Como resolver o DNS em Python?

Question

Eu tenho um script DNS que permite aos usuários resolver os nomes DNS digitando nomes de sites em um prompt de comando do Windows.

Eu olhei através de vários guias na resolução do DNS, mas meu script ainda não consegue resolver os nomes (www.google.com) ou (google.com) para o endereço IP.

O script gera um erro de

Traceback (most recent call last):
  File "C:\python\main_menu.py", line 37, in ?
    execfile('C:\python\showdns.py')
  File "C:\python\showdns.py", line 3, in ?
    x = input ("\nPlease enter a domain name that you wish to translate: ")
  File "<string>", line 0, in ?
NameError: name 'google' is not defined

O código:

import socket

x = input ("\nPlease enter a domain name that you wish to translate: ")

print ("\n\nThe IP Address of the Domain Name is: "+socket.gethostbyname_ex(x))

x = raw_input("\nSelect enter to proceed back to Main Menu\n")
if x == '1': 
execfile('C:\python\main_menu.py')

Por favor, dê conselhos sobre os códigos. Obrigado!

Answer 1

input () é a função errada a ser usada aqui. Na verdade, ele avalia a string que o usuário inseriu.

Também Gethostbyname_ex Retorna mais do que apenas uma string. Portanto, sua declaração de impressão também falharia.

No seu caso, este código deve funcionar:

import socket

x = raw_input ("\nPlease enter a domain name that you wish to translate: ")  

data = socket.gethostbyname_ex(x)
print ("\n\nThe IP Address of the Domain Name is: "+repr(data))  

x = raw_input("\nSelect enter to proceed back to Main Menu\n")  
if x == '1':   
    execfile('C:\python\main_menu.py')  

Answer 2

#!/user/bin/env python
"""
Resolve the DNS/IP address of a given domain
data returned is in the format:
(name, aliaslist, addresslist)
@filename resolveDNS.py
@version 1.01 (python ver 2.7.3)
@author LoanWolffe
"""
import socket

def getIP(d):
    """
    This method returns the first IP address string
    that responds as the given domain name
    """
    try:
        data = socket.gethostbyname(d)
        ip = repr(data)
        return ip
    except Exception:
        # fail gracefully!
        return False
#
def getIPx(d):
    """
    This method returns an array containing
    one or more IP address strings that respond
    as the given domain name
    """
    try:
        data = socket.gethostbyname_ex(d)
        ipx = repr(data[2])
        return ipx
    except Exception:
        # fail gracefully!
        return False
#
def getHost(ip):
    """
    This method returns the 'True Host' name for a
    given IP address
    """
    try:
        data = socket.gethostbyaddr(ip)
        host = repr(data[0])
        return host
    except Exception:
        # fail gracefully
        return False
#
def getAlias(d):
    """
    This method returns an array containing
    a list of aliases for the given domain
    """
    try:
        data = socket.gethostbyname_ex(d)
        alias = repr(data[1])
        #print repr(data)
        return alias
    except Exception:
        # fail gracefully
        return False
#

# test it

x = raw_input("Domain name or IP address? > ")


a = getIP(x)
b = getIPx(x)
c = getHost(x)
d = getAlias(x)

print " IP ", a
print " IPx ", b
print " Host ", c
print " Alias ", d

Answer 3

Usar raw_input ao invés de input.