无法从文件 ping 多个 IP 地址

Question

I have a file ip.txt file which contains a list of IP addresses. I want to ping each address in the file and repeat this forever. But my script only pings the address contained in the last line (see output below). How can I modify my script to fix this?

import cmd
import time
import sys
import os

my_file = open("ip.txt","rb")
for line in my_file:
        l = [i.strip() for i in line.split(' ')]
        IP = l[0]

def Main():

    while True:
        ping = os.system("ping", "-c", "1", "-n", "-W", "2", IP)
        if ping:
            print IP 'no connection'
            CT =time.strftime("%H:%M:%S %d/%m/%y")
            alert=' No Connection'
            with open('logfile.txt','a+') as f:
                f.write('\n'+CT)
                f.write(alert)

        time.sleep(4)

if __name__ == "__main__":
    Main()

Output:

[root@localhost PythonScript]# python pingloop.py
PING 192.168.1.100 (192.168.1.100) 56(84) bytes of data.
64 bytes from 192.168.1.100: icmp_seq=1 ttl=128 time=0.655 ms
64 bytes from 192.168.1.100: icmp_seq=2 ttl=128 time=1.15 ms
64 bytes from 192.168.1.100: icmp_seq=3 ttl=128 time=1.14 ms
64 bytes from 192.168.1.100: icmp_seq=4 ttl=128 time=0.529 ms
64 bytes from 192.168.1.100: icmp_seq=5 ttl=128 time=0.538 ms

--- 192.168.1.100 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 0.529/0.805/1.156/0.287 ms
PING 192.168.1.100 (192.168.1.100) 56(84) bytes of data.
64 bytes from 192.168.1.100: icmp_seq=1 ttl=128 time=0.476 ms
64 bytes from 192.168.1.100: icmp_seq=2 ttl=128 time=0.416 ms
64 bytes from 192.168.1.100: icmp_seq=3 ttl=128 time=0.471 ms
64 bytes from 192.168.1.100: icmp_seq=4 ttl=128 time=0.478 ms
64 bytes from 192.168.1.100: icmp_seq=5 ttl=128 time=0.574 ms

ip.txt file:

192.168.1.91
192.168.1.92
192.168.1.93
192.168.1.94
192.168.1.95
192.168.1.96
192.168.1.97
192.168.1.98
192.168.1.99
192.168.1.100

Answer 1

for line in my_file: l = [i.strip() for i in line.split(' ')] IP = l[0]

Here you overwrite the previously read IP address with the new address in each iteration. So in the end, as you observed, you only have the last address.

Instead, build a list of addresses:

addresses = []
for line in my_file:
    IP = line.split()[0].strip()
    addresses.append(IP)

or simply

addresses = [line.split()[0].strip() for line in my_file]

Later, you have to add an additional loop over the list of addresses. Instead of:

 while True: ping = os.system("ping", "-c", "1", "-n", "-W", "2", IP) # etc.

do

while True:
    for IP in addresses:
        ping = os.system("ping", "-c", "1", "-n", "-W", "2", IP)
        # etc.

Answer 2

Define IP as a global list variable and add all ip addresses to this list then iterate over the list:

IP = []
for line in my_file: 
    l = [i.strip() for i in line.split(' ')] 
    IP.append(l[0])

# instead while use for 
for ip in IP: 
    ping = os.system("ping", "-c", "1", "-n", "-W", "2", ip)
    ...