python措施挪用tcpdump举办阐明抓包过滤-系统配置-梦飞vps服务器租用

之前在linux用python剧本写一个抓包阐明小东西，实在不想用什么libpcap、pypcap所以，简朴来了个tcpdump加grep搞定。根基思路是别离起tcpdump和grep两个历程，历程直接通过pipe互换数据，简朴

#! /usr/bin/python
def tcpdump():
        import subprocess, fcntl, os
        # sudo tcpdump -i eth0 -n -s 0 -w - | grep -a -o -E "Host: .*|GET /.*"
        cmd1 = ['tcpdump', '-i', 'eth0', '-n','-B', '4096','-s', '0', '-w', '-']
        cmd2 = ['grep', '--line-buffered', '-a', '-o', '-E', 'Host: .*|GET /.*']
        p1 = subprocess.Popen(cmd1, stdout=subprocess.PIPE)
        p2 = subprocess.Popen(cmd2, stdout=subprocess.PIPE, stdin=p1.stdout)
        flags = fcntl.fcntl(p2.stdout.fileno(), fcntl.F_GETFL)
        fcntl.fcntl(p2.stdout.fileno(), fcntl.F_SETFL, (flags | os.O_NDELAY | os.O_NONBLOCK))
        return p2
def poll_tcpdump(proc):
        #print 'poll_tcpdump....'
        import select
        txt = None
        while True:
                # wait 1/10 second
                readReady, _, _ = select.select([proc.stdout.fileno()], [], [], 0.1)
                if not len(readReady):
                        break
                try:
                        for line in iter(proc.stdout.readline, ""):
                                if txt is None:
                                        txt = ''
                                txt += line
                except IOError:
                        print 'data empty...'
                        pass
                break
        return txt
proc = tcpdump()
while True:
        text = poll_tcpdump(proc)
        if text:
                print '>>>> ' + text