Runtime.exec() odd behaviour.

String p = "smssend 118.sms " +username.trim() +" " +password.trim()
                                       +" " +jTextField1.getText().trim() +" \""
                                            +jTextArea1.getText().trim()+"\"";
            System.out.println(p);
            Runtime rt = Runtime.getRuntime();
            Process proc = rt.exec(p);This is in a try/catch block which also reads in the output from running it.
If I copy and paste the println'd string from this into a shell it works, but when I run the code the program complains of too many arguments if the last one is a string with spaces. Yet in a bash script I use to call the program that's perfectly ok. This is the line in the bash script that would call it:
smssend 118.sms $USERNAME $PASSWORD $PHONE "$MSG" Any ideas? Thanks :)

No one should use Runtime.exec without reading this first:
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html
%

Similar Messages

Urgent Help Required : Java Runtime.exec

Hello,
We are using the java Runtime.exec in the AIX 4.3.3 environment. Java version 1.1.8. We are consuming the output of the Runtime.exec without using the threads. i.e we are doing a readline on the output stream of the runtime and printing it to th standard output in a loop. When this is over we take the error stream and do the same.
We have two problems.
1. A ksh that is run using the java Runtime.exec is showing up multiple processes with the same as a tree structurre when we do a ps.
Why is this ?
2. Also whatever we consume from the standard output/error of runtime and print it to system.out is not being output/error. Any pointers on this ?
Thanks in advance,
Raj.

thanks !
1. we have single thread executing the command. And there are no multiple processes spawned inside the shell script also.
2. I am sorry about the phrasing. Eventhough we are catching the output stream and error stream and dumping the output correspondingly, the process ( the shell script ) hangs ! And this behaviour is sporadic. Please let us know why the process should hang !
Thanks,
rajesh.

