Pinging a list of hosts

Question

I have a simple script that will take a list of hosts and ping each host (there's about 200) a single time before moving on. This is not the most effecient method I am sure, as it is very linear. And it takes a few minutes to complete. I would ideally like to run this script every minute (so each IP address is checked every minute (the actual running of the script is controlled externally).

I was looking for some pointers on potentially making the script more effecient/dynamic.

import sys
import os
import platform
import subprocess

plat = platform.system()
scriptDir = sys.path[0]
hosts = os.path.join(scriptDir, 'hosts.txt')
hostsFile = open(hosts, "r")
lines = hostsFile.readlines()
if plat == "Windows":
    for line in lines:
        line = line.strip( )
        ping = subprocess.Popen(
            ["ping", "-n", "1", "-l", "1", "-w", "100", line],
            stdout = subprocess.PIPE,
            stderr = subprocess.PIPE
        )
        out, error = ping.communicate()
        print out
        print error

if plat == "Linux":
    for line in lines:
        line = line.strip( )
        ping = subprocess.Popen(
            ["ping", "-c", "1", "-l", "1", "-s", "1", "-W", "1", line],
            stdout = subprocess.PIPE,
            stderr = subprocess.PIPE
        )
        out, error = ping.communicate()
        print out
        print error

hostsFile.close()

Answer 1

Here's a solution using threads:

import sys
import os
import platform
import subprocess
import Queue
import threading

def worker_func(pingArgs, pending, done):
    try:
        while True:
            # Get the next address to ping.
            address = pending.get_nowait()

            ping = subprocess.Popen(ping_args + [address],
                stdout = subprocess.PIPE,
                stderr = subprocess.PIPE
            )
            out, error = ping.communicate()

            # Output the result to the 'done' queue.
            done.put((out, error))
    except Queue.Empty:
        # No more addresses.
        pass
    finally:
        # Tell the main thread that a worker is about to terminate.
        done.put(None)

# The number of workers.
NUM_WORKERS = 4

plat = platform.system()
scriptDir = sys.path[0]
hosts = os.path.join(scriptDir, 'hosts.txt')

# The arguments for the 'ping', excluding the address.
if plat == "Windows":
    pingArgs = ["ping", "-n", "1", "-l", "1", "-w", "100"]
elif plat == "Linux":
    pingArgs = ["ping", "-c", "1", "-l", "1", "-s", "1", "-W", "1"]
else:
    raise ValueError("Unknown platform")

# The queue of addresses to ping.
pending = Queue.Queue()

# The queue of results.
done = Queue.Queue()

# Create all the workers.
workers = []
for _ in range(NUM_WORKERS):
    workers.append(threading.Thread(target=worker_func, args=(pingArgs, pending, done)))

# Put all the addresses into the 'pending' queue.
with open(hosts, "r") as hostsFile:
    for line in hostsFile:
        pending.put(line.strip())

# Start all the workers.
for w in workers:
    w.daemon = True
    w.start()

# Print out the results as they arrive.
numTerminated = 0
while numTerminated < NUM_WORKERS:
    result = done.get()
    if result is None:
        # A worker is about to terminate.
        numTerminated += 1
    else:
        print result[0] # out
        print result[1] # error

# Wait for all the workers to terminate.
for w in workers:
    w.join()

Answer 2

It's not a complete answer, but your code would be more clear (and easy to maintain) if you won't duplicate code:

import sys
import os
import platform
import subprocess

plat = platform.system()
scriptDir = sys.path[0]
hosts = os.path.join(scriptDir, 'hosts.txt')
hostsFile = open(hosts, "r")
lines = hostsFile.readlines()
for line in lines:
    line = line.strip( )
    if plat == "Windows":
        args = ["ping", "-n", "1", "-l", "1", "-w", "100", line]

    elif plat == "Linux":
        args = ["ping", "-c", "1", "-l", "1", "-s", "1", "-W", "1", line]

    ping = subprocess.Popen(
        args,
        stdout = subprocess.PIPE,
        stderr = subprocess.PIPE
    )
    out, error = ping.communicate()
    print out
    print error

hostsFile.close()

Answer 3

Why not using threads ? You could run your pings simultaneously.

This works quite well :

import sys
import os
import platform
import subprocess
import threading

plat = platform.system()
scriptDir = sys.path[0]
hosts = os.path.join(scriptDir, 'hosts.txt')
hostsFile = open(hosts, "r")
lines = hostsFile.readlines()

def ping(ip):
    if plat == "Windows":
        ping = subprocess.Popen(
            ["ping", "-n", "1", "-l", "1", "-w", "100", ip],
            stdout = subprocess.PIPE,
            stderr = subprocess.PIPE
        )

    if plat == "Linux":
        ping = subprocess.Popen(
            ["ping", "-c", "1", "-l", "1", "-s", "1", "-W", "1", ip],
            stdout = subprocess.PIPE,
            stderr = subprocess.PIPE
        )

    out, error = ping.communicate()
    print out
    print error

for ip in lines:
    threading.Thread(target=ping, args=(ip,)).run()

Answer 4

i would look into the python-nmap package.

why reinvent the wheel if there is already one free to use? You will be much more productive and flexible this way.

to check for hosts active in an ipv4 network you would usually do a:

nmap -sP 192.168.100.0/24 

which basically does a ping and takes in most cicumstances 2-5 sec.

nmap is also avaiable for windows.