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Use Python to find 9 consecutive idle ports

高洛峰

Mar 13, 2017 pm 06:06 PM

This article mainly introduces the method of Python to find 9 consecutive idle ports. Interested friends can refer to it

1. Project requirements

When installing a certain software, you need to fill in the free port during configuration. Check whether a certain port on the 5 platforms is occupied

The 5 platforms are windows, linux, aix, hp, solaris

2. The implementation plan is Two ways

1. Use the

def isInuse(ipList, port):
  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  flag=True
  for ip in ipList:
    try:
      s.connect((ip, int(port)))
      s.shutdown(2)
      print &#39;%d is inuse&#39; % port
      flag=True
      break
    except:
      print &#39;%d is free&#39; % port
      flag=False
  return flag

in the try module if s.connect((ip, int(port))) If it succeeds, it means that the port is occupied.

Otherwise, if connect fails, it will enter except, which means that the port is not occupied.

But there is a problem. In addition to "127.0.0.1" and "0.0.0.0", the port listening IP may also be the local area network IP of the machine such as 222.25.136.17, or the IP of the machine communicating with it.

You can get the LAN ip through this method

def getLocalIp():
  localIP = socket.gethostbyname(socket.gethostname())
  return localIP

This code is only for ipList = ("127.0.0.1" ,"0.0.0.0",getLocalIp()) Connect these 3 IPs

import sys
import os
import socket


def isInuse(ipList, port):
  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  flag=True
  for ip in ipList:
    try:
      s.connect((ip, int(port)))
      s.shutdown(2)
      print &#39;%d is inuse&#39; % port
      flag=True
      break
    except:
      print &#39;%d is free&#39; % port
      flag=False
  return flag


def getLocalIp():
  localIP = socket.gethostbyname(socket.gethostname())
  return localIP

def checkNinePort(startPort):
  flag = True
  ipList = ("127.0.0.1","0.0.0.0",getLocalIp())
  for i in range(1, 10):
    if (isInuse(ipList, startPort)):
      flag = False
      break
    else:
      startPort = startPort + 1
  return flag, startPort


def findPort(startPort):
  while True:
    flag, endPort = checkNinePort(startPort)
    if (flag == True): #ninePort is ok
      break
    else:
      startPort = endPort + 1
  return startPort


def main():
  startPort=51988
  # startPort = int(sys.argv[1])
  print findPort(startPort)

main()

2. Use netstat output information to find the port Number matching

The accuracy of the first method depends on the ip in connect((ip, int(port))). What kind of ip set is complete to ensure that this port is not occupied?

So, there is the following method

**Use netstat -tnpl in Linux to get the port monitoring information,

Observe tcp 0 0 10.173.1.208:3210 0.0.0.0 :* LISTEN 55563/repserver

10.173.1.208:3210 appears, so port 3210 is occupied

Search for this information:5000, if it exists, it means that port 5000 is LISTEN* *.

If the relevant characters of :5000 do not exist in the output result, it means that this port is not occupied.

netstat - tnpl | grep 321

tcp 0 0 10.173.1.208:3211 0.0.0.0:* LISTEN 55563/***
tcp 0 0 0.0.0.0:3212 0.0.0.0:* LISTEN 55586/***
tcp 0 0 10.173.1.208:3213 0.0.0.0:* LISTEN 55707/***
tcp 0 0 0.0.0.0:3214 0.0.0.0:* LISTEN 54272/java
tcp 0 0 0.0.0.0:3215 0.0.0.0:* LISTEN 54272/java
tcp 0 0 10.173.1.208:3216 0.0.0.0:* LISTEN 54822/***
tcp 0 0 10.173.1.208:3217 0.0.0.0:* LISTEN 34959/***
tcp 0 0 10.173.1.208:3218 0.0.0.0:* LISTEN 54849/***

Based on this idea, the code is given.

AIX, HP, WINDOWS, LINUX, and SOLARIS platforms have different ways of viewing port information.

