[java.lang.Process] Howto simulate ENTER ?

Hi there!
I need to control an interactive command-line tool from java (smbclient) and for this task I use Process with getOutputStream().
However I want to send commands to the native-program like: Process.getOutputStream.write("exit\n".getBytes()) but it simply does not work :-(
I think the native programs does not recognize the "\n" as <ENTER> .
Any ideas howto solve this problem?
Thanks you in advance, Clemens Eisserer

Well, thanks for the tips!
Since I am running Unix '\n' shoulb we enough, but thanks for remembering me g
Well, I actually forgot to flush the output-Stream. Nobody is perfect ;-)
Thanks again, lg Clemens

Similar Messages

Java.lang.Process output stream problem

Hi, I have a program that starts a process (java.lang.Process) using the java.lang.Runtime.exec() and it attemtps to interface with it using the provieded io streams. I have both the output and error streams being handled on their own threads and I have a hashmap of output lines/command pairs that are checked so that when the process outputs certain lines to the console it feed the proper input into the process. My problem is that when I feed the input into the process it dosen't respond to it almost like the user hasn't pressed enter, The process hangs. I have tried using /n /r and permutations thereof but nothing works. The thread does read the lines from the process and does output to the process from what i can gather. Can you help me!
here is some of the code..
public void run() {
try {
     //the process's output
     InputStreamReader isrOutput = new InputStreamReader(inOutput);
     //the process's input(our output)
     PrintWriter pw = new PrintWriter(outInput);
     String line = null;
     while(true){
          if(brOutput.ready()){
               line = "";
               while(brOutput.ready())
     line+=(char)brOutput.read();
               System.out.print(line);
               if(commands.containsKey(line)){
     pw.println((String)commands.get(line));
     System.out.println((String)commands.get(line));;
} catch (IOException ioe) {
          ioe.printStackTrace();
}Thanks

Oops.. i forgot to flush my PrintWriter /blushing......... Thanks

Java.lang.process.execute()

Java.lang.process.execute() is throwing an exception with string �Cannot allocate memory� ...
what is the cause of this exception and give me the solution
plz help
Nilesh

882590 wrote:
Is it possible to use the java.lang.ProcessBuilder to execute a Java process pointing it to jvm.dll instead of java.exe? I'm using the JavaFX self contained application packaging and it creates a runtime/jre/bin directory that contains jvm.dll, but not java.exe.I don't get the line of questioning of this thread. If you're using the JavaFX stuff the answer must lie in the JavaFX documentation. It seems to indicate that it generates an executable of its own which will likely wrap the jvm DLL, so you should be invoking the generated executable in ProcessBuilder.
http://docs.oracle.com/javafx/2/deployment/self-contained-packaging.htm

Java.lang.Process.exec()

I have read a article about the "java.lang.Process.exec()" (url:http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html)
Having some questions with the example in it.
The example code:
import java.util.*;
import java.io.*;
public class BadExecJavac
    public static void main(String args[])
        try
            Runtime rt = Runtime.getRuntime();
            Process proc = rt.exec("javac");
            //int exitVal = proc.exitValue();
            int exitVal = proc.waitFor();
            System.out.println("Process exitValue: " + exitVal);
        } catch (Throwable t)
            t.printStackTrace();
}The process can run but never complete.
Why? Just because when invoke the javac.exe without any argument,it will product a set of usage statements that describe how to run the program and the meaning of all the available program options.So the process is in deadlock.
The question is, when i change the exec("javac") to exec("javac a.java"), in which the "a.java" is not exist, so the jvm should product error:
error: cannot read: a.java
1 error
But after i changed the code and run the class, at this time the process can run and complete.
The two codes both product some statements,but why the first one never complete,but the second did. Why?

