How a Web server actually works ~ with C source code

Posted on in Categories Beyond nixCraft, C Programming, Howto, News, UNIX last updated September 25, 2006

Do you wonder how to write a program that accepts incoming messages with a network socket? Have you ever just wanted your own Web server to experiment and learn with?

Have you ever wondered how a Web server actually works? Experiment with nweb — a simple Web server with only 200 lines of C source code. In this article, Nigel Griffiths provides a copy of this Web server and includes the source code as well. You can see exactly what it can and can’t do.

Well, look no further — nweb is what you need. This is a simple Web server that has only 200 lines of C source code. It runs as a regular user and can’t run any server-side scripts or programs, so it can’t open up any special privileges or security holes.

This article covers:

  • What the nweb server program offers
  • Summary of C functions features in the program
  • Pseudo code to aid understanding of the flow of the code
  • Network socket system calls used and other system calls
  • How the client side operates
  • C source code

nweb only transmits the following types of files to the browser :

  • Static Web pages with extensions .html or .htm
  • Graphical images such as .gif, .png, .jgp, or .jpeg
  • Compressed binary files and archives such as .zip, .gz, and .tar
  • If your favorite static file type is not in this list, you can simply add it in the source code and recompile to allow it.

Read more at IBM developerworks

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

28 comment

  1. how to Write a simple web server in C. This web server only has to respond to GET requests. A web server that serves the same content irrespective of the URL in the GET request is worth 80% of the marks. For further 20% of the marks your server must serve contents based on the file names in the URLs in GET requests.please help me with your source code.

Leave a Comment