python - 如何以编程方式在 Linux 中查找网络使用情况

Question

我正在尝试通过 python 代码计算 wlan1 接口(interface)上的总网络流量。到目前为止，我尝试了 ethtool、iftop、ifstat、nethogs 但大多数这些工具都显示 ncurses 界面(文本库界面)。

我试过这样的东西

import subprocess
nw_usage = subprocess.Popen(['ifstat', '-i', 'wlan1'])

但它没有给我网络使用值。

我不知道如何从 ncurses 接口(interface)获取单个变量中的网络使用值。 (而且我感觉会有更好的方法来计算网络使用情况)

任何帮助或指导将是一个很大的帮助。

谢谢

Answer 1

我知道这个问题已经有几周了，但也许这个答案仍然有用:)

您可以从/proc/net/dev 中读取设备统计信息。在一个时间间隔内读取发送/接收的字节并计算差值。这是我一起破解的一些简单的 Python 脚本

import re
import time


# A regular expression which separates the interesting fields and saves them in named groups
regexp = r"""
  \s*                     # a interface line  starts with none, one or more whitespaces
  (?P<interface>\w+):\s+  # the name of the interface followed by a colon and spaces
  (?P<rx_bytes>\d+)\s+    # the number of received bytes and one or more whitespaces
  (?P<rx_packets>\d+)\s+  # the number of received packets and one or more whitespaces
  (?P<rx_errors>\d+)\s+   # the number of receive errors and one or more whitespaces
  (?P<rx_drop>\d+)\s+      # the number of dropped rx packets and ...
  (?P<rx_fifo>\d+)\s+      # rx fifo
  (?P<rx_frame>\d+)\s+     # rx frame
  (?P<rx_compr>\d+)\s+     # rx compressed
  (?P<rx_multicast>\d+)\s+ # rx multicast
  (?P<tx_bytes>\d+)\s+    # the number of transmitted bytes and one or more whitespaces
  (?P<tx_packets>\d+)\s+  # the number of transmitted packets and one or more whitespaces
  (?P<tx_errors>\d+)\s+   # the number of transmit errors and one or more whitespaces
  (?P<tx_drop>\d+)\s+      # the number of dropped tx packets and ...
  (?P<tx_fifo>\d+)\s+      # tx fifo
  (?P<tx_frame>\d+)\s+     # tx frame
  (?P<tx_compr>\d+)\s+     # tx compressed
  (?P<tx_multicast>\d+)\s* # tx multicast
"""


pattern = re.compile(regexp, re.VERBOSE)


def get_bytes(interface_name):
    '''returns tuple of (rx_bytes, tx_bytes) '''
    with open('/proc/net/dev', 'r') as f:
        a = f.readline()
        while(a):
            m = pattern.search(a)
            # the regexp matched
            # look for the needed interface and return the rx_bytes and tx_bytes
            if m:
                if m.group('interface') == interface_name:
                    return (m.group('rx_bytes'),m.group('tx_bytes'))
            a = f.readline()


while True:
    last_time  = time.time()
    last_bytes = get_bytes('wlan0')
    time.sleep(1)
    now_bytes = get_bytes('wlan0')
    print "rx: %s B/s, tx %s B/s" % (int(now_bytes[0]) - int(last_bytes[0]), int(now_bytes[1]) - int(last_bytes[1]))