We Keep Coding

Telnet Apache Commons NET Printing Junk Characters

We wanted to execute some commands on Windows Server 2008/Windows 7 using telnet. As everytime logining in and running commands on around 50 of the same is tedious so I searched in google and zeored to apache commons and I found an example.
It works but it is printing some junk characters (I'm thinking it is some issue with character encoding of Windows, I'm new to this).
package com.kiran.telnet;
import org.apache.commons.net.telnet.TelnetClient;
import java.io.InputStream;
import java.io.PrintStream;
public class AutomatedTelnetClient {
private TelnetClient telnet = new TelnetClient();
private InputStream in;
private PrintStream out;
private String prompt = ">";
public AutomatedTelnetClient(String server, String user, String password) {
try {
// Connect to the specified server
telnet.connect(server, 23);
// Get input and output stream references
in = telnet.getInputStream();
out = new PrintStream(telnet.getOutputStream(), true);
// Log the user on
readUntil("login: ");
write(user);
readUntil("password: ");
write(password);
// Advance to a prompt
readUntil(prompt + " ");
} catch (Exception e) {
e.printStackTrace();
}
}
public void su(String password) {
try {
write("su");
readUntil("Password: ");
write(password);
prompt = ">";
readUntil(prompt + " ");
} catch (Exception e) {
e.printStackTrace();
}
}
public String readUntil(String pattern) {
try {
char lastChar = pattern.charAt(pattern.length() - 1);
StringBuffer sb = new StringBuffer();
boolean found = false;
char ch = (char) in.read();
while (true) {
System.out.print(ch);
sb.append(ch);
if (ch == lastChar) {
if (sb.toString().endsWith(pattern)) {
return sb.toString();
}
}
ch = (char) in.read();
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public void write(String value) {
try {
out.println(value);
out.flush();
System.out.println(value);
} catch (Exception e) {
e.printStackTrace();
}
}
public String sendCommand(String command) {
try {
write(command);
return readUntil(prompt);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public void disconnect() {
try {
telnet.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
try {
AutomatedTelnetClient telnet = new AutomatedTelnetClient(
"127.0.0.1", "Kiran", "artha");
System.out.println("Got Connection...");
telnet.sendCommand("hostname");
//telnet.sendCommand("ipconfig");
//telnet.sendCommand("ps -ef ");
//System.out.println("run command");
//telnet.sendCommand("ls ");
//System.out.println("run command 2");
telnet.disconnect();
System.out.println("DONE");
} catch (Exception e) {
e.printStackTrace();
}
}
}
The Output while I run this is:
Welcome to Microsoft Telnet Service
login: Kiran
Kiran
password: artha
[1;1H*=============================================================== [2;1HMicrosoft Telnet Server. [3;1H*=============================================================== [4;1HC:\Users\Kiran> Got Connection...
hostname
[5;1H[K[6;1H[K[7;1H[K[8;1H[K[9;1H[K[10;1H[K[11;1H[K[12;1H[K[13;1H[K[14;1H[K[15;1H[K[16;1H[K[17;1H[K[18;1H[K[19;1H[K[20;1H[K[21;1H[K[22;1H[K[23;1H[K[24;1H[K[25;1H[K[4;16Hhostname[5;1HKiran-PC[7;1HC:\Users\Kiran>DONE
And some ESC char before "["
Any help regarding this one.
Thank You.

Take a look at this wiki article. This symbols are just control characters, used to format the output in your terminal.
You can try to configure your terminal type like:
TelnetClient telnet = new TelnetClient("dumb");
Or you can try to configure it with TerminalTypeOptionHandler.
By default your telnet client is created with terminal type vt100' which supports control sequences. The dumb one does not support them. But you have to understand, that it is not guaranteed, that remote server support this terminal type.

execute shell command from android

I'm trying to execute this command from the application emulator terminal (you can find it in google play) in this app i write su and press enter, so write:
screenrecord --time-limit 10 /sdcard/MyVideo.mp4
and press again enter and start the recording of the screen using the new function of android kitkat.
so, i try to execute the same code from java using this:
Process su = Runtime.getRuntime().exec("su");
Process execute = Runtime.getRuntime().exec("screenrecord --time-limit 10 /sdcard/MyVideo.mp4");
But don't work because the file is not created. obviously i'm running on a rooted device with android kitkat installed. where is the problem? how can i solve? because from terminal emulator works and in Java not?