import java.util.*;
import java.io.*;
public class A
    public static void main(String args[])
        try
            Runtime rt = Runtime.getRuntime();
            Process proc = rt.exec("javac");
            InputStream is = proc.getErrorStream();
            int i=0;
            while ((i = is.read()) != -1)
                System.out.print((char)i);
            // int exitVal = proc.exitValue();
            // int exitVal = proc.waitFor();
            // System.out.println("Process exitValue: " + exitVal);
        } catch (Throwable t)
            t.printStackTrace();
}usng this modification, i could see some error messages.
because exec(cmd) executes the command in a separate process, it will not display the results on the current console. If you want see the results, you should use getInputStream() and getErrorStream().
good luch ^^

Java.lang.Process input stream waiting until process is complete to print

I have tried to simplify this problem as much as possible. Basically, I have a java.lang.Process which executes a simple C program.
test.c
#include <stdio.h>
#include <unistd.h>
int main()
printf("foo\n");
sleep(2);
printf("bar\n");
...The process has an input stream and error stream handler each on a separate thread. I have tried both buffered and unbuffered (BufferedReader, BufferedInputStream, InputStreamReader...) stream handlers. Both produce the same problem of waiting until the process has exited to receive anything from the process's streams.
The only time this does not happen is when I call fflush(stdout); after each printf(). This can't be a solution because the real application calls a massive C application which would require thousands of fflush()'s to be added. What is causing this to happen? This doesn't happen when the C program is executed from the shell. Is there a way the InputStream can be forced to extract from the stream?

hi.....
I have closed the output stream of the process as you told me to do...
The hitch is that, if my program contains only printf() statements,it works fine
as soon as scanf() statement is encountered within the C code,it is totally neglected,and the output comes as if no scanf() statement existed in the C code.
Consequently the thread doesnt wait for input which was bound for scanf() from the thread
the code...
    public void run()
     try
         PrintWriter out = new PrintWriter(socket.getOutputStream(),true);
         BufferedReader in = new BufferedReader(
                        new InputStreamReader(
                        socket.getInputStream()));
         try
                 Process p;
          p=new ProcessBuilder("./a.out").start();
                 PrintWriter exOut=null;
                 BufferedReader exIn=null;
          exOut = new PrintWriter(p.getOutputStream(),true);
          exIn = new BufferedReader(
                       new InputStreamReader(
                       p.getInputStream()));
              //String inputLine="", outputLine="";
              String str="";
                 int c;
              while(true)
                    //System.out.println("In While");
              str="";exOut.close();
                    while((c=exIn.read())!=-1)
                             str=str+(char)(c);
                                System.out.print(str);
                    str=str+(char)(0);
                    System.out.print(str+"outside");
                    out.print(str);
                    sleep(100);
                    try
                        int x=p.exitValue();
                          out.print(str);
               System.out.print("Bye 1");
                        String str1="Bye"+(char)(0);
               out.println(str1);
               break;
                    catch(IllegalThreadStateException e)
                        //System.out.println("The Process has not ended yet");
                    //str=str+((char)-1);
                    //System.out.print(str+"Control reaches here too");
                    str="";
                    exOut = new PrintWriter(p.getOutputStream(),true);//I have tried to run the program without this also but the effect is the same
                    while((c=in.read())!=-1)
                        str=str+(char)(c);
                    if(str.contentEquals(""))
                            System.out.print("Bye 2");
                            String str1="Bye"+(char)(0);
                            out.println(str1);
                            p.destroy();
                            exOut.close();
                            exIn.close();
                            out.close();
                            in.close();
                            socket.close();
                            break;
                    //str=str+(char)(0);
              exOut.print(str);
                    try
                        int x=p.exitValue();
                        System.out.print("Bye 3");
                        String str1="Bye"+(char)(0);
               out.println(str1);
                        break;
                    catch(IllegalThreadStateException e)
                        //System.out.println("The Process has not ended yet");
              /*while ((inputLine = in.readLine()) != null)
                    exOut.println(inputLine);
                    outputLine=exIn.readLine();
                    //outputLine=inputLine;
                    //out.println(outputLine);}*/
         exOut.close();
         exIn.close();
         catch(IOException e)
              System.err.println("Accept failed."+e);
         out.close();
         in.close();
         socket.close();
     catch (Exception e)
         e.printStackTrace();
}

Problem with starting a sqlplus-process via java.lang.Process

Hi,
I want to start a sqlplus-Process from a java-application via java.lang.Process. Works great with XP. On a W2K-Machine, the process is started (I can see it in the Taskmanager), but it doesn't connect to the db - the OS-process hangs, also the java-application which invoked the process.
If I start a sqlplusw.exe-Process instead of sqlplus.exe, it works as well.
Does anybody know what's going wrong ?
I'm using java 1.5.0_11 and Oracle Database 10g Enterprise Edition Release 10.2.0.3.0
Thanks in advance
Jens

java.lang.Process can be used to perform an OS Shell to launch specific tasks. But why are you interested in specifically launching sqlplus from here?
~ Madrid
http://hrivera99.blogspot.com/

Problwm with java.lang.Process

I am using java.lang.Process to read the output of a command, it works fine with one word commands such as "ls", but a command with a pipe and and arguments returns no output, for example "who | grep root".
Any ideas!

for example "who | grep root".
Any ideas! Probably because you really should have nothing returned. Try to give the output of the first command as an input to the second one but not through a pipe; use java.lang.Process twice.

Get complete output from java.lang.Process

How do I get the complete output from java.lang.Process?
By the time I've started reading from Process.getInputStream() the process has already terminated...

I solved the problem:
private int exec(String pArguments[], OutputStream pOut, OutputStream pErr) throws IOException {
     class ProcessOutputPrinter implements Runnable {
          private InputStream ivIn;
          private OutputStream ivOut;
          public ProcessOutputPrinter(InputStream pIn, OutputStream pOut) {
               ivIn = pIn;
               ivOut = pOut;
          public void run() {
               try {
                    for(int tByte; (tByte = ivIn.read()) != -1; ) {
                         ivOut.write(tByte);
                    ivOut.flush();
               catch(IOException e) {
                    e.printStackTrace();
     // Start process
     Process tProcess = Runtime.getRuntime().exec(pArguments);
     // Create out printer
     Thread tOutPrinter = new Thread(new ProcessOutputPrinter(tProcess.getInputStream(), pOut), "NamingAdmin out-printer");
     tOutPrinter.start();
     // Create err printer
     Thread tErrPrinter = new Thread(new ProcessOutputPrinter(tProcess.getErrorStream(), pErr), "NamingAdmin err-printer");
     tErrPrinter.start();
     // Wait for process and printers to finish
     try {
          tProcess.waitFor();
          tOutPrinter.join();
          tErrPrinter.join();
     catch(InterruptedException e) {
     // return process exit value
     return tProcess.exitValue();

Java.lang - process builder

I want to execute the following command inside my java program
rep_cmd [file1] -text [file2]
The above command belongs to an application installed on my PC.
The above command when executed in the command prompt works fine.
but it does not work inside my java program
here is my code:
public class ProcBuild
public static void main(String args[]) throws IOException, InterruptedException
String cmdLine="cmd /c rep_cmd log.wgl -text log1.txt";
ProcessBuilder pr=new ProcessBuilder(cmdLine);
pr.start();
and here is my error message with output:
run:
Exception in thread "main" java.io.IOException: Cannot run program "cmd /c "rep_cmd log.wgl" -text "log1.txt"": CreateProcess error=2, The system cannot find the file specified
     at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
     at ProcBuild.main(ProcBuild.java:23)
Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified
     at java.lang.ProcessImpl.create(Native Method)
     at java.lang.ProcessImpl.<init>(ProcessImpl.java:188)
     at java.lang.ProcessImpl.start(ProcessImpl.java:132)
     at java.lang.ProcessBuilder.start(ProcessBuilder.java:1021)
     ... 1 more
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)
Edited by: user13286843 on Jan 20, 2012 9:20 AM

