harsh manvar

How to read all HTTP headers in Python CGI script?

harsh manvar

Updated on 24-Mar-2026 2K+ Views

When working with Python CGI scripts, you often need to access HTTP headers sent by the client. Apache's mod_cgi automatically converts HTTP headers into environment variables with an HTTP_ prefix. How Apache Handles HTTP Headers Apache's mod_cgi sets environment variables for each HTTP request header received. The variables follow a specific pattern: All header names get an HTTP_ prefix Header names are converted to uppercase Hyphens are replaced with underscores For example, x-client-version: 1.2.3 becomes HTTP_X_CLIENT_VERSION. Reading a Specific Header To read a specific custom header, use os.environ with the converted header ...