Runtime exec IOException issues

Hello,
I have spent two 10 hours days on this problem with countless search permutations and peering into everything from kernel source to java source. Unfortunately, I am not coming up with useful results.
Overview:
I have a very large java application (Apache solr) running on a server with 12GB memory. Without going into too much detail, this application at a point will use a Runtime exec call to fire off a bash shell script. Over time, however, I end up with an IOException "Cannot allocate memory." (More info and stack trace below.)
That application aside I have been able to reproduce this by varying the -Xms and -Xmx jvm parameters with confusing results using the simple program below:
//Use with various -Xms and -Xmx arguments to produce
//IOException on call to Runtime.exec()
import java.io.*;
public class DoRuntime {
   public static void main(String args[]) throws IOException {
      Runtime runtime = Runtime.getRuntime();
      long total = runtime.totalMemory();
      long max = runtime.maxMemory();
      long free = runtime.freeMemory();
      System.out.println("total: " + total);
      System.out.println("max: " + max);
      System.out.println("free: " + free);
      Process process = runtime.exec("/bin/ls");
      InputStream is = process.getInputStream();
      InputStreamReader isr = new InputStreamReader(is);
      BufferedReader br = new BufferedReader(isr);
      String line;
      while ((line = br.readLine()) != null) {
         System.out.println(line);
}Here are some sample runs:
RUN1
rwoodrum@util1wad:~/tmp$ java DoRuntime
total: 188743680
max: 954466304
free: 187759312
DoRuntime.class
DoRuntime.java
rwoodrum@util1wad:~/tmp$
RUN2
rwoodrum@util1wad:~/tmp$ java -Xms10g -Xmx10g DoRuntime
total: 10290069504
max: 10290069504
free: 10236381080
Exception in thread "main" java.io.IOException: java.io.IOException: Cannot allocate memory
        at java.lang.UNIXProcess.<init>(UNIXProcess.java:148)
        at java.lang.ProcessImpl.start(ProcessImpl.java:65)
        at java.lang.ProcessBuilder.start(ProcessBuilder.java:451)
        at java.lang.Runtime.exec(Runtime.java:591)
        at java.lang.Runtime.exec(Runtime.java:429)
        at java.lang.Runtime.exec(Runtime.java:326)
        at DoRuntime.main(DoRuntime.java:14)
rwoodrum@util1wad:~/tmp$
RUN3
rwoodrum@util1wad:~/tmp$ java -Xms10g -Xmx11g DoRuntime
total: 10290069504
max: 10498867200
free: 10236381080
DoRuntime.class
DoRuntime.java
rwoodrum@util1wad:~/tmp$-----
(FWIW, I get the same results replacing /bin/ls with something as lightweight as /bin/true.)
As can be seen in the above output of RUN2, I have set a fixed heap size of 10GB. The jvm seems content with that heap size, but when it goes to exec the child process it becomes rather unhappy. From this I would perhaps conclude that ultimately inside the call to forkAndExec (libjava.so) the call to fork() failed with an ENOMEM. (As a side note, an strace on the process doesn't actually ever show a fork, only a call to clone - which utilizes a fork eventually - more on clone below.)
The results of RUN3, however, seem to imply that the problem is within the jvm itself. In RUN3, I set the initial heap allocation to 10GB, as in RUN2, but I set the maximum at 11GB. One would think (or at least I would) that if the fork in RUN2 failed that it would certainly fail in the case of RUN3. It doesn't.
The manpage of clone indicates that the child process will "share parts of its execution context with the calling process". Indeed, if I'm reading it correctly, it indicates that the child process stack (among other things) is housed in the parent process address space.
Could it be that by setting this very large, fixed heap size as in RUN2, there is no room for the jvm to "maneuver" and properly handle the effort of the Runtime.exec? The fact that RUN3 is successful is what has made me think something like this, but I am by far an expert on how the jvm would handle that sort of thing.
In our production setup of this application, I adjusted the Xmx setting to be something larger than the Xms setting. This worked for a period of time, but eventually produced the same results. I suspect over time the heap simply increased toward the max and again the jvm couldn't do its thing when it came time to RunTime.exec. The fact that this happens on the trivial Runtime.exec program would seem to rule out a memory leak of the production application.
Ultimately something fishy is going on with memory, but with seemingly contradictory results, I am at a loss of where the problem lies.
If I have omittied any potentially relevant information, please let me know. Any thoughts are greatly appreciated.
Some basic system information:
rwoodrum@util1wad:~/tmp$ free
             total       used       free     shared    buffers     cached
Mem:      12304936   12200376     104560          0     337276    7082508
-/+ buffers/cache:    4780592    7524344
Swap:      2097144         32    2097112
rwoodrum@util1wad:~/tmp$ uname -a
Linux util1wad 2.6.18-4-amd64 #1 SMP Mon Mar 26 11:36:53 CEST 2007 x86_64 GNU/Linux
rwoodrum@util1wad:~/tmp$ java -version
java version "1.5.0_10"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_10-b03)
Java HotSpot(TM) 64-Bit Server VM (build 1.5.0_10-b03, mixed mode)-ryan woodrum

