Python, who is calling my python module

Question

I have one Python module that can be called by a CGI script (passing it information from a form) or from the command line (passing it options and arguments from the command line). Is there a way to establish if the module has been called from the CGI script or from the command line ??

Answer 1

This will do it:

import os
if os.environ.has_key('REQUEST_METHOD'):
    # You're being run as a CGI script.
else:
    # You're being run from the command line.

Answer 2

This is a really bad design idea. Your script should be designed to work independently of how it's called. The calling programs should provide a uniform environment.

You'll be happiest if you design your scripts to work in exactly one consistent way. Build things like this.

• myscript.py - the "real work" - defined in functions and classes.

• myscript_cgi.py - a CGI interface that imports myscript and uses the classes and functions.

• myscript_cli.py - the command-line interface that parses the command-line options, imports myscript, and uses the classes and functions.

A single script that does all three things (real work, cgi interface, cli interface) is usually a mistake.