无法从python程序中获取缩进输出

Question

我正在编写一个脚本来捕获给定接口的流量。但在执行程序时，我得到的消息是：

"Process finished with exit code 0"

请注意下面我的代码：

import socket
from struct import *
import datetime
import pcapy
import sys


def main(argv):
    devices = pcapy.findalldevs()
    print (devices)

    for d in devices:
        print "Available devices are ", d

    #Device to be sniffed

    input_dev = raw_input("Enter deice name to sniff")

    print "Following device would be printed", input_dev

    #open
    #device
    # Arguments here are:
    #   device
    #   snaplen (maximum number of bytes to capture _per_packet_)
    #   promiscious mode (1 for true)
    #   timeout (in milliseconds)


    cap = pcapy.open_live(input_dev,65536,1,0)

    #Interating all packets captured in to a variable
    while(1):
        (header, packet) = cap.next()
        parse_packet(packet)

        #Convert a string of 6 characters of ethernet address into a dash separated hex string
    def  eth_addr(a):
        b = "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x" % (ord(a[0]), ord(a[1]), ord(a[2]), ord(a[3]), ord(a[4]), ord(a[5]))


    # Parsing captured packets

    def parse_packet(packet):

        eth_length = 14

        # Get the protocol used from the captured packet
        eth_header = packet[:eth_length]
        eth = unpack('!6s6sH', eth_header)
        eth_protocol = socket.ntohs(eth[2])
        print 'Destination MAC : ' + eth_addr(packet[0:6])+'Source MAC: ' + eth_addr(packet[0:12]) + 'Protocol: ' +str(eth_protocol)

        # Parse the IP packet
        #
        if eth_protocol == 8:
         #Parse IP header
        #take first 20 characters for the ip header
           ip_header = packet[eth_length:20+eth_length]

        #Now unpack them
        iph = unpack('!BBHHHBBH4s4s', ip_header)
        version_ihl = iph[0]
        version = version_ihl >> 4
        ihl = version_ihl & oxf # need to know what is the oxf
        iph_length = ihl * 4

        ttl = iph[5]
        print "ttl value is = ", str(ttl)

        protocol =  ip[6]
        print "protocol = ", str(protocol)

        s_addr = socket.inet_ntoa(iph[8]);
        print "source address = ", str(s_addr)

        d_address = socket.inet_ntoa(iph[9])
        print "Destination address = ", str(d_address)


        #Parsing TCP header

        if protocol == 6:

            #if protocol = 6, it would be TCP
            t = iph_length + eth_length
            tcp_heder = packet

            #Unpack the packet
            tcph = unpack('!HHLLBBHHH', tcp_heder)

            source_port = tcph[0]
            print "Source port =", source_port

            dst_port = tcph[1]
            print "Dst port =", dst_port

            ack_no = tcph[3]
            print "ack_No = ", ack_no

            doff_deserverved = tcph[4]
            print "doff_deserved = ", doff_deserverved
            tcp_length = doff_deserverved >> 4

            h_size = eth_length + iph_length + tcp_length * 4
            data_size = len(packet) - h_size

            #get the data from the packet
            data = packet[data_size:]
            print "Data is = ", data

        elif protocol == 1:
            u = iph_length + eth_length
            icmp_length = 4
            icmp_header= packet[u:u+4]

            #Now unpack them
            icmp = unpack('!BBH' , icmp_header)

            icmp_type = icmp[0]
            print "Type is = ", icmp

            code = icmp[1]
            print "Code is = ", code

            checkSum = icmp[3]
            print "Check sum is ", checkSum

            h_size = eth_length + iph_length + icmp_length
            data_sze = len(packet)- h_size
            print "Data size = ", data_size

            #Get Data from the packet
            data2 = packet[h_size:]
            print "Data is = ", data2


         #Parsing UDP packet
        elif protocol == 17:
            u = iph_length + eth_length
            udph_leungth = 8
            udp_header = packet[u:u+8]

            #Now unpack them
            udp_packet = unpack('!HHHH', udp_header)

            s_port = udp_packet[0]
            print "Source Port = ", s_port

            d_port = udp_packet[1]
            print "Udp Packet = ", d_port


            lenth_of_packet = udp_packet[2]
            print "Length of packet = ", lenth_of_packet

            check_sum = udp_packet[3]
            print "check sum is ", check_sum

            h_size_of_packet = eth_length + iph_length + udph_leungth

            actaul_size = len(packet) - h_size_of_packet

            #Retrieving data packet from the size

            data = packet[h_size_of_packet]

            print "Actual Data = ", data

            #IF there any other some protocol
        else:
            print "Protol other than TCP/UDP/ICMP"



    main(sys.argv)

请让我知道什么是不产生缩进输出或任何其他方式获得相同的原因。

Answer 1

您的代码中存在多个缩进问题。我建议你重温一下你的代码。