Question

Write regular expressions that will match IP addresses and usernames in a Microsoft IIS log file.

First, you will write a regular expression that matches IP addresses within the re.compile function call on line 36. Next, you will write a regular expression that matches usernames (in the format domain\username) on line 50. Finally, in steps 3 and 4 you will write a loop for each step that displays all the IP addresses (gathered into the list ipAddresses) and usernames (gathered in the list list users) to the console window.

# Import the regular expressions module

import re

# Function that takes a file and loads it into

# a Python list variable and returns that variable

def loadLogIntoList(filename):

   with open(filename) as f:

      lines = f.read().splitlines()

   return lines

# Ask the user to input a file name

filename = input("Type in the filename for the log to analyze: ")

# Load each line of the file into a list of strings

lines = loadLogIntoList(filename)

# Create a placeholder variable (a list of strings) to

# hold the IP addresses and users we find in the log file

ipAddresses = []

users = []

# Loop through each line of the file

for line in lines:

   ####  Part 1: Create a new python regular expression object

   ####          by compiling an expression to look for an

   ####          IP address

  

   ipRegEx = re.compile(r'REPLACE WITH A REGULAR EXPRESSION')

   

   # Search the contents of each line for a match. If there is a

   # match and that match doesn't already exist in the list, append

   # it to the list

   ipSearchResult = ipRegEx.search(line)

   if ipSearchResult != None and ipSearchResult.group() not in ipAddresses:

      ipAddresses.append(ipSearchResult.group())

      

   ####  Part 2: Create a new python regular expression object

   ####          by compiling an expression to look for a user

   ####          account(as a DOMAIN\username combination)

   userRegEx = re.compile(r'REPLACE WITH A REGULAR EXPRESSION')

   

   # Search the contents of each line for a match. If there is a

   # match and that match doesn't already exist in the list, append

   # it to the list

   userSearchResult = userRegEx.search(line)

   if userSearchResult != None and userSearchResult.group() not in users:

      users.append(userSearchResult.group())

####  Part 3: Loop through each IP address and display

####          each IP address found to the user

# WRITE CODE HERE

   

####  Part 4: Loop through each username (shown as a

####          DOMAIN\username combination) to the user

# WRITE CODE HERE

Answer 1

def isPhoneNumber(text):
❶     if len(text) != 12:
           return False
       for i in range(0, 3):
❷         if not text[i].isdecimal():
               return False
❸     if text[3] != '-':
           return False
       for i in range(4, 7):
❹         if not text[i].isdecimal():
               return False
❺     if text[7] != '-':
           return False
       for i in range(8, 12):
❻         if not text[i].isdecimal():
               return False
❼     return True

   print('415-555-4242 is a phone number:')
   print(isPhoneNumber('415-555-4242'))
   print('Moshi moshi is a phone number:')
   print(isPhoneNumber('Moshi moshi'))