I've continued to investigate this with my discoveries below. I've found some more interesting nuances, but am still not satisfied with the explanation of what is going on here. For time reasons, I've capitulated to a somewhat lame workaround.
The test run in the 1.6.0 jvm environment is somewhat revealing in that it confirms that the eventual call to fork (I'm kind of guessing it's the fork call here) is returning an ENOMEM. The 1.5.0 jvm was not returning the actual errno from the call in the JNI code. Checking out $linux_src/include/asm-generic/errno-base.h indeed enumerates ENOMEM to 12.
When I saw this, I started looking at the memory commit inside of /proc/meminfo to see what was going on when I would launch the jvm with the varying Xmx and Xms parameters. Somewhat unsurprisingly at this point, when I would run with large a large heap, the Committed_AS would skyrocket by a proportion roughly equal to the fixed heap size. (See here http://lwn.net/Articles/28345/ for an definition of Committed_AS and other /proc/meminfo fields.)
With the above information in hand, I wanted to confirm without a doubt that the kernel was the thorn in my side. So on a test system I started to play around with the vm_overcommit feature - see $linux_src/Documentation/vm/overcommit-accounting for definitions of modes 0,1, and 2). Sure enough, toying with these modes I was able to alter the behavior of launching the jvm. I switched from the default heuristic mode (0) to an "always overcommit" mode and it would launch and sucessfully fork and exec every time. No surprise there.
What IS surprising, however, is that if, under the default heuristic mode, I specify the jvm parameters differently it will sucessfully run and fork and exec the subprocess. It seems odd to me that at the OS level, specifying `java -Xms4g -Xmx4g` will cause the subprocess fork to fail but specifying `java -Xms4g -Xmx5g` will NOT cause the fork to fail. Running with the latter parameters shows the exact same Committed_AS spike. This all begs the question(s): What's the difference? With a min heap size set to 4g (or whatever) on the both jvm runs, how does a jvm parameter (especially one that allows MORE growth of the heap) impact this call to fork? One variable in the picture at this point that I'm unsure of is the strace call to clone(). I don't know what this could be doing to make things behave differently.
So as I noted, above, I have a relatively lame workaround. Blindly add more swap to increase the CommittedLimit inside the kernel. It'll never get used, it's a waste of space, and, perhaps most importantly, on principal it just rubs me the wrong way.
-ryan woodrum

Runtime.exec and ServerSocket for IPC...blocking problems

I have built an IDE for assembling/deploying web applications.
I am supporting a 'test' mode in the IDE where a compiled 'solution/application' is executed in a separate vm from the IDE using Runtime.exec. For the whole sandbox thing. Don't want a wayward application crashing my IDE.
Naturally I want a way to communicate start/stop from the IDE to the running application. So sockets are my only choice. Calling process.destroy from my IDE won't invoke a shutdownhandler in the generated application's vm, and I want an orderly shutdown as the generated applications open resources/etc.
When I execute the generated application from within the IDE the thread code that creates a server socket blocks in the ServerSocket constructor...why?
When I execute the solution using 'java' outside of my IDE, I can set up a server socket and all works fine.
My IDE is NEVER creating server sockets waiting for client connects...only the generated application does this. So it isn't a case of the IDE already listening for requests on the same port as the server/generated application.
Proving the above is that I can manually start my generated application, start my ide, then invoke the menuitem from the IDE that writes a 'close' byte to the client's socket...and the running application DOES shut down.
Any ideas?

I have decided on a different approach.
At first I thought...ok I have the ServerSocket on the wrong 'side'. I then put the ServerSocket code in the always-running IDE and the Socket code on the running/exec'd application. But still a hang on the running application when constructing the Socket.
I decided instead to call Process.destroy on the running app.
Given that generated app is running in a separate vm, when it shuts down via process.destroy from the ide...although vm shutdown hooks aren't called...I guess it's ok since a destroy of the vm will release all resources. Not as clean as I'd like though.
Additionally, I cannot determine 'true' start of application as no socket notification can be done. I merely determine start after a Runtime.exec of jvm process. Subsequent errors in startup will merely be determined by the IDE in process.waitFor or process.exitValue.
I was getting a wierd socket error when attempting my prior solutions...and not a lot on the web regarding this subject...all relevant posts seemed to be in German/from Germany. Odd. Would need my wife to translate! Mein gott!
I guess I could've communicated from ide to Runtime.exec'd application via a generated file in filesystem...but this seemed cheesy. Sockets should've been used for ipc between java vms...or so I thought.

