port_scanner_00.py

import socket
import termcolor
import sys
from datetime import datetime

remote_server = input("Enter a remote host to scan: ")
remote_serverIP = socket.gethostbyname(remote_server)

def scan(*port):
    t1 = datetime.now()
    start = 0
    end = 65535
    is_port_found = []

    if len(port) == 1:
        end = int(port[0]) + 1
        start = int(port[0])
    elif len(port) == 2:
        start = int(port[0])
        end = int(port[1]) + 1

    try:
        socket.setdefaulttimeout(0.05)

        for port in range(start, end):
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            result = sock.connect_ex((remote_serverIP, port))
            if result == 0:
                text = f"[*] Port {port}"
                space = 18 - len(text)
                f = '{0}: {1:>%d}' % (space)
                termcolor.cprint(f.format(text, "Open"), "green")
                is_port_found.append(True)
            else:
                is_port_found.append(False)
            sock.close()
    except KeyboardInterrupt:
        termcolor.cprint("You pressed Ctrl+C, interrupting process...", "yellow")
        sys.exit()
    except socket.gaierror:
        termcolor.cprint("Hostname could not be resolved. Exiting", "red")
        sys.exit()
    except socket.error:
        termcolor.cprint("Couldn't connect to server. Exiting", "red")
        sys.exit()

    if True not in is_port_found:
        termcolor.cprint("None of the provided ports are open", "red")
    
    t2 = datetime.now()
    print("Scanning Completed in " + str(t2-t1))

def main():
    quit = 0
    while quit == 0:
        print("""Do you want to:
        \t1) Scan one specific port
        \t2) Scan a range of port
        \t3) Scan all ports
        \t4) Exit""")

        user_input = input()
        try:
            user_choice = int(user_input)
        except ValueError:
            termcolor.cprint("You need to choose between options by typing the corresponding number", "white", "on_red")
            continue
        else:
            if user_choice == 1:
                port = input("What port do you want to scan? ")
                if port.isdigit():
                    scan(port)
                    quit = 1
                else:
                    termcolor.cprint("You need to enter a digit to specify your port", "red")
            elif user_choice == 2:
                port1 = input("Specify start: ")
                port2 = input("Specify end: ")
                if port1.isdigit() and port2.isdigit():
                    scan(port1, port2)
                    quit = 1
                else:
                    termcolor.cprint("You need to enter two digits to specify range", "red")
            elif user_choice == 3:
                scan()
                quit = 1
            elif user_choice == 4:
                print("Exiting")
                quit = 1
            else:
                termcolor.cprint("\nYou need to choose between options by typing 1,2 or 3\n", "red")

if __name__ == "__main__":
    main()