First determine the machine platform

Then call the port occupancy judgment of each platformFunction

If you want to find out the consecutive ports, as long as one port is occupied, jump out of the loop

author = &#39;I316736&#39;
import os
import platform
import sys


def isInuseWindow(port):
  if os.popen(&#39;netstat -an | findstr :&#39; + str(port)).readlines():
    portIsUse = True
    print &#39;%d is inuse&#39; % port
  else:
    portIsUse = False
    print &#39;%d is free&#39; % port
  return portIsUse

def isInuseLinux(port):
  #lsof -i:4906
  #not show pid to avoid complex
  if os.popen(&#39;netstat -na | grep :&#39; + str(port)).readlines():
    portIsUse = True
    print &#39;%d is inuse&#39; % port
  else:
    portIsUse = False
    print &#39;%d is free&#39; % port
  return portIsUse

def isInuseAix(port):
  if os.popen(&#39;netstat -Aan | grep "\.&#39; + str(port) + &#39; "&#39;).readlines():
    portIsUse = True
    print &#39;%d is inuse&#39; % port
  else:
    portIsUse = False
    print &#39;%d is free&#39; % port
  return portIsUse

def isInuseHp(port):
  if os.popen(&#39;netstat -an | grep "\.&#39; + str(port) + &#39; "&#39;).readlines():
    portIsUse = True
    print &#39;%d is inuse&#39; % port
  else:
    portIsUse = False
    print &#39;%d is free&#39; % port
  return portIsUse

def isInuseSun(port):
  if os.popen(&#39;netstat -an | grep "\.&#39; + str(port) + &#39; "&#39;).readlines():
    portIsUse = True
    print &#39;%d is inuse&#39; % port
  else:
    portIsUse = False
    print &#39;%d is free&#39; % port
  return portIsUse

def choosePlatform():
  #&#39;Windows-7-6.1.7601-SP1&#39;
  #&#39;AIX-1-00F739CE4C00-powerpc-32bit&#39;
  #&#39;HP-UX-B.11.31-ia64-32bit&#39;
  #&#39;Linux-3.0.101-0.35-default-x86_64-with-SuSE-11-x86_64&#39;
  #&#39;SunOS-5.10-sun4u-sparc-32bit-ELF&#39;
  machine = platform.platform().lower()
  if &#39;windows-&#39; in machine:
    return isInuseWindow
  elif &#39;linux-&#39; in machine:
    return isInuseLinux
  elif &#39;aix-&#39; in machine:
    return isInuseAix
  elif &#39;hp-&#39; in machine:
    return isInuseHp
  elif &#39;sunos-&#39; in machine:
    return isInuseSun
  else:
    print &#39;Error, sorry, platform is unknown&#39;
    exit(-1)

def checkNinePort(startPort):
  isInuseFun = choosePlatform()
  nineIsFree = True
  for i in range(1, 10):
    if (isInuseFun(startPort)):
      nineIsFree = False
      break
    else:
      startPort = startPort + 1
  return nineIsFree, startPort


def findPort(startPort):
  while True:
    flag, endPort = checkNinePort(startPort)
    if (flag == True): # ninePort is ok
      break
    else:
      startPort = endPort + 1
  return startPort


def main(startPort):
  firstPort=findPort(startPort)
  print &#39;First port of nine free ports is &#39;, firstPort

if name == &#39;main&#39; :
  if len(sys.argv) > 1:
    print len(sys.argv)
    startPort = int(sys.argv[1])
  else:
    startPort = 500
  main(startPort)

##Summary of relevant knowledge points

os.popen()
You can call some shell commands of the system

##os.popen().readlines()
Read the echo information after calling the shell command

 netstat -tnpl 

-tnpl 各个参数的含义
-l或--listening  显示监控中的服务器的Socket。
-n或--numeric  直接使用IP地址，而不通过域名服务器。
-p或--programs  显示正在使用Socket的程序识别码和程序名称。
-t或--tcp  显示TCP传输协议的连线状况

----------

tcp 0 0 10.173.1.208:4903 0.0.0.0:* LISTEN 54849/jsagent
最后的54849/jsagent 表示 进程号 54849 进程名 jsagent

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