完整程式碼：

#!/usr/bin/python
# encoding=utf-8
# Filename: monitorLog.py
# www.jbxue.com

import os
import signal
import subprocess
import time

logFile1 = "test1.log"
logFile2 = 'test2.log'
#日誌檔案一般是按天產生，則通過在程式中判斷檔案的產生日期與當前時間，更換監控的日誌檔案
#程式只是簡單的示例一下，監控test1.log 10秒，轉向監控test2.log
def monitorLog(logFile):
    print '監控的日誌檔案 是%s' % logFile
    # 程式執行10秒，監控另一個日誌
    stoptime = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(time.time() + 10))
    popen = subprocess.Popen('tail -f ' + logFile, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
    pid = popen.pid
    print('Popen.pid:' + str(pid))
    while True:
        line = popen.stdout.readline().strip()
        # 判斷內容是否為空
        if line:
            print(line)
        # 當前時間
        thistime = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(time.time()))
        if thistime >= stoptime:
            # 終止子程序
            popen.kill()
            print '殺死subprocess'
            break
    time.sleep(2)
    monitorLog(logFile2)
if __name__ == '__main__':
    monitorLog(logFile1)