1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3 
   4 """
   5 A simple WSGI CGI gateway taken from:
   6 http://www.python.org/dev/peps/pep-0333/#the-server-gateway-side
   7 (public domain)
   8 """
   9 
  10 
  11 import os, sys
  12 
  13 def run_with_cgi(application):
  14 
  15     environ = dict(os.environ.items())
  16     environ['wsgi.input']        = sys.stdin
  17     environ['wsgi.errors']       = sys.stderr
  18     environ['wsgi.version']      = (1,0)
  19     environ['wsgi.multithread']  = False
  20     environ['wsgi.multiprocess'] = True
  21     environ['wsgi.run_once']    = True
  22 
  23     if environ.get('HTTPS','off') in ('on','1'):
  24         environ['wsgi.url_scheme'] = 'https'
  25     else:
  26         environ['wsgi.url_scheme'] = 'http'
  27 
  28     headers_set = []
  29     headers_sent = []
  30 
  31     def write(data):
  32         if not headers_set:
  33              raise AssertionError("write() before start_response()")
  34 
  35         elif not headers_sent:
  36              # Before the first output, send the stored headers
  37              status, response_headers = headers_sent[:] = headers_set
  38              sys.stdout.write('Status: %s\r\n' % status)
  39              for header in response_headers:
  40                  sys.stdout.write('%s: %s\r\n' % header)
  41              sys.stdout.write('\r\n')
  42 
  43         sys.stdout.write(data)
  44         sys.stdout.flush()
  45 
  46     def start_response(status,response_headers,exc_info=None):
  47         if exc_info:
  48             try:
  49                 if headers_sent:
  50                     # Re-raise original exception if headers sent
  51                     raise exc_info[0], exc_info[1], exc_info[2]
  52             finally:
  53                 exc_info = None     # avoid dangling circular ref
  54         elif headers_set:
  55             raise AssertionError("Headers already set!")
  56 
  57         headers_set[:] = [status,response_headers]
  58         return write
  59 
  60     result = application(environ, start_response)
  61     try:
  62         for data in result:
  63             if data:    # don't send headers until body appears
  64                 write(data)
  65         if not headers_sent:
  66             write('')   # send headers now if body was empty
  67     finally:
  68         if hasattr(result,'close'):
  69             result.close()