C powers the networking stack, web servers, and security tools. Today you build a TCP server with POSIX sockets, understand buffer overflow vulnerabilities, and apply secure coding practices that prevent the most common C security bugs.
By the end of this lesson you will write a TCP server that accepts connections and echoes data, explain how a stack-based buffer overflow leads to arbitrary code execution, apply bounds-checking to prevent buffer overflows, use Address Sanitizer to detect memory errors, and list the top five C secure coding rules.
sockets is the foundation of Day 5. Every concept that follows builds on the mental model you establish here. The most effective approach is to understand the principle first, then apply it — skipping straight to implementation creates gaps that compound into confusion later.
Work through each example in this lesson sequentially. The concepts connect, and the order is deliberate. If something is unclear, slow down at that point rather than pushing past it — a ten-minute pause now saves hours of debugging later.
Understanding sockets requires seeing it in motion. The code below is not a complete application — it is a minimal, working illustration of the key mechanism. Study the pattern, run it, break it deliberately, then fix it. That cycle builds real comprehension.
Once the basic pattern works, the logical next step is TCP server in C. This is where the abstraction becomes useful — you move from understanding the mechanism to applying it to real problems. The transition is usually smaller than it feels. Most of the hard work happened in Section 1.
secure coding completes today's picture. It is where sockets and TCP server in C converge into a pattern you can apply to novel problems. This integration step is often where the day's learning consolidates — if the earlier sections felt abstract, this one typically makes them click.
Implementing sockets alone handles the happy path. Real systems encounter edge cases, invalid input, and unexpected state. Missing TCP server in C means missing those guards.
Combining sockets with TCP server in C gives you a complete, defensible implementation. The extra lines cost ten minutes; the robustness they add is worth hours of debugging time.
Several mistakes appear consistently when engineers encounter C in the Real World: Networking & Security for the first time. Recognizing them now costs nothing; encountering them in production costs hours.
Two intensive days (Thu–Fri) with an instructor who has taught thousands of engineers. Cohorts in 5 cities, June–June–October 2026 (Thu–Fri).
Reserve Your Seat — $1,490Before moving on, you should be able to answer these without looking: