我有一个单线程程序，只需通过ssh执行命令，只需通过ssh查找输出。但过了一段时间，我开始变得非常奇怪的行为：
ssh_cmd = 'ssh %s@%s %s' % (user, addr, options)
ssh = pexpect.spawn(ssh_cmd, timeout=60)
lgsuc = ['(?i)(password)')]
for item in loginsuccess:
lgsuc.append(item)
retval = ssh.expect(lgsuc)
for cmd in cmdlist:
time.sleep(0.1)
#this is regex to match anything. Essentially clears the buffer so you don't get an invalid match from before
ssh.expect(['(?s).*'])
ssh.sendline(cmd)
foundind = ssh.expect([re.escape("root#")], 30) #very slow
#repr escape all the wierd stuff so madness doesn't happen with ctr chars
rettxt = repr(ssh.before.decode("us-ascii") + "root:#")
print("We Found:" + rettxt
大约20个命令就可以了，然后发生疯狂假设每次正确的回声都是blablabla：
We found 'blablabla \r\n\r\n[edit]\r\nroot#'
We found 'blablabla \r\n\r\n[edit]\r\nroot#'
We found 'blablabla \r\n\r\n[edit]\r\nroot#'
...大约20个命令......
We found 'bl\r\nroot#' # here it just missed part of the string in the middle
We found 'alala\r\nroot#'
这是前一个命令的其余回声!!!并且当前命令的回声将在一段时间之后出现！它变得越来越糟。奇怪的是它位于返回字节数组的中间。 现在有一些奇怪的控制代码从这个设备返回，所以如果我更换：
rettxt = repr(ssh.before.decode("us-ascii") + "root:#")
带
rettxt = repr(ssh.before.decode("us-ascii") + "root:#")
然后
print("We Found:" + rettxt)
返回：
root#e Found lala
无论如何，pexpect和缓冲区都有一些奇怪的东西，我无法弄清楚它是什么，所以任何帮助都会受到赞赏。我应该提到我永远不会超时，潜水总是响应。此外，日志文件中＆＃34; root：＃＆＃34;的总数超过了发送的总行数。
如果我查看并删除所有ctl代码，输出看起来更干净但问题仍然存在，就好像pextect无法正确处理其缓冲区中的ctl coodes。任何帮助表示赞赏
更新最低可验证示例
好的，我已经能够在孤立的ubuntu环境中重新创建问题的一部分。
首先我需要创建4个可以在主机目标上运行的命令，所以把文件放在〜/我在ubuntu中这样做了 〜/ check.py
#!/usr/bin/python3
import time
import io
#abcd^H^H^H^H^MABC
#mybytes = b'\x61\x62\x63\x64\x08\x08\x08\x0D\x41\x42\x43'
#abcdACB
mybytes = b'\x61\x62\x63\x64\x41\x42\x43'
f = open('test.txt', 'wb')
#time.sleep(1)
f.write(mybytes)
print(mybytes.decode('ascii'))
f.close()
〜/ check2.py
#!/usr/bin/python3
import time
import io
#0123^H^H^H^H^MABC
mybytes = b'\x30\x31\x32\x33\x08\x0D\x0D\x08\x08\x08\x08\x0D\x41\x42\x43'
f = open('test2.txt', 'wb')
#time.sleep(0.1)
f.write(mybytes)
print(mybytes.decode('ascii'))
f.close()
〜/ check3.py
#!/usr/bin/python3
import time
import io
#789:^H^H^H^H^DABC
mybytes = b'\x37\x38\x39\x3A\x08\x08\x08\x08\x08\x08\x08\x0D\x0D\x41\x42\x43'
f = open('test3.txt', 'wb')
#time.sleep(0.1)
f.write(mybytes)
print(mybytes.decode('ascii'))
f.close()
最后check4.py抱歉，这个问题需要一个奇怪的组合才能显示出来
#!/usr/bin/python3
import time
import io
#abcd^H^H^H^HABC
mybytes = b'\x61\x62\x63\x64\x08\x08\x08\x0D\x41\x42\x43'
f = open('test.txt', 'wb')
time.sleep(4)
