HTTPHeaderScanner.py

import urllib2
import sys


class HttpHeaderScanner:

    def __init__(self):
        """Constructor of the class

        """
        self.__headers = {}

    def connect_server(self, website):
        """Connect a server of which the header fields we want to check

        Args:
            website (String):
                The website whose server we want to check
        """
        req = urllib2.Request(website)

        try:
            response = urllib2.urlopen(req)

            info = response.info()
            info_list = info.items()

            for ele in info_list:
                self.__headers[ele[0]] = ele[1]

        except IOError as e:

            print('Warning: Connection Error!!!')
            print(e)
            raise sys.exc_info()[0], sys.exc_info()[1], sys.exc_info()[2]

    def get_server_field(self):
        """Return the server fields in the HTTP header

        Returns:
            server (String):
                The value of the server field, if not exists, return "None".
        """

        server = ''
        if len(self.__headers) == 0:
            server = 'None'
        elif 'server' in self.__headers:
            server = self.__headers['server']
        else:
            server = 'None'

        return server

    def show_headers(self):
        """Print out all the fields of the http header

        """
        if len(self.__headers) == 0:
            print('Connection Error')
        for ele in self.__headers:
            print(str(ele) + ': ' + str(self.__headers[ele]) + '\n')

    def get_headers(self):
        """Return a dictionary of headers fields in (fieldname, value) pair

        Returns:
            tmp (dict): A dictionary of (field name, corresponding value) pairs
        """
        tmp = dict()
        if len(self.__headers) == 0:
            return tmp

        for key in self.__headers:
            tmp[key] = self.__headers[key]

        return tmp

    def get_header_count(self):
        """Return the total number of different fields in the header

        Returns:
            header_count (int):
                number of the header fields.
                If connection error occured, return -1
        """
        header_count = 0
        if len(self.__headers) == 0:
            header_count = -1
        else:
            header_count = len(self.__headers)
        return header_count