JVM spawning mysterious child process of itself using Runtime.exec()

Hello, I'm not sure if this is how this is supposed to work but I have a java application that monitors legacy c programs and after a period of time (its intermittent), I'll see a duplicate jvm process running the same classpath, classname as a child of the java application monitor. This behaviour can be reproduced with the following simple class running on either solaris 9 or 10 using 1.6.0_03-b05:
public class Monitor {
Process procss;
public Monitor() {
try {
Runtime runtime = Runtime.getRuntime();
for (int i = 0; i < 10000; i++) {
System.out.println("execing command ls -l.");
procss = runtime.exec("ls -l");
procss.waitFor();
catch (Exception e) {
e.printStackTrace();
public static void main(String[] args) {
new Monitor();
Using java -classpath ./ Monitor to run it. While this is running, at intermittent times doing a ps -ef you will see a duplicate jvm running whose parent process is the one that was started on the command line. Ie:
UID PID PPID etc
user 17434 10706 .... java -classpath ./ Monitor (the one I put running)
user 27771 17434 .....java -classpath ./ Monitor (intermittently started)
in another window I'll run the following shell script that will output the processes when a duplicate java process gets started as they don't seem to run very long (on my production system they will occasionally get hung up until I manually kill them):
#!/usr/bin/ksh
while ((1 == 1))
do
ps -ef | grep "Monitor" | grep -v grep > /tmp/test.out
VAL=`cat /tmp/test.out | wc -l`
if (($VAL != 1))
then
echo "Duplicate java process started"
cat /tmp/test.out
fi
done
It takes roughly 30 seconds before I start to see duplicate jvms starting to run. The concern is that is the new jvm instance running the Monitor class? Eventually on my production system the real application will have a child or 2 linger indefinetly, and threads will be deadlocked. Once I kill these child java processes, everything is back to normal. This doesn't seem to occur with the above java class but will show the duplicate child jvm's start to run after a bit.

This is true for Solaris and Linux. Sun's implementation does a fork. A lot of people who have very large memory java applications wish there was a way to create a process from Java that doesn't involve copying the parent process. As far as I know your stuck.
A workaround: Use jms, rmi, sockets, or files to communicate with a low memory footprint java application whose sole purpose is to spawn child processes.

Runtime.exec() - how to open new window for new program?

Hi,
I have searched through the forums but haven't found an answer to this one yet. I am using runtime.exec() to start up a new java program. At first I thought it wasn't running properly but, after checking task manager, I have discovered that the new program I open runs, it is just completely invisible to me. I am wondering how I can get the new program to run in a command window or something where I can monitor it.
Thank you for your help,
Drew

Thank you all. After trying to figure out why the start command wouldn't work in the runtime.exec() call(not an executable - I am a dolt), I tried putting it in a batch file and it worked perfectly. Thanks for your help,
Drew

How to capture Runtime.exec() output? doesn't seem to work?

This is the first time I've used Runtime.exec();
Here's the code:
Runtime rt = Runtime.getRuntime();
            process = rt.exec(jobCommand);
            BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line=null;
            while((line=input.readLine()) != null) {
                 System.out.println("OUTPUT: " + line);
            int exitVal = process.waitFor();
        } catch(Exception e) {
             e.printStackTrace();
        }//end catchas you can see, this is just copied and pasted out of the standard example for this method.
When it gets to the line:
while((line=input.readLine()) != null)
it doesn't read anything. However, when i run the SAME exact command from the windows CMD prompt i get a ton of output.
what am i doing wrong here?
thanks.

Welcome to the forum!
>
as you can see, this is just copied and pasted out of the standard example for this method.
>
No one can see that - you didn't post a link to the example you said you copied.
>
it doesn't read anything. However, when i run the SAME exact command from the windows CMD prompt i get a ton of output.
>
No one can see what command you are talking about; you didn't post the commnd or even describe what output you expect to get.
>
what am i doing wrong here?
>
What you are doing wrong is not providing the code you are using, the command you are using or enough information about what exactly you are doing.
No one can try to reproduce your problem based on what you posted.

