FUNCTIONS
- Set of instructions to carry out a task.
- Can take input, and return a result.
- Make the code clearer, reusable, and more abstract.
- input() function prompts the user to enter the value.
Rewrite the Python script using the function style.
#!/usr/bin/env python import subprocess
import optparse def change_mac(interface, new_mac):
print("[+] Changing MAC address for " + interface + " to " + new_mac)
subprocess.call(["ifconfig", interface, "down"])
subprocess.call(["ifconfig", interface, "hw", "ether", new_mac])
subprocess.call(["ifconfig", interface, "up"]) parser = optparse.OptionParser() parser.add_option("-i", "--interface", dest="interface", help="Interface to change its MAC address")
parser.add_option("-m", "--mac", dest="new_mac", help="New MAC address") (options, arguments) = parser.parse_args() change_mac(options.interface, options.new_mac)
Execute the following commands successfully to change the MAC.
python mac_changer.py -i eth0 -m :::::
Rewrite the Python script.
#!/usr/bin/env python import subprocess
import optparse def get_arguments():
parser = optparse.OptionParser()
parser.add_option("-i", "--interface", dest="interface", help="Interface to change its MAC address")
parser.add_option("-m", "--mac", dest="new_mac", help="New MAC address")
return parser.parse_args() def change_mac(interface, new_mac):
print("[+] Changing MAC address for " + interface + " to " + new_mac)
subprocess.call(["ifconfig", interface, "down"])
subprocess.call(["ifconfig", interface, "hw", "ether", new_mac])
subprocess.call(["ifconfig", interface, "up"]) (options, arguments) = get_arguments()
change_mac(options.interface, options.new_mac)
Execute the following commands successfully to change the MAC.
python mac_changer.py -i eth0 -m :::::33
Decision Making
- Execute code ONLY if a condition is true.
Rewrite the Python code using conditional statements.
#!/usr/bin/env python import subprocess
import optparse def get_arguments():
parser = optparse.OptionParser()
parser.add_option("-i", "--interface", dest="interface", help="Interface to change its MAC address")
parser.add_option("-m", "--mac", dest="new_mac", help="New MAC address")
(options, arguments) = parser.parse_args()
if not options.interface:
parser.error("[-] Please specify an interface, use --help for more info.")
elif not options.new_mac:
parser.error("[-] Please specify a new mac, use --help for more info.")
return options def change_mac(interface, new_mac):
print("[+] Changing MAC address for " + interface + " to " + new_mac)
subprocess.call(["ifconfig", interface, "down"])
subprocess.call(["ifconfig", interface, "hw", "ether", new_mac])
subprocess.call(["ifconfig", interface, "up"]) options = get_arguments()
change_mac(options.interface, options.new_mac)
Test the script using the following commands.