Deep Dive into Unix Domain Sockets: Theory, Code, and Real‑World Use
Introduction Inter‑process communication (IPC) is the backbone of any modern operating system. While pipes, shared memory, and message queues each have their niche, Unix domain sockets (often called Unix sockets or IPC sockets) occupy a sweet spot: they provide a network‑style API with the speed and security of local communication. In this article we will explore Unix domain sockets from first principles to advanced usage, covering: The conceptual model and history of Unix sockets The three socket types (stream, datagram, seqpacket) and address families Practical examples in C and Python, including non‑blocking I/O and event loops Security, performance, and debugging considerations Real‑world scenarios where Unix sockets shine (web servers, databases, systemd, containers) Advanced techniques such as passing file descriptors and using ancillary data By the end of this guide you should be able to design, implement, and troubleshoot Unix socket based IPC solutions confidently. ...