python：搜索stdout文本作爲變量/字符串

Question

我正在使用csv文件來nslookup我的文件的第一列中的每個域。 我正在做的是檢查我的域列表中的域是否與我的服務器匹配。 域的MX記錄是否指向我的服務器？ 域的名稱服務器是否與我的域名服務器相匹配？

現在我有一個安裝類的工作。我搜索標準輸出我的服務器IP /主機/等。如果它們匹配，或者不匹配，我會寫一些東西。

但是，如果MX記錄指向自己的子域，則不足以確定單獨是否是我的IP之一。這是林現在正在做：

如NSLOOKUP：

$ nslookup -type=MX mydomain.com 
Server:  192.168.1.1 
Address: 192.168.1.1#53 

Non-authoritative answer: 
mydomain.com mail exchanger = 10 mail.mydomain.com. 
Authoritative answers can be found from: 
mail.mydomain.com internet address = 1.2.3.4 # << I seem to think this isn't always present. 

當前子域的解決方法：

 elif 'mail.' + row[0] in stdout: 
       host2ip = socket.gethostbyname('mail.' + row[0]) 
       newdata = [host2ip] 
       writer.writerow(row + newdata) 

但是，如果域名使用MX = mail2.mydomain.com或任何其他子域/ A-記錄上述失敗。

最好是使用輸出（mail.domain.com或mail2.mydomain.com或其他）並將其寫入該行（或以前，我將socket.gethostbyname（值））

我沒有設法找到我想要做的另一種方式。在線搜索主要指向使用整個stdout附加。當我想搜索「郵件交換器=」 ###的標準輸出，並使用文本過程使用的MX優先級，或者，mail.mydomain.com

整個Python

#!/usr/bin/python 
# 

import datetime 
import csv 
import os, time 
import socket 
from stat import * # ST_SIZE etc 
from subprocess import Popen, PIPE, STDOUT 

# Set Date 
now = datetime.datetime.now() 
today = now.strftime("%m-%d-%Y") 

# Files 
original = "dns_list.csv" 
results = "results/dns_results_" + today + ".csv" #dns_results_04-14-2012.csv 
tempfile = results + ".tmp" 

# Commands 
mxscan = "nslookup -type=MX" 
nsscan = "nslookup -type=NS" 
ascan = "nslookup -type=A" 
digserver = "8.8.8.8" 
SP = " " 

incsv = open(original, 'rb') 
try: 
    reader = csv.reader(incsv) 

    outcsv = open(tempfile, 'wb') 
    try: 
     writer = csv.writer(outcsv) 

     for row in reader: 
      p = Popen(mxscan + SP + row[0] + SP + digserver, shell=True, stdin=PIPE, stdout=PIPE, stderr=PIPE) 
      stdout, empty = p.communicate() 

      print 'Command: %s\nOutput: %s\n' % (mxscan + SP + row[0] + SP + digserver , stdout) 


      if not stdout or 'find Zone: NXDOMAIN' in stdout: # 'Zone' is column header 
       newdata = ['mail exchange'] 
       writer.writerow(row + newdata) 
      elif 'psmtp.com' in stdout: 
        newdata = ['Postini'] 
        writer.writerow(row + newdata) 
      elif 'mail.' + row[0] in stdout: 
        host2ip = socket.gethostbyname('mail.' + row[0]) 
        newdata = [host2ip] 
        writer.writerow(row + newdata) 
      else: 
       newdata = ['External Email'] 
       writer.writerow(row + newdata) 


    finally: 
     outcsv.close() 
finally: 
    incsv.close() 


original = tempfile 
incsv = open(original, 'rb') 
try: 
    reader = csv.reader(incsv) 
    outcsv = open(results, 'wb') 
    try: 
     writer = csv.writer(outcsv) 

     for row in reader: 
      p = Popen(nsscan + SP + row[0], shell=True, stdin=PIPE,stdout=PIPE, stderr=PIPE) 
      stdout, empty = p.communicate() 

      print 'Command: %s\nOutput: %s\n' % (mxscan + SP + row[0],stdout) 

      if not stdout or 'find Zone: NXDOMAIN' in stdout: 
       newdata = ['A records', 'Action'] 
       writer.writerow(row + newdata) 
      elif 'nameserver = dauth1.mydomain.com' in stdout or 'nameserver = dauth2.mydomain.com' in stdout: 
        newdata = ['dauth1/2'] 
        writer.writerow(row + newdata) 
      elif 'nameserver = ns1.mydomain.com' in stdout or 'nameserver = ns2.mydomain.com' in stdout: 
        newdata = ['ns1/2'] 
        writer.writerow(row + newdata) 
      else: 
       newdata = ['External DNS', 'Delete/Charge'] 
       writer.writerow(row + newdata) 

    finally: 
     outcsv.close() 
finally: 
    incsv.close() 


print "Writing changes to new file...." 
time.sleep(1) 
os.remove(tempfile) 
print "Complete! Your new file is located at /root/mxscan/" + results 

有什麼想法？

Answer 1

這不是回答你解析stdout的問題，但我認爲它會幫助你解決一般問題。

查看dnspython模塊。提供的first example應該有助於您清理MX查詢。

import dns.resolver 

answers = dns.resolver.query('dnspython.org', 'MX') 
for rdata in answers: 
    print 'Host', rdata.exchange, 'has preference', rdata.preference 

然後，您可以執行rdata.exchange查找並將其與屬於您的主機名或IP地址進行比較。

answers = dns.resolver.query(rdata.exchange) 
[a.address for a in answers] 

UPDATE： 不知道爲什麼你會想提高自己NXDOMAIN例外，但這是處理它們的方式。

try: 
    answers = dns.resolver.query('bogus.test.for.nxdomain') 
except dns.resolver.NXDOMAIN: 
    print "NXDOMAIN exception caught." 
else: 
    print "What? Maybe my query is going to a 'helpful' server" \ 
      "that resolves non-existant dns queries to its own server." 
    print "Add a filter for the ip address(s) we just got." 
    print list(answers)