How to display Runtime.exec() command line output via swing

Hi all, I'm new to java but have a pretty good understanding of it. I'm just not familiar with all the different classes. I'm having trouble capturing the output from a command I'm running from my program. I'm using Runtime.exec(cmdarray) and I'm trying to display the output/results to a JFrame. Once I get the output to display in a JFrame, I'd like it to be almost like a java command prompt where I can type into it incase the command requires user interaction.
The command executes fine, but I just don't know how to get the results of the command when executed. The command is executed when I click a JButton, which I'd like to then open a JFrame, Popup window or something to display the command results while allowing user interaction.
Any examples would be appreciated.
Thank you for your help in advance and I apologize if I'm not clear.

You can get the standard output of the program with Process.getInputStream. (It's output from the process, but input to your program.)
This assumes of course that the program you're running is a console program that reads/writes to standard input/output.
In fact, you really should read from standard output and standard error from the process you start, even if you're not planning to use them. Read this:
When Runtime Exec Won't

Using Runtime exec() to open and close process like java or javac

Hi, I m a student who is learning IT and is wondering if
Runtime exec() can run and stop commands like java and javac?
Can someone post the code to do so here?Thank you

Well, Here is my complete code:
import java.util.*;
import java.io.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
class StreamGobbler extends Thread
InputStream is;
String type;
StreamGobbler(InputStream is, String type)
this.is = is;
this.type = type;
public void run()
try
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line=null;
while ( (line = br.readLine()) != null)
System.out.println(type + ">" + line);
} catch (IOException ioe)
ioe.printStackTrace();
class Program implements Runnable
     Process proc;
String args[];
     String[] cmd = new String[4];
     boolean isGone=false;
     public Program(String args[])
          this.args=args;
     public void run()
          if (isGone==true)
               try
                    Runtime.getRuntime().exec(cmd).destroy();
               catch(IOException e)
                    System.out.println("Error: "+e.toString());
               System.out.println("User abort");
     public void start(String args[])
          if (args.length < 1)
System.out.println("USAGE: java GoodWindowsExec <cmd>");
System.exit(1);
try
String osName = System.getProperty("os.name" );
if( osName.equals( "Windows NT" ) )
cmd[0] = "cmd.exe" ;
cmd[1] = "/C" ;
cmd[3] = args[0];
else if( osName.equals( "Windows 95" ) ||osName.equals( "Windows 98" ))
cmd[0] = "command.com" ;
cmd[1] = "/C" ;
cmd[2] = args[0];
                    cmd[3]=args[1];
Runtime rt = Runtime.getRuntime();
// System.out.println("Execing " + cmd[0] + " " + cmd[1]
// + " " + cmd[2]+" "+args[1]);
proc = rt.exec(cmd);
// any error message?
StreamGobbler errorGobbler = new
StreamGobbler(proc.getErrorStream(), "ERROR");
// any output?
StreamGobbler outputGobbler = new
StreamGobbler(proc.getInputStream(), "OUTPUT");
// kick them off
errorGobbler.start();
outputGobbler.start();
// any error???
// int exitVal = proc.waitFor();
//System.out.println("ExitValue: " + exitVal);
} catch (Throwable t)
t.printStackTrace();
     public void destroy()
          isGone=true;
class test1 implements ActionListener
     String s[]={"c:\\jdk1.3\\bin\\java.exe","ContactProcessor1"};
     GUI g=new GUI();
          Program p=new Program(s);
     public test1()
          //didnt work
          g.getStart().addActionListener(this);
          g.getStop().addActionListener(this);
          g.show();
     public void actionPerformed(ActionEvent e)
          if (e.getSource()==g.getStart())
               p.start(s);
               p.run();
          if (e.getSource()==g.getStop())
               p.destroy();
               p.run();
     public static void main(String args[])
          test1 t = new test1();
class GUI extends JFrame
     JButton start;
     JButton stop;
     public GUI()
          super();
          getContentPane().setLayout(new FlowLayout());
          start=new JButton("start");
          stop=new JButton("stop");
          getContentPane().add(start);
          getContentPane().add(stop);
          setSize(100,100);
     public JButton getStart()
          return start;
     public JButton getStop()
          return stop;
}

