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Telnet will happily print whatever you send from your server, so you should already see something. Public static void main(String args) throws IOException ? Also, if my program weren't in localhost, how would I know what IP to telnet to? Therefore, what I guess you want is something like this: ssh is just the same, although it adds ssl/tls security to the channel. You can browse the web by using the command telnet 80 and manually enter all the http protocol stuff, but i wouldn't recommend it. Telnet in particular can be (and has been) abused to send general text-commands over a tcp connection. Since both telnet and ssh requires some application to run on the remote machine (most often an instance of a command shell), they really only provide the transport mechanism for the commands. What exactly do you mean by "telnet into my app where by they can type in commands etc."? Java - telnet through SSH - Stack Overflow java ssh telnet
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This might well cause all the problems you're having. \n in java), as the telnet server expects a user to press the enter key. java program can not make stream read-write properly during telnet you shouldn't send an EOF but a CR or CR/LF (a.k.a. It can also work locally but the problem is not SSH layer.Also problem is not about communication. or does the telnet also not work locally? It asks for username then i'm writing it to stream (with EOF) but hangs there foreverīut if the telnet server is local the java program can communicate with it, right? i.e. Need a java solution :( I tried that way in java but can not login telnet. Then you can open a telnet connection on the original host to 2323 which gets forwarded to the remote host port 23 via ssh. In putty you can configure the tunnel in connection/ssh/tunnels, there you can enter a remote port (for example 23) and a local unused port (lets say 2323). Not sure if/how you could do that in Java though. It will be almost same,except we will have a ArrayList/Array of commands in hand before we create Socket.And then change the loop onto the list to execute all the commands one after another.You could try to tunnel telnet over SSH, then you could open the telnet session on the original host running the java program. This gives you same telnet as you got in your OS, so i think its simple but good to know :) If(c!='\0')while(!Command.equals("quit")) //exit the loop if user sends 'quit'. PrintWriter dout = new PrintWriter(soc.getOutputStream(),true) īufferedReader br=new BufferedReader(new InputStreamReader(System.in)) See,we have taken InputStream of socket and made a PrintWriter on the OutputStreamof it to send commands.Also we have taken BufferedReader for user inputs from CL. There are two ways to make a telnet client using Sockets.ġ.Make it CLI based,means which accepts every input from Command Line Interface entered by user.Ģ.Make it automated,which takes command list from some file or database,generates a script or list of commands and run it whole on host.įirst one is quite easy,i think you all might have done that :).Just let me tell you little what to do.ĭataInputStream din=new DataInputStream(soc.getInputStream()) So, we have another,'Socket' way here, which connects to perticular host on given port number and try to open TCP connection with it.If the host is listening on port and connection accepted,then we can send our commands to the host.(I know, i know, that we all know sockets since our starting graduation days :) ,but let me tell guys. In first way, we need to get hands on the process.We can achieve that using Process p = Runtime.getRuntime().exec()But i don't think this should be used for telnet like communication,because telnet requires continuous session running on remote server and executing you commands.Sometimes it can be so that after executing several commands,you need to rollback so you can cancle all the commands.so its a continuous and sequential process most of the times.The Process class used can be out of our hands anytime if the executable crashes or if anything bad happen(Mostly.the exe crash.). Use windows/linux telnet command line utility (which is same on both win and linux. Through java, if we want to make remote connection over some port then we have two different ways.ġ. Telnet is very important utiliy we use.We can call remote server commands and use different services running on perticular port.Mostly telnet server runs on 23,but can be differed.