In addition to the built-in macros, you can define your own to make it easier to manage your packages. Define a new spec file macro with the following syntax:

%define macro_name value

For example:

%define major 2

%define minor 2

%define patchlevel 7

You can then use a macro with the %macro_name or %{macro_name} syntax. For example:

Version: %{major}.%{minor}.%{patchlevel}

You can also expand the results of running shell commands using a %(command) syntax with parenthesis instead of curly braces. For example:

%define today %(date)