Error in opening a file with name in chinese characters with Runtime.exec

The issue at hand is when I try to open a file with file name containing chinese characters in a localized environment in Windows through the following java code:
Runtime.exec("rundll32 SHELL32.DLL,ShellExec_RunDLL {File_With_FileName_containing_Chinese_character}");
the following error is thrown by windows.
Cannot open file "C:\??.txt".
with the exception
java.io.IOException: CreateProcess: [Ljava.lang.String;@f5da06 error=2
        at java.lang.Win32Process.create(Native Method)
        at java.lang.Win32Process.<init>(Win32Process.java:66)
        at java.lang.Runtime.execInternal(Native Method)
        at java.lang.Runtime.exec(Runtime.java:566)
        at java.lang.Runtime.exec(Runtime.java:428)
        at java.lang.Runtime.exec(Runtime.java:364)
        at java.lang.Runtime.exec(Runtime.java:326)
        at Launcher.main(Launcher.java:26)
When I try to use the same command (shown below) from the Windows Run command, the file opens sucessfully
rundll32 SHELL32.DLL,ShellExec_RunDLL {File_With_FileName_containing_Chinese_character}
Please suggest.
Thanks in advance

This may be a file association problem. To solve that:
In Windows 7:
1. Right-click the file,
2. Select "Open With"
select [Your Program Here]
3. Check always use this program.
In Windows XP:
1. Locate the file as you have described above
2. Right click the file
3. Select Open with from the pop-up menu
4. Click Choose default program…
5. Select Excel in the Recommended Programs box
6. Check Always use the selected program to open this kind of file
7. Click on OK.
1. Make Excel not available from Office 2007 listed under Programs and Features in Control Panel.
2. Take a registry backup using the steps given here
3. In the registry editor window expand HKEY_CLASSES_ROOT and navigate to .xls right and delete it.
4. Exit Registry Editor
5. Undo Step 1 to make Excel available.
6. Restart the computer and verify it the issue is fixed.
If this answer solves your problem, please check Mark as Answered. If this answer helps, please click the Vote as Helpful button. Cheers, Shane Devenshire

Nokia 6233 v05.10 odd behaviour

Hello!
After thoroughly searching not only this board but the entire Internet, I found no answer to my question so I decided to register and ASK.
I need to know if any of you owners of a Nokia 6233 observed this odd behaviour of your phone - so please keep reading.
I purchased the phone 16 days ago. Being my first Nokia, I took time to exploit its every feature, therefore draining the battery quite quickly. I discharged and fully charged the battery at least 3 times in the first 3 days, without leaving it plugged-in overnight (as far as I know this is no longer necessary). The battery life time increased progressively until a maximum of three days of normal use, meaning moderate talking (under 20 minutes per day), little or no use of Java apps, camera, media players or GPRS/EDGE connection. The screen savers are off, power saver is on, sleep mode is on. Packet data connection - when needed and network mode is GSM only because I do not use 3G. All these should get me the best stand-by time possible, right? Well, they did, until...
I bought a new microSD card, 2.0 GB storage, made by SanDisk. The card works fine, I put my favorite music and video clips on it - all the stuff you do when you have enough space. Since then, the battery life decreased SUBSTANTIALLY to LESS THAN 24 HOURS. And there's more. The battery drains even if the phone is turned off, in roughly the same amount of time. I have never ever seen anything like this. Sometimes the battery is so low that the phone takes a few minutes before displaying the battery charging icon and, when started, it asks for hour/date settings.
So, I need to know if anybody else noticed battery life decrease with bigger memory card capacity, and what's to be done.

Have you tried using the in-box memory card(That came with the phone) again? There's something wrong with your phone and battery if the problem still occurs..
GooD LucKMessage Edited by nj15 on 15-Aug-200704:10 PM

The Runtime.exec methods doesn't work well on Solaris ???

