

<ldl>
<ldt>clean</ldt><ldd>removed all generated files</ldd>
<ldt>all</ldt><ldd>compile all necessary files</ldd>
<ldt>install</ldt><ldd>copy the files into the system directories</ldd>
</ldl>

It is important that after **make install** the binaries are well installed, and that even after removal of the source-direcotry, the program still runs. Furthermore it is necessary to have an optional variable for the Makefile, preferably called RPM_BUILD_ROOT, that is prefixed on all installed files. So, for example, if RPM_BUILD_ROOT points to /tmp/rpm, a file usually installed in /usr/bin would be installed in /tmp/rpm/usr/bin. Once you have done this, you may take the next step: The spec file

==== Spec-files ====

If you are working with xemacs (I advise you too, but vi seems to be pretty OK, too), you can open a new file in your project-directory that is called <project_name>.spec XEmacs then will fill it with the standard lines. I will go through the lines from Etrans.spec, the specification-file used in the Etrans-project:
</project_name>

<code>
Summary: Etrans - the Software Radio from EPFL/Eurecom
Name: Etrans
Version: 0.3
Release: 1
URL: http://lcmpc10.epfl.ch]
Source0: %{name}-%{version}.tar.gz
License: GPL
Group:Development/System 
BuildRoot: %{_tmppath}/%{name}-root
Requires: rtlkernel = 2.4.4rtl rtlinux = 3.1

%description
This is a remake of the software radio originally written by
Raymond Knopp and others. It is put in a usable shape, bound
with a frontend and should also get some documentation.

%prep
%setup -q

%build
make

%install
rm -rf $RPM_BUILD_ROOT
make install

%clean
rm -rf $RPM_BUILD_ROOT

%files
%defattr(-,root,root)
/opt/radio
/etc/profile.d
/dev/daq0

%changelog
* Tue Mar  5 2002 root <>
- Initial build.
</code>

We will no go through the file line by line and look what this rpm-spec file is all about:

  * **Summary** is a one-liner for a description.
  * **Name** is the base-name of your Project. It has to match with your directory-name and with the name of your .tgz In our example the project Etrans in it's version 0.3 is stored in a directory called Etrans-0.3 and it's source-tarball is called Etrans-.0.3.tgz So the name would be Etrans
  * **Version** In our example, this is 0.3
  * **URL** is an optional URL where the source can be get
  * **License** should be GPL, but of course may differ
  * **Group** is one of the groups described in /usr/share/doc/rpm-4.0.3/GROUPS
  * **Requires** gives a list of packages that need to be installed. It is important to have a space before and after the '=', ifnot the file 'rtlkernel=2.4.4rtl' is expected.
  * **description** is a longer description
  * **build** commands to build the binaries. In some cases you may want to include a ./configure here.
  * **install** the variable RPM_BUILD_ROOT is created in the **prep** step and points to the base directory for the installation. 'make install' then puts the files in this directory, if all is put up well. For some programs you'll need a 'configure --prefix=$RPM_BUILD_ROOT' in the **build** stage. But Etrans looks directly for the environment-variable RPM_BUILD_ROOT and puts the files under this directory
  * **clean** after the binaries are taken from the install-directory, this is called to clean up the installation-directory. The command presented here is a bit of a security-hazard, as RPM_BUILD_ROOT may point to '/' and thus the whole filesystem would be deleted.
  * **files** indicates which files need to be taken into the rpm-package. All names and directories are relative to $RPM_BUILD_ROOT. If a name points to a directory, it is stepped through recursively and all files are included in the rpm.
  * **changelog** don't forget to update your changes

==== Building of RPM ====

Once you have your spec-file, you only need to pack up your project and let it build:

<code>
tar cvzf Etrans-0.3.tar.gz Etrans-0.3/.
rpmbuild -ta Etrans-0.3.tar.gz
</code>

The '.' in Etrans-0.3/. is there because on my system, Etrans-0.3 is a symbolic link. So rather than tarring a symbolic link, I'd like to tar the content of this symbolic link! The second command then does everything from decompressing the tar.gz to calling all necessary scripts and building up a rpm. If all goes right, you can find your rpm in

<code>
/usr/src/redhat/RPMS/i386
</code>

If you're on an intel machine, of course. Try the file on a clean, freshly installed machine, to look
if you didn't forget any dependencies.

==== Links ====

  * [[http://www.linuxdoc.org/HOWTO/RPM-HOWTO/index.html|RPM @ LinuxDoc]]
  * [[http://www.rpm.org/max-rpm The official|RPM-guide]]
  * [[http://freshrpms.net/docs/fight.html|Fighting RPMs]]