python实现ping的方法

本文实例讲述了python实现ping的方法。分享给大家供大家参考。具体如下：

    #!/usr/bin/env python
    #coding:utf-8
    import os, sys, socket, struct, select, time
    # From /usr/include/linux/icmp.h; your milage may vary.
    ICMP_ECHO_REQUEST = 8 # Seems to be the same on Solaris.
    def checksum(source_string):
      """
      I'm not too confident that this is right but testing seems
      to suggest that it gives the same answers as in_cksum in ping.c
      """
      sum = 0
      countTo = (len(source_string)/2)*2
      count = 0
      while count<countTo:
        thisVal = ord(source_string[count + 1])*256 + ord(source_string[count])
        sum = sum + thisVal
        sum = sum & 0xffffffff # Necessary?
        count = count + 2
      if countTo<len(source_string):
        sum = sum + ord(source_string[len(source_string) - 1])
        sum = sum & 0xffffffff # Necessary?
      sum = (sum >> 16) + (sum & 0xffff)
      sum = sum + (sum >> 16)
      answer = ~sum
      answer = answer & 0xffff
      # Swap bytes. Bugger me if I know why.
      answer = answer >> 8 | (answer << 8 & 0xff00)
      return answer
    def receive_one_ping(my_socket, ID, timeout):
      """
      receive the ping from the socket.
      """
      timeLeft = timeout
      while True:
        startedSelect = time.time()
        whatReady = select.select([my_socket], [], [], timeLeft)
        howLongInSelect = (time.time() - startedSelect)
        if whatReady[0] == []: # Timeout
          return
        timeReceived = time.time()
        recPacket, addr = my_socket.recvfrom(1024)
        icmpHeader = recPacket[20:28]
        type, code, checksum, packetID, sequence = struct.unpack(
          "bbHHh", icmpHeader
        )
        if packetID == ID:
          bytesInDouble = struct.calcsize("d")
          timeSent = struct.unpack("d", recPacket[28:28 + bytesInDouble])[0]
          return timeReceived - timeSent
        timeLeft = timeLeft - howLongInSelect
        if timeLeft <= 0:
          return
    def send_one_ping(my_socket, dest_addr, ID):
      """
      Send one ping to the given >dest_addr<.
      """
      dest_addr = socket.gethostbyname(dest_addr)
      # Header is type (8), code (8), checksum (16), id (16), sequence (16)
      my_checksum = 0
      # Make a dummy heder with a 0 checksum.
      header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, my_checksum, ID, 1) #压包
      #a1 = struct.unpack("bbHHh",header)  #my test
      bytesInDouble = struct.calcsize("d")
      data = (192 - bytesInDouble) * "Q"
      data = struct.pack("d", time.time()) + data
      # Calculate the checksum on the data and the dummy header.
      my_checksum = checksum(header + data)
      # Now that we have the right checksum, we put that in. It's just easier
      # to make up a new header than to stuff it into the dummy.
      header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, socket.htons(my_checksum), ID, 1)
      packet = header + data
      my_socket.sendto(packet, (dest_addr, 1)) # Don't know about the 1
    def do_one(dest_addr, timeout):
      """
      Returns either the delay (in seconds) or none on timeout.
      """
      icmp = socket.getprotobyname("icmp")
      try:
        my_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
      except socket.error, (errno, msg):
        if errno == 1:
          # Operation not permitted
          msg = msg + (
            " - Note that ICMP messages can only be sent from processes"
            " running as root."
          )
          raise socket.error(msg)
        raise # raise the original error
      my_ID = os.getpid() & 0xFFFF
      send_one_ping(my_socket, dest_addr, my_ID)
      delay = receive_one_ping(my_socket, my_ID, timeout)
      my_socket.close()
      return delay
    def verbose_ping(dest_addr, timeout = 2, count = 100):
      """
      Send >count< ping to >dest_addr< with the given >timeout< and display
      the result.
      """
      for i in xrange(count):
        print "ping %s..." % dest_addr,
        try:
          delay = do_one(dest_addr, timeout)
        except socket.gaierror, e:
          print "failed. (socket error: '%s')" % e[1]
          break
        if delay == None:
          print "failed. (timeout within %ssec.)" % timeout
        else:
          delay = delay * 1000
          print "get ping in %0.4fms" % delay
    if __name__ == '__main__':
      verbose_ping("www.163.com",2,1)

希望本文所述对大家的Python程序设计有所帮助。