>
Exception in thread "main" java.io.IOException: Cannot run program "cmd /c "rep_cmd log.wgl" -text "log1.txt"":
>
You are passing the entire command as one String and the string is being interpreted as the name of the program and no arguments.
See the Javadocs for ProcessBuilder. It has an example that shows how to pass the cmd, and each argument as separate Strings.
Get the Javadoc example working first and then substitute your command and arguments.
Starting a new process which uses the default working directory and environment is easy:
Process p = new ProcessBuilder("myCommand", "myArg").start();
Here is an example that starts a process with a modified working directory and environment:
ProcessBuilder pb = new ProcessBuilder("myCommand", "myArg1", "myArg2");
Map<String, String> env = pb.environment();
env.put("VAR1", "myValue");
env.remove("OTHERVAR");
env.put("VAR2", env.get("VAR1") + "suffix");
pb.directory(new File("myDir"));
Process p = pb.start();

About java.lang.Process class?

hi, i am executing one batch file (it contains 2 executable statements) through java.lang.Runtime class exec method like this..Process p1=r.exec("cmd /K start .\\Skeletons\\reports\\FormatFiles\\"+strDTab+".bat");.. i want to get the output of this process is it success, failure or suspect?. how to use the waitFor() method of Process class in this situation?. and also the execution of the batch program will give some status (if fail it will throw some exception), i want to catch the status. depending on the status i will decide proceed to further statements or not?..

You use waitFor() by calling it on the process you get back from the exec()
If you want examples use google to find them.

Linux, java.lang.Process.getOutputStream() funniness

Hi,
I'm using RedHat 7.1, and Sun JDK 1.3.0_02 (on Intel).
From my Java app, I'm trying to launch another process, and redirect my
console in/out to the slave process's in/out.
After launching the process (using Runtime.exec), I launch three
background threads:
1. Monitor the slave process's getInputStream and write all incoming
bytes to my System.out
2. Monitor the slave process's getErrorStream and write all incoming
bytes to my System.out
3. Monitor my System.in and write all incoming bytes to the slave
process's getOutputStream
The funniness I'm experiencing is in step 3 -- it seems that I have to
press each keystroke TWICE, for it to register into the slave process.
For example, as a test, I am launching "lynx http://www.cnn.com", and
the lynx options "H" and "O" I have to press twice (H-H or O-O) to get
the appropriate screen to pop up. In fact, the first keystroke I enter
doesn't matter; it's as if every other keystroke is looked at.
Here is my code for thread #3:
// -------- Begin code fragment
// Start an input thread
Thread inThread = new Thread() {
   public void run() {
      OutputStream out = slaveProcess.getOutputStream();
      byte[] buffer = new byte[1024];
      int len;
      while (true) {
         try {
            len = System.in.read(buffer);
            if (len == -1) break;
            //System.out.println("Bytes read from keyboard: " + len);
            out.write(buffer, 0, len);
            out.flush();
         } catch (Exception e) {
            break;
      System.out.println("inThread exiting");
inThread.start();
// -------- end code fragment In reference to some older JVM bugs, I've tried inserting
Thread.currentThread().sleep(1) at various points (in case there is a
scheduler problem), but to no avail.
Any help would be appreciated!
Thank you,
Bryan

I would test it buy using three FileIn/OutputStreams
instead of Syatem.in/out/err and if it worked at that
point it would be the synchronization/blocking problem.
Because I have used Process.getInputStream on linux on
several occasions and never anything like you are
talking about happened.

Java.lang.Process - detecting process termination asynchronously

Hi All,
I was wondering if there is anyway to know when a Process (run with Runtime.exec()) has terminated without dedicating a thread per Process and using waitFor().
The reason I want this is that I have an application running many such processes concurrently, and I wouldn't want to dedicate a thread for each process to detect its termination.
What I would REALLY like is something like the asynchronous IO 'select' method so that a single thread can block until one of a set of processes terminates.
Polling would not be as good, but also a viable alternative. However, the only way I could see is calling exitValue() periodically on all Process objects - this would mean getting IllegalThreadStateExceptions thrown galore, as long as the process doesn't terminate. This is both ugly and inefficient (makes the penalty for polling even worse - we generate an exception for each non-terminated process polled...).
Does anyone have any tips I can use to implement some sort of solution?
Thanks,
Ophir.

