我發現下面的代碼在網上時,添加創建的列表,打印長度的嘗試「ValueError異常:在關閉的文件I/O操作」試圖打印列表
from __future__ import print_function
import socket
import struct
import sys
import os
import webbrowser
import json
import urllib
# We want unbuffered stdout so we can provide live feedback for
# each TTL. You could also use the "-u" flag to Python.
class flushfile(file):
def __init__(self, f):
self.f = f
def write(self, x):
self.f.write(x)
self.f.flush()
sys.stdout = flushfile(sys.stdout)
def main(dest_name):
dest_addr = socket.gethostbyname(dest_name)
port = 33434
max_hops = 30
icmp = socket.getprotobyname('icmp')
udp = socket.getprotobyname('udp')
ttl = 1
IPlist = []
while True:
recv_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
send_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, udp)
send_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl)
# Build the GNU timeval struct (seconds, microseconds)
timeout = struct.pack("ll", 5, 0)
# Set the receive timeout so we behave more like regular traceroute
recv_socket.setsockopt(socket.SOL_SOCKET, socket.SO_RCVTIMEO, timeout)
recv_socket.bind(("", port))
sys.stdout.write(" %d " % ttl)
send_socket.sendto("", (dest_name, port))
curr_addr = None
curr_name = None
finished = False
tries = 1
while not finished and tries > 0:
try:
_, curr_addr = recv_socket.recvfrom(512)
finished = True
curr_addr = curr_addr[0]
except socket.error as (errno, errmsg):
tries = tries - 1
sys.stdout.write("* ")
send_socket.close()
recv_socket.close()
if not finished:
pass
if curr_addr is not None:
IPlist.append(curr_addr)
print(len(IPlist))
ttl += 1
if curr_addr == dest_addr or ttl > max_hops:
break
if __name__ == "__main__":
main('google.com')
這是示例代碼模擬traceroute
的功能。
我試圖添加(通過使用append
)所有存儲在curr_addr
中的IP地址列表。我正在檢查該行列表的長度以確保它不斷增長。
我每次運行它,我得到這個錯誤:
1 Traceback (most recent call last):
File "traceroute.py", line 96, in <module>
main('google.com')
File "traceroute.py", line 84, in main
print(len(IPlist))
ValueError: I/O operation on closed file
不要忽略上面的行號,因爲我已刪除了之前發佈的註釋代碼了。
你爲什麼每次迭代循環都要打開/關閉套接字? –
@JonathonReinhart部分代碼不是我的。我完全不理解它,並且正在慢慢嘗試。我唯一的代碼是列表並試圖獲取它的長度。也許我應該說,在主帖 –
爲什麼你搞亂'sys.stdout'和'flushfile'的東西,而不是隻是添加'flush = True'到相關的print()調用? – TigerhawkT3