I have two threads and I set the different running time.
I use Runtime.exec to a run the command and use Process to get the process.
It works properly in the windows2000 platform.
However, when I transfer the platform to Solaris...and run the program...
Two threads always at the same time....It is very wired....I always debug
for 2 days....
(at first I run "vmstat 1 2" command, later I change to "ls","rmdir"....etc,
all of them don't work.....
If I close the Runtime.exec..........Everything works well......)
And I study the API. I found this message...
The Runtime.exec methods may not work well for special processes on certain
native platforms, such as native windowing processes, daemon processes,
Win16/DOS processes on Win32, or shell scripts. The created subprocess does
not have its own terminal or console.
Could someone share her/his experience.....:(
And if any other way I can run command inside java code instead of
Runtime.exec.....???
Please reply my mail to [email protected] I do appreciate your kindly &
great help!!!!!!!!
This is my code.......
import java.io.*;
import java.lang.*;
import java.util.*;
* <p>ServerThread1</p>
* <p>??�X???��?�D???�X???, "Vmstat 1 2".</p>
class ServerThread1 extends Thread{
private ServerAgent Sa;
public ServerThread1 (String Name, ServerAgent Sa){
super(Name);
this.Sa = Sa; file://Assign ServerAgent reference Sa
public void run(){
while(true){
try{
Thread.sleep(5000);
catch (Exception e){
System.out.println("ServerThread1 fails");
System.out.println("Thread1 is running.");
try {
Runtime rt1 = Runtime.getRuntime();
Process proc1 = rt1.exec("mkdir"); ------>If I close
rt1.exec , two threads works seperately...........:(
catch (Exception e) {
System.out.println("Thread1 Error");
class ServerThread2 extends Thread{
private ServerAgent Sa;
public ServerThread2 (String Name, ServerAgent Sa){
super(Name);
this.Sa = Sa;
public void run(){
while(true){
try{
Thread.sleep(15000);
catch (Exception e){
System.out.println("ServerThread2 fails");
System.out.println("Thread2 is running.");
try {
Runtime rt2 = Runtime.getRuntime();
Process proc2 = rt2.exec("vmstat 1 2"); ----->If I don't run
the rt2.exe, two threads work seperately....
catch (Exception e) {
System.out.println("Thread2 Error");
public class ServerAgent{
private Vector v1 = new Vector();
private Vector v2 = new Vector();
private Hashtable currentData = new Hashtable();
private static String startUpSwap = null;
private static String startUpMem = null;
public static void main(String[] arg) {
ServerAgent s = new ServerAgent();
ServerThread1 st1 = new ServerThread1("Thread1",s);
ServerThread2 st2 = new ServerThread2("Thread2",s);
st1.start();
st2.start();

If I close the Runtime.exec..........Everything works
well......)You don't empty the output of the command, that blocks the process.
A citation from
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html
Why Runtime.exec() hangs
The JDK's Javadoc documentation provides the answer to this question:
Because some native platforms only provide limited buffer size for standard input and output streams, failure to promptly write the input stream or read the output stream of the subprocess may cause the subprocess to block, and even deadlock.
Try out something like this:
String s;
try {
   Process myProcess =
   Runtime.getRuntime().exec("ls -l"));
   DataInputStream in = new DataInputStream(
          new BufferedInputStream(myProcess.getInputStream()));
    while ((s = in.readLine()) != null) {
        out.println(s);
catch (IOException e) {
    out.println("Error: " + e);
}Another source of trouble under Unix is not having the correct permission for that user that executes the Java VM, which will be the permissions for the spawned subprocess. But this probably not the case, as you see something after exit.
Regards,
Marc

How to give path in Runtime. exec( )

Hi,
I am trying to create an user interface, in which, it should open a different file (for example, example.doc)when a button is clicked in the applet. let us say, the path for example.doc is "C:\\WINDOWS\\DeskTOP\\folder1".
I tried with the following code
Runtime.getRuntime().exec("C:\\WINDOWS\\Desktop\\folder1\\example.doc");
but, when I click on the button it is not opening example file and I am getting an exception. I am using Runtime.exec() command for the first time.Anybody can help me with this???