>
What's the requirement for detecting the completed
processes? I'm not really sure why the Thread per
process version wasn't acceptable. How many processes
are there?
Well... it's an application server, and I'm providing a generic capability. Theoretically, it could be hundreds of processes.
Also, did you make sure that the Process Object is
indeed not collectable until the process is complete?I have to say I was pretty skeptical about this myself... ;)
I have made the test as well as I know: I ran a long running process, and then terminated it with 'kill'.
I also ran 'sleep 60' to see what happens on normal termination.
I saw nothing added to the queue while the process was up, and immediate enqueuing after process termination.
I guess there's no way of making ABSOLUTELY sure this works but if it didn't become collectable 20 consecutive times when up, and became collectable immediately when terminated, that's pretty strong circumstancial evidence...
Still I just wish there was a neater, tighter solution (though, using your hack, I'm going to get a lot of admiration from some of the people around here - they don't need to know where I got it...).

Configure Process Flow :Java.lang.Exception:Invalid Connection(0)

I want to install the process flow . I started the wfinstall.bat from below folder
<OWB_HOME>\dbhome_1\owb\wf\install .
It display me Workflow 2.6.4.0.0 and i entered the details
Install option:-Server Only
Workflow Account:-wks_owf_mgr
Workflow Password:- wks_owf_mgr
Syst password :- orcl11g
(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = Devowb-PC)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl11g) ) )
It give me error :- Java.lang.Exception:Invalid Connection(0)
But i am able to connect to sqlplus using
sqlplus "sys/orcl11g@(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = Devowb-PC)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl11g) ) )" as sysdba
Thanks

but i see strange problem i can connect even if i give wrong password.
Donot know why...
sqlplus "sys/orcl11g@(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = Devowb-PC)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl11g) ) )" as sysdba

Java.lang.Exception: ORA-00020: maximum number of processes (150) exceeded?

When i run my web-application with the embedded OC4J server, the following error message is prompted:
java.lang.Exception: ORA-00020: maximum number of processes (150) exceeded
     void MyFolder.objects.MyObject.<init>(oracle.jbo.ApplicationModule, java.lang.String, java.lang.String, javax.servlet.http.HttpServletRequest)
     void MyFolder.servlet.MyServlet.doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     void javax.servlet.http.HttpServlet.service(com.evermind.server.http.EvermindHttpServletRequest, com.evermind.server.http.EvermindHttpServletResponse)
     void javax.servlet.http.HttpServlet.service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     void javax.servlet.http.HttpServlet.service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
     void com.evermind.server.http.ServletRequestDispatcher.invoke(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
     void com.evermind.server.http.ServletRequestDispatcher.forwardInternal(javax.servlet.ServletRequest, javax.servlet.http.HttpServletResponse)
     boolean com.evermind.server.http.HttpRequestHandler.processRequest(com.evermind.server.ApplicationServerThread, com.evermind.server.http.EvermindHttpServletRequest, com.evermind.server.http.EvermindHttpServletResponse, java.io.InputStream, java.io.OutputStream, boolean)
     void com.evermind.server.http.HttpRequestHandler.run(java.lang.Thread)
     void com.evermind.util.ThreadPoolThread.run()
Question:
- What is the cause of this error message? How to avoid?
- I intended to deploy my application to 9IAS server. Will the same problem occurs too?
Thanks for your reply!