f.write(mybytes)
print(mybytes.decode('ascii'))
f.close()
注意到最后一个有更大的睡眠，这是遇到texpect超时。虽然在我的实际测试中，这并不是一件好事，但我有超过6分钟的命令可以返回任何文本，因此这可能是其中的一部分。好的，最后的文件运行一切。它可能看起来很丑，但我做了大量修剪，所以我可以在这里发布：
#! /usr/bin/python3
#import paramiko
import time
import sys
import xml.etree.ElementTree as ET
import xml
import os.path
import traceback
import re
import datetime
import pexpect
import os
import os.path
ssh = None
respFile = None
#Error Codes:
DEBUG = True
NO_ERROR=0
EXCEPTION_THROWS=1
RETURN_TEXT_NEVER_FOUND = 2
LOG_CONSOLE = 1
LOG_FILE = 2
LOG_BOTH = 3
def log(out, dummy=None):
print(str(log))
def connect(user, addr, passwd):
global ssh
fout = open('session.log', 'wb')
#options = '-q -oStrictHostKeyChecking=no -oUserKnownHostsFile=/dev/null -oPubkeyAuthentication=no'
options = ' -oUserKnownHostsFile=/dev/null '
#options = ''
#REPLACE WITH YOU LOCAL USER NAME
#user = 'user'
#REPLACE WITH YOUR LOCAL PASSWORD
#passwd = '123TesT321'
#addr = '127.0.0.1'
ssh_cmd = 'ssh %s@%s %s' % (user, addr, options)
public = None
private = None
retval = 0
try:
ssh = pexpect.spawn(ssh_cmd, timeout=60)
ssh.logfile = fout
#the most common prompts
loginsuccess = [re.escape("#"), re.escape("$")]
lgsuc = ['(?i)(password)', re.escape("connecting (yes/no)? ")]
for item in loginsuccess:
lgsuc.append(item)
retval = ssh.expect(lgsuc)
except pexpect.TIMEOUT as exc:
log("Server never connected to SSH tunnel")
return 0
print('where here ret val = ' + str(retval))
try:
if(retval > 1):
return 1
elif(retval == 1):
hostkey = ssh.before.decode("utf-8")
ssh.sendline("yes")
log("Warning! new host key was added to the database: " + hostkey.split("\n")[1])
lgsuc = ['password: ']
for item in loginsuccess:
lgsuc.append(item)
retval = ssh.expect(lgsuc)
if(retval > 0):
return 1
else:
if(public is not None):
log("Warning public key authentication failed trying password if available...")
else:
if public is not None:
log("Warning public key authentication failed trying password if available...")
if(passwd is None):
log("No password and certificate authentication failed...")
return 0
ssh.sendline(passwd)
login = ['password: ' ]
for item in loginsuccess:
login.append(item)
retval = ssh.expect(login)
except pexpect.TIMEOUT as exc:
log("Server Never responded with expected login prompt: "+lgstr)
return 0
#return 0
if retval > 0:
retval = 1
if retval == 0:
log("Failed to connect to IP:"+addr +" User:"+user+" Password:"+passwd)
return retval
def disconnect():
log("Disconnecting...")
