4n3i5v74 / python-cgi-example

A simple server and hit counter entirely in Python designed to demonstrate how to write CGI scripts.

Simple python3 cgi script.

Quickstart

Clone the repo:

git clone https://github.com/nbeaver/python-cgi-example

Move into the directory:

cd python-cgi-example

Run this command:

python3 ./http_server.py

This should open a browser page showing the current date and a hit counter that increases each time the page is reloaded.

Modify cgi-bin/hit_counter.py and reload the page to see the effects.

Hit Ctrl-C to stop the web browser once you are finished.

Motivation

Most tutorials for Python CGI scripts I have seen have flaws such as:

• Requiring installation of a web server like apache instead of just serving from a local directory using Python's SimpleHTTPServer.
• Requiring write access to directories like /var/www/cgi-bin/.
• Not opening the browser to the correct page when the server starts.
• Not storing the cgi script in a separate directory from the server source code.
• Not providing the code in a convenient bundle to download, run, and modify.

as well as pedagogical flaws such as:

• Not distinguishing the HTTP header from the HTML.
• Sending plain text instead of HTML.
• Sending static HTML instead of dynamic output.
• Sending dynamic output that could be done entirely client-side.

The included CGI script is a simple hit counter that writes to a file on disk to store the count.

Note

This is a pedagogical exercise, and is not the best way to implement a hit counter in general.