You should grab the standard input of the su process just launched and write down the command there, otherwise you are running the commands with the current UID.
Try something like this:
try{
Process su = Runtime.getRuntime().exec("su");
DataOutputStream outputStream = new DataOutputStream(su.getOutputStream());
outputStream.writeBytes("screenrecord --time-limit 10 /sdcard/MyVideo.mp4\n");
outputStream.flush();
outputStream.writeBytes("exit\n");
outputStream.flush();
su.waitFor();
}catch(IOException e){
throw new Exception(e);
}catch(InterruptedException e){
throw new Exception(e);
}

A modification of the code by #CarloCannas:
public static void sudo(String...strings) {
try{
Process su = Runtime.getRuntime().exec("su");
DataOutputStream outputStream = new DataOutputStream(su.getOutputStream());
for (String s : strings) {
outputStream.writeBytes(s+"\n");
outputStream.flush();
}
outputStream.writeBytes("exit\n");
outputStream.flush();
try {
su.waitFor();
} catch (InterruptedException e) {
e.printStackTrace();
}
outputStream.close();
}catch(IOException e){
e.printStackTrace();
}
}
(You are welcome to find a better place for outputStream.close())
Usage example:
private static void suMkdirs(String path) {
if (!new File(path).isDirectory()) {
sudo("mkdir -p "+path);
}
}
Update:
To get the result (the output to stdout), use:
public static String sudoForResult(String...strings) {
String res = "";
DataOutputStream outputStream = null;
InputStream response = null;
try{
Process su = Runtime.getRuntime().exec("su");
outputStream = new DataOutputStream(su.getOutputStream());
response = su.getInputStream();
for (String s : strings) {
outputStream.writeBytes(s+"\n");
outputStream.flush();
}
outputStream.writeBytes("exit\n");
outputStream.flush();
try {
su.waitFor();
} catch (InterruptedException e) {
e.printStackTrace();
}
res = readFully(response);
} catch (IOException e){
e.printStackTrace();
} finally {
Closer.closeSilently(outputStream, response);
}
return res;
}
public static String readFully(InputStream is) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int length = 0;
while ((length = is.read(buffer)) != -1) {
baos.write(buffer, 0, length);
}
return baos.toString("UTF-8");
}
The utility to silently close a number of Closeables (Soсket may be no Closeable) is:
public class Closer {
// closeAll()
public static void closeSilently(Object... xs) {
// Note: on Android API levels prior to 19 Socket does not implement Closeable
for (Object x : xs) {
if (x != null) {
try {
Log.d("closing: "+x);
if (x instanceof Closeable) {
((Closeable)x).close();
} else if (x instanceof Socket) {
((Socket)x).close();
} else if (x instanceof DatagramSocket) {
((DatagramSocket)x).close();
} else {
Log.d("cannot close: "+x);
throw new RuntimeException("cannot close "+x);
}
} catch (Throwable e) {
Log.x(e);
}
}
}
}
}

Process p;
StringBuffer output = new StringBuffer();
try {
p = Runtime.getRuntime().exec(params[0]);
BufferedReader reader = new BufferedReader(
new InputStreamReader(p.getInputStream()));
String line = "";
while ((line = reader.readLine()) != null) {
output.append(line + "\n");
p.waitFor();
}
}
catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
String response = output.toString();
return response;

Late reply, but it will benefit someone. You can use the sh command in the exec() method.
Here is my example:
try {
File workingDirectory = new File(getApplicationContext().getFilesDir().getPath());
Process shProcess = Runtime.getRuntime().exec("sh", null, workingDirectory);
try{
PrintWriter outputExec = new PrintWriter(new OutputStreamWriter(shProcess.getOutputStream()));
outputExec.println("PATH=$PATH:/data/data/com.bokili.server.nginx/files;export LD_LIBRARY_PATH=/data/data/com.bokili.server.nginx/files;nginx;exit;");
outputExec.flush();
} catch(Exception ignored){ }
shProcess.waitFor();
} catch (IOException ignored) {
} catch (InterruptedException e) {
try{ Thread.currentThread().interrupt(); }catch(Exception ignored){}
} catch (Exception ignored) { }
What have I done with this?
First I call the shell, then I change (set) the necessary environments in it, and finally I start my nginx with it.
This works on unrooted devices too.
Greetings.

Echo the content of a TextView?