Since when was a document an executable? The main problem is many people think Runtime.exec () is the same thing as the command line. The answer is, it's not. Typing "example.doc" in the windows terminal emulator (also known as cmd.exe in Windows 2000/XP or command.com in others) will work because example.doc is opened with the application configured to open files with the ".doc" extension.
However, files ending with ".doc" are not executables. If you wish to open a ".doc" file with the associated application, try this: Runtime.getRuntime ().exec ("cmd /c example.doc"); Not that I don't know if this will work with command.com as I haven't tried, but it should work with cmd.exe without problems.
Hope it helps.
Cheers

Runtime.exec() - Need to execute unix command through pipe

I want to execute something like this from Runtime.exec() :
tar -czp -C /tmp/ myfile | ssh -qx -c blowfish remoteHost tar -xz -C /tmp/
If I give the complete string as it is, then the system takes ssh command and the arguments to ssh (-qx) as arguments for tar and, thus, fails. I guess the reason is that the Runtime just takes the first string as the command and passes everything else as arguments to the command.
How can I achieve this?

The pipe symbol is interpreted by the shell, so you'd need the command you execute to be a shell (/bin/sh, /bin/csh /bin/bash, etc.) and the rest of it to be the args to that shell.
Look at the man page for your shell. There should be a -c or somesuch argument that means "take the rest of this line as a command to execute in the shell I'm creating, which will then execute."
Something like /bin/bash -c foo \| bar Not sure if you have to escape the pipe or not. Futz around with it and see.

How can I run Runtime.exec command in Java To invoke several other javas?

Dear Friends:
I met a problem when I want to use a Java program to run other java processes by Runtime.exec command,
How can I run Runtime.exec command in Java To invoke several other java processes??
see code below,
I want to use HelloHappyCall to call both HappyHoliday.java and HellowWorld.java,
[1]. main program,
package abc;
import java.util.*;
import java.io.*;
class HelloHappyCall
     public static void main(String[] args){
          try
               Runtime.getRuntime().exec("java -version");
               Runtime.getRuntime().exec("cmd /c java HelloWorld "); // here start will create a new process..
               System.out.println("Never mind abt the bach file execution...");
          catch(Exception ex)
               System.out.println("Exception occured: " + ex);
} [2]. sub 1 program
package abc;
import java.util.*;
import java.io.*;
class HelloWorld
     public static void main(String[] args){
     System.out.println("Hellow World");
} [3]. Sub 2 program:
package abc;
import java.util.*;
import java.io.*;
class HappyHoliday
     public static void main(String[] args){
     System.out.println("Happy Holiday!!");
} When I run, I got following:
Never mind abt the bach file execution...
I cannot see both Java version and Hellow World print, what is wrong??
I use eclipse3.2
Thanks a lot..

sunnymanman wrote:
Thanks,
But How can I see both programs printout
"Happy Holiday"
and
"Hello World"
??First of all, you're not even calling the Happy Holiday one. If you want it to do something, you have to invoke it.
And by the way, in your comments, you mention that in one case, a new process is created. Actually, new processes are created each time you call Runtime.exec.
Anyway, if you want the output from the processes, you read it using getInputStream from the Process class. In fact, you really should read that stream anyway (read that URL I sent you to find out why).
If you want to print that output to the screen, then do so as you'd print anything to the screen.
in notepad HelloWorld.java, I can see it is opened,
but in Java, not.I have no idea what you're saying here. It's not relevant whether a source code file is opened in Notepad, when running a program.

Runtime.exec() odd behaviour.

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