Mixin module. It provides the follow functionality groups:
Access to CGI environment variables as methods. See documentation to the CGI class for a list of these variables.
Access to cookies, including the cookies attribute.
Access to parameters, including the params attribute, and overloading
to perform parameter value lookup by key.
The initialize_query method, for initialising the above mechanisms, handling multipart forms, and allowing the class to be used in “offline” mode.
Get the value for the parameter with a given key.
If the parameter has multiple values, only the first will be retrieved; use params() to get the array of values.
 
               # File cgi.rb, line 1165
def [](key)
  params = @params[key]
  return '' unless params
  value = params[0]
  if @multipart
    if value
      return value
    elsif defined? StringIO
      StringIO.new("")
    else
      Tempfile.new("CGI")
    end
  else
    str = if value then value.dup else "" end
    str.extend(Value)
    str.set_params(params)
    str
  end
end
             
            Returns true if a given parameter key exists in the query.
 
               # File cgi.rb, line 1191
def has_key?(*args)
  @params.has_key?(*args)
end