September 24, 2010

Python - Linux: Parse Network Stats From ifconfig

I needed to get some Linux networking stats in my Python program today. Specifically, I needed 'bytes sent' and 'bytes received' counts since last reboot from the local machine.

ifconfig is a network configuration utility for Linux that you run from the command line:

corey@studio17:~$ ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:22:19:e5:07:31  
          inet addr:10.0.0.5  Bcast:10.0.0.255  Mask:255.255.255.0
          inet6 addr: fe80::222:19ff:fee5:731/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3353822 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3052408 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3476310326 (3.4 GB)  TX bytes:256706611 (256.7 MB)
          Interrupt:17 

The following function parses output from ifconfig to get the network stats I was after:

import re
import subprocess

def get_network_bytes(interface):
    output = subprocess.Popen(['ifconfig', interface], stdout=subprocess.PIPE).communicate()[0]
    rx_bytes = re.findall('RX bytes:([0-9]*) ', output)[0]
    tx_bytes = re.findall('TX bytes:([0-9]*) ', output)[0]
    return (rx_bytes, tx_bytes)

Example usage:

import re
import subprocess

def main():
    rx_bytes, tx_bytes = get_network_bytes('eth0')
    print '%s bytes received' % rx_bytes
    print '%s bytes sent' % tx_bytes
      
def get_network_bytes(interface):
    output = subprocess.Popen(['ifconfig', interface], stdout=subprocess.PIPE).communicate()[0]
    rx_bytes = re.findall('RX bytes:([0-9]*) ', output)[0]
    tx_bytes = re.findall('TX bytes:([0-9]*) ', output)[0]
    return (rx_bytes, tx_bytes)

if __name__ == '__main__':
    main()

Update: someone left an anonymous comment and mentioned you can just read from proc/net/dev rather than using ifconfig. I modified his code sample and came up with this:

def get_network_bytes(interface):
    for line in open('/proc/net/dev', 'r'):
        if interface in line:
            data = line.split('%s:' % interface)[1].split()
            rx_bytes, tx_bytes = (data[0], data[8])
            return (rx_bytes, tx_bytes)

Example Usage:

def main():
    rx_bytes, tx_bytes = get_network_bytes('eth0')
    print '%s bytes received' % rx_bytes
    print '%s bytes sent' % tx_bytes
      
def get_network_bytes(interface):
    for line in open('/proc/net/dev', 'r'):
        if interface in line:
            data = line.split('%s:' % interface)[1].split()
            rx_bytes, tx_bytes = (data[0], data[8])
            return (rx_bytes, tx_bytes)

if __name__ == '__main__':
    main()

4 comments:

Anonymous said...

assuming you have a proc filesystem it is easier to open /proc/net/dev

no subprocess, no regular expression, nothing


def netstats(device):
device = device + ':'
for line in open("/proc/net/dev", "r"):
data = filter(None,line.split(' '))
if data[0] == device :
return (data[1], data[9])

print netstats("eth0")

EmmEff said...

Agreed. Avoid screen scraping when at all possible!

Obulpathi said...

But the first implementation is much more generic. It can be used with any command.

Rahul Patil said...

Hi,

i think we can get data from :
"/sys/class/net/eth0/statistics/rx_bytes"

and
"/sys/class/net/eth0/statistics/tx_bytes"