global ssh
if ssh is not None:
ssh.close()
else:
log("Something wierd happened with the SSH client while closing the session. Shouldn't really matter", False)
def RunCommand(cmd, waitTXT, timeout = 5):
global ssh
Error = 0
if DEBUG:
print('Debugging: cmd: '+ cmd+'. timeout: '+str(timeout) +'. len of txt tags: '+ str(len(waitTXT)))
if(type(waitTXT) is str):
waitTXT = [re.excape(waitTXT)]
elif(not hasattr(waitTXT ,'__iter__')):
waitTXT = [re.escape(str(waitTXT))]
else:
cnter = 0
for TXT in waitTXT:
waitTXT[cnter] = re.escape(str(TXT))
cnter +=1
#start = time.time()
#print("type3: "+str(type(ssh)))
#time.sleep(1)
#this is regex to match anything. Essentially clears the buffer so you don't get an invalid match from before
ssh.expect(['(?s).*'])
ssh.sendline(cmd)
print("Debugging: sent: "+cmd)
#GoOn = True
rettxt = ""
try:
foundind = ssh.expect(waitTXT, timeout)
allbytes = ssh.before
newbytes = bytearray()
for onebyte in allbytes:
if onebyte > 31:
newbytes.append(onebyte)
allbytes = bytes(newbytes)
rettxt = repr(allbytes.decode("us-ascii") + waitTXT[foundind])
#rettxt = ssh.before + waitTXT[foundind]
if DEBUG:
print("Debugging: We found "+rettxt)
except pexpect.TIMEOUT as exc:
if DEBUG:
txtret = ""
for strtxt in waitTXT:
txtret += strtxt +", "
print("ERROR Debugging: we timed out waiting for text:"+txtret)
pass
return (rettxt, Error)
def CloseAndExit():
disconnect()
global respFile
if respFile is not None and '_io.TextIOWrapper' in str(type(respFile)):
if not respFile.closed:
respFile.close()
def main(argv):
try:
cmds = ['~/check.py', '~/check2.py', '~/check3.py', '~/check2.py', '~/check3.py','~/check.py', '~/check2.py', '~/check3.py', '~/check2.py', '~/check3.py', '~/check4.py', '~/check3.py','~/check.py', '~/check2.py',]
##CHANGE THESE TO MTACH YOUR SSH HOST
ret = connect('user', '127.0.0.1', 'abcd1234')
for cmd in cmds:
cmdtxt = str(cmd)
#rett = RunCommand(ssh, "ls", "root", 0, 5)
strlen = (170 - (len(cmdtxt)))/2
dashval = ''
starval = ''
tcnt = 0
while(tcnt < strlen):
dashval +='-'
starval +='*'
tcnt +=1
if DEBUG:
print(dashval+cmdtxt+dashval)
#checkval = ['ABC']
#REPLACE THE FOLLOWING LINE WITH YOUR TARGET PROMPT
checkval = ['user-virtual-machine:~$']
rett = RunCommand(cmdtxt, checkval, 2)
if DEBUG:
print(starval+cmdtxt+starval)
except Exception as e:
exc_type, exc_obj, exc_tb = sys.exc_info()
fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
print(exc_type, fname, exc_tb.tb_lineno)
print(traceback.format_exc())
CloseAndExit()
#disconnect()
#respFile.close()
main(sys.argv)
确保所有检查和主要python脚本都可以通过sudo chmod 774或类似权限执行。在主函数调用中，将您的用户名ipaddress和密码设置为具有check.py的目标所在的位置，并确保它们位于〜/目录中。
一旦你运行它，你可以看看session.log，至少在脑海中有一些奇怪的东西正在进行缓冲：
~/check4.py^M
~/check3.py
~/check3.py^M
abcd^H^H^H^MABC^M
^[]0;user@user-virtual-machine: ~^Guser@user-virtual-machine:~$ ~/check.py
~/check3.py^M
789:^H^H^H^H^H^H^H^M^MABC^M
^[]0;user@user-virtual-machine: ~^Guser@user-virtual-machine:~$ ~/check.py~/check2.py
不幸的是，它不像我的实际prbolem腐败，但我有几百个命令我是一个嵌入式定制linux内核，我显然无法为每个人重新创建。但无论如何，任何帮助都非常感谢。希望这些例子对你有用，我只是在ubuntu 16.04 lts。还要确保更换用户虚拟机：〜$＆＃39;无论你的目标登录提示是什么样的