Hi Pig,
When i run my web-application with the embedded OC4J server, the following error message is prompted:
java.lang.Exception: ORA-00020: maximum number of processes (150) exceeded
     void MyFolder.objects.MyObject.<init>(oracle.jbo.ApplicationModule, java.lang.String, java.lang.String, javax.servlet.http.HttpServletRequest)
     void MyFolder.servlet.MyServlet.doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     void javax.servlet.http.HttpServlet.service(com.evermind.server.http.EvermindHttpServletRequest, com.evermind.server.http.EvermindHttpServletResponse)
     void javax.servlet.http.HttpServlet.service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     void javax.servlet.http.HttpServlet.service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
     void com.evermind.server.http.ServletRequestDispatcher.invoke(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
     void com.evermind.server.http.ServletRequestDispatcher.forwardInternal(javax.servlet.ServletRequest, javax.servlet.http.HttpServletResponse)
     boolean com.evermind.server.http.HttpRequestHandler.processRequest(com.evermind.server.ApplicationServerThread, com.evermind.server.http.EvermindHttpServletRequest, com.evermind.server.http.EvermindHttpServletResponse, java.io.InputStream, java.io.OutputStream, boolean)
     void com.evermind.server.http.HttpRequestHandler.run(java.lang.Thread)
     void com.evermind.util.ThreadPoolThread.run()
Question:
- What is the cause of this error message? How to avoid?.
From the Oracle error message documentation:
ORA-00020 maximum number of processes (string) exceeded
Cause: All process state objects are in use.
Action: Increase the value of the PROCESSES initialization parameter.
Another alternative approach may be to configure your Connection pool and/or your ApplicationModule pool to optimize the use of
database connections and/or restrict the number of database connections used by the application. For example, if your application
has declared many root ApplicationModules (i.e. more than one ApplicationModule pool is in use) then it may help to enable the
jbo.doconnectionpooling switch so that each ApplicationModule instance in the pools does not maintain a dedicated database
connection while not in use. Another alternative if you are using the BC4J connection pool (not a JDBC datasource) may be to
restrict the number of connections the pool can create to < 150 with the jbo.maxpoolsize switch. However, please note that this
may have an impact on throughput.
- I intended to deploy my application to 9IAS server. Will the same problem occurs too?.
This is a database issue. So, yes.
Hope this helps.
JR

Error processing XML request, java.lang.IllegalArgumentException

Hi all,
In my code I can successfully connect to server and send the content which is an XML content:
param = java.net.URLEncoder.encode(s, "UTF-8");
java.io.PrintWriter out = new java.io.PrintWriter(connection.getOutputStream());
out.print(param);
Read the response from server:
java.io.BufferedReader in = new java.io.BufferedReader(new java.io.InputStreamReader(connection.getInputStream()));
while((input = in.readLine()) != null)
response += input + "\r";
System.out.println("Client : received : "+response);
Following is the response I receive from server:
Client : received : <html><h1>Error processing XML request</h1>java.lang.IllegalArgumentException: No xml request posted</html>
Has anybody know what the problem is? Why this error is issued?
Any help is greatly appreciated.

Dear legosa,
Thanks so much for the replies. What you wrote makes absolute sence, w/o flush() or close(), it seems that I'm sending only balnk to output!
I don't know how can I fix the 500 Internal Server Error; below is my complete code that does this part, can you tell me if you see sth. wrong in this code?
param = java.net.URLEncoder.encode(aTrans.xmlDoc, "UTF-8");
url = new URL("https://xml.test.surepay.com");
connection = (HttpURLConnection)url.openConnection();
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-type", "application/x-www-form-urlencoded");
String sLen = "" + param.length();
connection.setRequestProperty("Content-length", sLen);
connection.setRequestProperty("Accept", "text/plain");
connection.connect();
System.out.println("Client : Connected");
java.io.PrintWriter out = new java.io.PrintWriter(connection.getOutputStream());
System.out.println("Client : Writing Content");
out.print(param);
out.close();
System.out.println(connection.getURL());
System.out.println(connection.getResponseCode() + " " + connection.getResponseMessage());
System.out.println(connection.getURL());
System.out.println("Client : Waiting for response from Server");
java.io.BufferedReader in = new java.io.BufferedReader(new java.io.InputStreamReader(connection.getInputStream()));
System.out.println("Client : Opened input stream");
while((input = in.readLine()) != null)
response += input + "\r";
System.out.println("Client : received : "+response);

[java.lang.Process] Howto simulate ENTER ?

Similar Messages

Maybe you are looking for