While every directive we've seen so far is used in the %files list, the %package directive is different. It is used to permit the creation of more than one package per spec file and can appear at any point in the spec file. These additional packages are known as subpackages. Subpackages are named according to the contents of the line containing the %package directive. The format of the package directive is:
The <string> should be a name that describes the subpackage. This string is appended to the base package name to produce the subpackage's name. For example, if a spec file contains a name tag value of "foonly", and a "%package doc" line, then the subpackage name will be foonly-doc.
As we mentioned above, the name of a subpackage normally includes the main package name. When the -n option is added to the %package directive, it directs RPM to use the name specified on the %package line as the entire package name. In the example above, the following %package line would create a subpackage named foonly-doc:
The following %package line would create a subpackage named doc:
%package -n doc
The %package directive plays another role in subpackage building. That role is to act as a place to collect tags that are specific to a given subpackage. Any tag placed after a %package directive will only apply to that subpackage.
Finally, the name string specified by the %package directive is also used to denote which parts of the spec file are a part of that subpackage. This is done by including the string (along with the -n option, if present on the %package line) on the starting line of the section that is to be subpackage-specific. Here's an example:
… %package -n bar … %post -n bar …
In this heavily edited spec file segment, a subpackage called bar has been defined. Later in the file is a post-install script. Because it has subpackage bar's name on the %post line, the post-install script will be part of the bar subpackage only.
For more information on building subpackages, please see Chapter 18.