Sunifdef is a commandline tool for eliminating superfluous preprocessor clutter from C and C++ source files. It is a more powerful successor to the FreeBSD 'unifdef' tool. Sunifdef is most useful to developers of constantly evolving products with large code bases, where preprocessor conditionals are used to configure the feature sets, APIs or implementations of different releases. In these environments the code base steadily accumulates #ifdef pollution as transient configuration options become obselete. Sunifdef can largely automate the recurrent task of purging redundant #if logic from the code.