Python3+telnetlib Implementing the Telnet Client

I. Key points of the procedure

The six key questions that Python implements for Telnet clients and their answers are:

What libraries are used to implement Telnet client----telnetlib

How to connect the host----Two methods, one is the incoming IP address connection host (TN = telnetlib) when instantiating. Telnet (host_ip,port=23)), and the second is to instantiate the arguments first and then use the Open method to connect to the host (the method I use here)

How to enter the user name password----We use the READ_UNTILB function to listen, after the flag, use the Write method to transfer the user name password to the server

How to execute the command----is still using the Write method to send commands to the server, regardless of the data sent to the server with write; but note the need to encode into a bytes type

How to get command execution results----using the Read_very_eager () method, the method obtains all the input and output before the last fetch, and the bytes type is decode decoded.

How to exit Telnet---Exit Telnet using the Write method to submit the exit command to the server

Second, the program source code

ImportLoggingImportTelnetlibImport Timeclasstelnetclient ():def __init__(self,): self.tn=Telnetlib. Telnet ()#This function implements the Telnet login host    defLogin_host (Self,host_ip,username,password):Try:            #self.tn = Telnetlib. Telnet (host_ip,port=23)Self.tn.open (host_ip,port=23)        except: Logging.warning ('%s Network connection failed'%host_ip)returnFalse#wait for login to enter user name, wait up to 10 secondsSelf.tn.read_until (b'Login:', timeout=10) Self.tn.write (Username.encode ('ASCII') + b'\ n')        #wait for the password to enter the user name, up to 10 secondsSelf.tn.read_until (b'Password:', timeout=10) Self.tn.write (Password.encode ('ASCII') + b'\ n')        #delay two seconds to receive the return result, give the server enough response timeTime.sleep (2)        #Get Login Results        #Read_very_eager () gets all the output from the previous fetch, after the last acquisition.Command_result = Self.tn.read_very_eager (). Decode ('ASCII')        if 'Login Incorrect'  not inchcommand_result:logging.warning ('%s Login succeeded'%host_ip)returnTrueElse: Logging.warning ('%s Login failed with incorrect user name or password'%host_ip)returnFalse#This function implements the command that is passed over and outputs its execution results    defExecute_some_command (self,command):#Execute CommandSelf.tn.write (Command.encode ('ASCII') +b'\ n') Time.sleep (2)        #Get command ResultsCommand_result = Self.tn.read_very_eager (). Decode ('ASCII') logging.warning ('command Execution Result: \n%s'%Command_result)#exit Telnet    defLogout_host (self): Self.tn.write (b"exit\n")if __name__=='__main__': Host_ip='192.168.220.129'username='Root'Password='abcd1234'Command='WhoAmI'telnet_client=telnetclient ()#if the login result returns True, execute the command and then exit    ifTelnet_client.login_host (Host_ip,username,password): Telnet_client.execute_some_command (command) telnet _client.logout_host ()

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Reference:

Https://docs.python.org/3/library/telnetlib.html

Python3+telnetlib Implementing the Telnet Client