Build a simple HTTP server in C

Nathan H picture Nathan H · Oct 7, 2008 · Viewed 185k times · Source

I need to build a simple HTTP server in C. Any guidance? Links? Samples?

Answer

Ates Goral picture Ates Goral · Oct 7, 2008

I'd recommend that you take a look at: A Practical Guide to Writing Clients and Servers

What you have to implement in incremental steps is:

  1. Get your basic TCP sockets layer running (listen on port/ports, accept client connections and send/receive data).
  2. Implement a buffered reader so that you can read requests one line (delimited by CRLF) at a time.
  3. Read the very first line. Parse out the method, the request version and the path.
  4. Implement header parsing for the "Header: value" syntax. Don't forget unfolding folded headers.
  5. Check the request method, content type and content size to determine how/if the body will be read.
  6. Implement decoding of content based on content type.
  7. If you're going to support HTTP 1.1, implement things like "100 Continue", keep-alive, chunked transfer.
  8. Add robustness/security measures like detecting incomplete requests, limiting max number of clients etc.
  9. Shrink wrap your code and open-source it :)