I have a class with this code
public boolean busybox() throws IOException
{
try
{
Process p =Runtime.getRuntime().exec("busybox");
InputStream a = p.getInputStream();
InputStreamReader read = new InputStreamReader(a);
BufferedReader in = new BufferedReader(read);
StringBuilder buffer = new StringBuilder();
String line = null;
try {
while ((line = in.readLine()) != null) {
buffer.append(line);
}
} finally {
read.close();
in.close();
}
String result = buffer.toString().substring(0, 15);
System.out.println(result);
return true;
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
In another class I have this code
try {
if(root.busybox()) {
Busybox.setText(Html.fromHtml((getString(R.string.busybox))));
}
else {
Busybox.setText(Html.fromHtml((getString(R.string.no))));
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
If I want to write in this TextView the outpout generated by System.out.println(result);
How can i do? Thanks in advance! I made several attempts, but I have several errors and the code is wrong.

change return type of public boolean busybox() to string like public String busybox() and return result.
then use
try {
String myResult=root.busybox();
if(myResult!=null&&myResult.length>0) {
Busybox.setText(Html.fromHtml((myResult)));
}
else {
Busybox.setText(Html.fromHtml((getString(R.string.no))));
}
}

Java Socket: NTP application always return null string

I have use some code to take time from NTP (Network Time Protocol). I have tried many servers from this list but always receive an empty string. I don't know this is because server error, or my code has some problem.
Here is my code:
String machine = "utcnist2.colorado.edu";
// standart port on Computer to take time of day on normal computer
final int daytimeport = 13;
Socket socket = null;
try {
socket = new Socket(machine, daytimeport);
BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String time = reader.readLine();
System.out.printf("%s says it is %s %n", machine, time);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}

Aparently, the server returns two lines. Adding reader.readLine(); just before String time = reader.readLine(); makes it work.
Full code would be:
public static void main(String[] args) {
String machine = "utcnist2.colorado.edu";
// standart port on Computer to take time of day on normal computer
final int daytimeport = 13;
Socket socket = null;
try {
socket = new Socket(machine, daytimeport);
BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
reader.readLine();
String time = reader.readLine();
System.out.printf("%s says it is %s %n", machine, time);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

Java - passing input into external C/C++ application

I'm trying to enter some value in external application using Java.
Java application looks like this:
Runtime runtime = Runtime.getRuntime();
// ... str build ...
proc = runtime.exec(str);
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(proc.getOutputStream()));
bw.write(value);
bw.flush();
bw.close();
if (proc.waitFor() != 0)
// error msg
// the end
Application hangs at waitFor method.
External application looks like this:
welcome banner
please enter 8 character input:
Welcome banner is printed using printf and input is taken with SetConsoleMode/ReadConsoleInput. ReadConsoleInput reads one char and they are masked with * character.
Help

you can use:
proc.getOutputStream().write("some date".getBytes())
keep in mind that you HAVE to read everything the app send to stdout and stderr, else it might get stuck writing there.
I use a generic class to read it in a different thread.
usage is like:
InputStreamSucker inSucker = new InputStreamSucker(proc.getInputStream());
InputStreamSucker errSucker = new InputStreamSucker(proc.getErrorStream());
proc.waitFor();
int exit = process.exitValue();
inSucker.join();
errSucker.join();
InputStreamSucker code is here:
public class InputStreamSucker extends Thread
{
static Logger logger = Logger.getLogger(InputStreamSucker.class);
private final BufferedInputStream m_in;
private final ByteArrayOutputStream m_out;
private final File m_outFile;
public InputStreamSucker(InputStream in) throws FileNotFoundException
{
this(in, null);
}
public InputStreamSucker(InputStream in, File outFile) throws FileNotFoundException
{
m_in = new BufferedInputStream(in, 4096);
m_outFile = outFile;
m_out = new ByteArrayOutputStream();
start();
}
#Override
public void run()
{
try
{
int c;
while ((c = m_in.read()) != -1)
{
m_out.write(c);
}
}
catch (IOException e)
{
logger.error("Error pumping stream", e);
}
finally
{
if (m_in != null)
{
try
{
m_in.close();
}
catch (IOException e)
{
}
}
try
{
m_out.close();
}
catch (IOException e)
{
logger.error("Error closing out stream", e);
}
if (m_outFile != null)
{
byte data[] = m_out.toByteArray();
if (data.length > 0)
{
FileOutputStream fo = null;
try
{
fo = new FileOutputStream(m_outFile);
fo.write(data);
}
catch (IOException e)
{
logger.error("Error writing " + m_outFile);
}
finally
{
try
{
if (fo != null) fo.close();
}
catch (IOException e)
{
logger.error("Error closing " + m_outFile);
}
}
}
}
}
}
public String getOutput()
{
return new String(m_out.toByteArray());
}
}

Got the answer! The trick is to use WriteConsoleInput() API because program expects keyboard event, not text ... That's why the waitFor() waited forever! :)