20.20. CGIHTTPServer — CGI-capable HTTP request handler


The CGIHTTPServer module has been merged into http.server in Python 3. The 2to3 tool will automatically adapt imports when converting your sources to Python 3.

The CGIHTTPServer module defines a request-handler class, interface compatible with BaseHTTPServer.BaseHTTPRequestHandler and inherits behavior from SimpleHTTPServer.SimpleHTTPRequestHandler but can also run CGI scripts.


This module can run CGI scripts on Unix and Windows systems.


CGI scripts run by the CGIHTTPRequestHandler class cannot execute redirects (HTTP code 302), because code 200 (script output follows) is sent prior to execution of the CGI script. This pre-empts the status code.

The CGIHTTPServer module defines the following class:

class CGIHTTPServer.CGIHTTPRequestHandler(request, client_address, server)

This class is used to serve either files or output of CGI scripts from the current directory and below. Note that mapping HTTP hierarchic structure to local directory structure is exactly as in SimpleHTTPServer.SimpleHTTPRequestHandler.

The class will however, run the CGI script, instead of serving it as a file, if it guesses it to be a CGI script. Only directory-based CGI are used — the other common server configuration is to treat special extensions as denoting CGI scripts.

The do_GET() and do_HEAD() functions are modified to run CGI scripts and serve the output, instead of serving files, if the request leads to somewhere below the cgi_directories path.

The CGIHTTPRequestHandler defines the following data member:


This defaults to ['/cgi-bin', '/htbin'] and describes directories to treat as containing CGI scripts.

The CGIHTTPRequestHandler defines the following methods:


This method serves the 'POST' request type, only allowed for CGI scripts. Error 501, “Can only POST to CGI scripts”, is output when trying to POST to a non-CGI url.

Note that CGI scripts will be run with UID of user nobody, for security reasons. Problems with the CGI script will be translated to error 403.

For example usage, see the implementation of the test() function.

See also

Module BaseHTTPServer
Base class implementation for Web server and request handler.

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