从python中执行的命令'host'获取IP

Question

I have this function to show me the 1st ip of a domain:

def get_ip_address(url):
    command="host "+url
    process=os.popen(command)
    results=str(process.read()) 
    marker=results.find('has address')+12   
    print results[marker:].splitlines()[0]
    return results[marker:].splitlines()[0]

But this only shows me the first ip. I'd like to show only the ip's. The marker is for not having "has address" as shown below (imagine I input "reddit.com":

['151.101.65.140', 'reddit.com has address 151.101.129.140', 'reddit.com has address 151.101.193.140', 'reddit.com has address 151.101.1.140', 'reddit.com mail is handled by 1 aspmx.l.google.com.', 'reddit.com mail is handled by 10 aspmx2.googlemail.com.', 'reddit.com mail is handled by 10 aspmx3.googlemail.com.', 'reddit.com mail is handled by 5 alt1.aspmx.l.google.com.', 'reddit.com mail is handled by 5 alt2.aspmx.l.google.com.']

I want to show only the ips, not reddit.com has address nor once the ip's end, mail is handled etc.

I tried with

def get_ip_address(url):
    command="host "+url
    process=os.popen(command)
    results=str(process.read()) 
    marker=results.find('has address')+12
    i=0
    arrayIps=[]
    while "has address" in results[marker:].splitlines()[i]:

        print results[marker:].splitlines()[i]
        arrayIps.append(results[marker:].splitlines()[i])
        print("array")
        print arrayIps[i]
        i=i+1
    return arrayIps

But it is not working! Not even returning anything useful!

What I am expecting is an array with (in this case):

'151.101.65.140', '151.101.129.140', '151.101.193.140', '151.101.1.140'

Answer 1

See it shows multiple hosts as you required .Your output can be generated using a map function

In [132]: socket.getaddrinfo("reddit.com", 80, proto=socket.IPPROTO_TCP)
Out[132]: 
[(<AddressFamily.AF_INET: 2>,
  <SocketKind.SOCK_STREAM: 1>,
  6,
  '',
  ('151.101.65.140', 80)),
 (<AddressFamily.AF_INET: 2>,
  <SocketKind.SOCK_STREAM: 1>,
  6,
  '',
  ('151.101.1.140', 80)),
 (<AddressFamily.AF_INET: 2>,
  <SocketKind.SOCK_STREAM: 1>,
  6,
  '',
  ('151.101.129.140', 80)),
 (<AddressFamily.AF_INET: 2>,
  <SocketKind.SOCK_STREAM: 1>,
  6,
  '',
  ('151.101.193.140', 80))]


In [134]: list(map(lambda x:x[4][0],socket.getaddrinfo("reddit.com", 80, proto=socket.IPPROTO_TCP)))
Out[134]: ['151.101.129.140', '151.101.193.140', '151.101.65.140', '151.101.1.140']

Answer 2

You should try the dig command instead of host and apply a proper regexp aswell:

from subprocess import run, PIPE

def get_answer(url):
    response = run(["dig", "+noall", "+answer", "+short","{url}".format(url=url)], stdout=PIPE, universal_newlines=True)
    return response.stdout

Notes:

• The run's parameter may vary depends on why python version you are, this is an example for python 3.5: https://docs.python.org/3.5/library/subprocess.html
• You should adapt this code to some border cases.

EDIT

As mentioned in commentaries, you can rid off the regex part using +short option in dig.

Answer 3

Try splitting the string IPs at their spaces using .split() and then taking the last item of it [-1] and then splitting the last item (which should be an IP address) at the periods .split('.') . Join the strings returned from that using ''.join(iterable) where iterable are the value from .split('.') . Check if the joined string is a numeric value using .isnumeric() and if that is True, print and return the last item.

def get_ip_address(url):
    command="host "+url
    process=os.popen(command)
    results=str(process.read())
    marker=results.find('has address')+12
    ip_list=[]
    for ip in results[marker:].splitlines()[0]:
        if ''.join(ip.split()[-1].split('.')).isnumeric():
            ip_list.append(ip.split()[-1])
    print ip_list
    return ip_list

The bad news is that I can't seem to get results=str(process.read()) to be set to anything. It currently just returns an empty string, but hopefully, you'll have more luck :D

(Edit: As said in your comments, socket.getaddrinfo() works with flying colours. Not sure of it on Python 2.7, but it works here in 3.7.1)

(Edit2: Here's your code in 3.7.1. Should be similar in 2.7)

import socket
ip_list = []
for info in socket.getaddrinfo('reddit.com', 80):
    ip_list.append(info[-1][0])