Appendix A. Sample Implementation

This appendix contains a complete C implementation of UUID generation algorithms, including:

Version 1 (time-based) UUID generation
Version 3 (MD5 name-based) UUID generation
Version 4 (random) UUID generation - Version 5 (SHA-1 name-based) UUID generation
Supporting functions for formatting and parsing UUIDs

Note: Due to the length of the implementation code (several hundred lines), please refer to the official RFC 4122 specification at https://www.rfc-editor.org/rfc/rfc4122.txt for the complete source code (pages 17-28).

The sample implementation includes:

Data structures for UUID representation
System-specific clock and random number functions
Complete UUID generation algorithms for all versions
Format conversion functions
Helper utilities