Runtime Exec on Solaris and wildcards characters

Hello,
I'm trying use exec in the following manner on Solaris 2.8 JDK1.3.1
e.g. exec( "ls /tmp/*.sh" );
When the string contains any sort of punctuation or wildcarding the command doesn't execute, usually fails with RC=2.
exec( "ls /tmp/??.sh" ); fails
exec( "ls /tmp/go.sh" ); works
Any ideas or suggestions?
thanks.

If you haven't found the answer yet, I found it in another article. Basically, * and other wildcards are expanded by the shell so Runtime.getRuntime()exec("ls /tmp/*") won't work. You need to use the String[ ] form of exec(), i.e. Runtime.getRuntime()exec( new String[ ] {"sh", "-c", "ls /tmp/*"} )
hope that helps.

Similar Messages

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)
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class Program implements Runnable
 Process proc;
String args[];
 String[] cmd = new String[4];
 boolean isGone=false;
 public Program(String args[])
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 System.out.println("User abort");
 public void start(String args[])
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System.out.println("USAGE: java GoodWindowsExec <cmd>");
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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]);
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// any error message?
StreamGobbler errorGobbler = new
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// any output?
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outputGobbler.start();
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t.printStackTrace();
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 return start;
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 return stop;
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Very very urgent! Please help about Runtime.exec on Solaris

I wrote a software in Java.
It contains a platform application and a variety of client applicaitons.
Both use Swing MMI. I need my own JRE and invoke client from
platform MMI. On Windows, the software run ok. But on Solaris,
client are always blocked to do work.
Whe run platform and client individually from command line,
client will run ok too. While client is invoked by platform in programm,
it will be blocked to run (client cannot recieve data from RS232).
I noticed that client will continue to run once platform exits.
So I really wonder whether there is something wrong with my codes
to invoke client. Only Solaris invoking codes list here.
public static boolean exec(String execStr) {
    Runtime runtime = Runtime.getRuntime();
    try {
      String[] args = new String[] {
            "/bin/sh", "-c", execStr};
        Process p = runtime.exec(args);
        return true;
      return false;
     catch (Exception e) {
      e.printStackTrace();
    return false;
}

The execStr argment is
/users/devConfig/jre/java -classpath "/users/devConfig/jre/lib:/users/devConfig/lib/ssop.jar:
/users/devConfig/lib/zt103.jar..." zt.client.nsd200v.NSD200VApp ...Where /users/devConfig is my software installed directory, and /users/devConfig/jre is my own packaged JRE1.5.0.

Runtime.exec() - using cp and files with spaces on unix

I'm using the Runtime.exec method to copy files in a unix environment. This works fine until there is a file where the name has spaces in it. I've read the article on the pitfalls of using runtime and how it breaks a string on white spaces and this is what is happening. I've also found another topic that was having the same problem, but they were using /usr/bin/dos2unix. I've tried putting quotes around the filename, but it still breaks on the first space. Any suggestions on how to get around this or another way of doing this would be greatly appreciated.
An example of the os command string is:
/usr/bin/cp /tmp/file with space.doc /docs
Thanks!

Hi!
Well I dont have any Sun machine right here to try this but in windows It works great.
Have you tried something like this ?
import java.io.*;
public class OSCopy {
    public static void main(String[] args) {
        try {
            String space = " ";
            String copycmd = "E:\\cp.cmd";
            String source = "E:\\File with space.txt";
            String destination = "E:\\tmp";
            String cmd = copycmd + space + "\"" + source + "\"" + space + destination;
            System.out.println("cmd: " + cmd);
            Runtime runtime = Runtime.getRuntime();
            Process copy = runtime.exec( cmd );
            BufferedReader reader = new BufferedReader( new InputStreamReader( copy.getInputStream()) );
            String line = null;
            while( (line = reader.readLine()) != null ) {
                System.out.println( line );
        catch (Exception e) {
            e.printStackTrace();
cp.cmd is a simple dos copy command
copy %1 %2
*/good luck!

Runtime.Exec with cmd and problem in waitFor

Hi
I am running
Process p1 = Runtime.getRuntime().exec("cmd /c start /min <some.exe> <args to exe>");
then I am checking
Int ExitVal = p1.waitFor;
If (ExitVal != 0) and so on.
However, the problem is that the p1.waitFor does not really block the thread. It returns 0 and the program continues even though the some.exe has still not completed its execution.
My guess is that Java is giving the exitcode of cmd.exe and not some.exe.
If this analysis is correct, I am stumped. How do I get the exit code of some.exe?
If my analysis is wrong, please help me in the right direction.
Regards
Shreekar

"Enables a user to start a separate window in Windows
from the MS-DOS prompt."
Again, I read it afterwards. However, another funny thing is happening now. Initially my command was
"cmd start /min (some.exe) (some args) > somefile.txt"
(I know I missed to show the output redirection in my original post.)


Then I removed "start /min", it is working as expected.
Then I removed the output redirection and now it hangs !!!
I put back the output redirection and it is working. Does the output redirection make it wait in some way and force it to exit gracefully?

Any ideas?

T2K/T5K type of Solaris servers and Runtime.exec

It is being consistently observed that on T2k/T5k type of Solaris servers (e.g. T5220), the UNIX commands sent from Java using the Runtime class APIs are not being reveived by Solaris. It does not happen always, only occasionally. But when it happens, the java process hang at process.waitFor(). We are using Java1.6.
I read the Java World article "When Runtime.exec() won't" and the behavior we are seeing is not because of any of the known pitfalls mentioned in the article. Also the warning in the Runtime API that speaks about the limited buffer size is also not applicable in this case because we do see it working sometimes. All of a sudden Runtime.exec gets stuck. We have also observed that the problem is not dependent on the command we pass through the Runtime.exec API. It happens for any trivial command.
For more information on the issue, when we execute a 'pstack' on the process id, we see the following output most of the time and the 'truss' output shows the java process to be in a sleeping state:
# pstack 20650
ff2c52d8 lwp_park (0, 0, 0)
ff2bf350 cond_wait_queue (24dd90, 24dd78, 0, 0, 0, 0) + 28
ff2bf770 cond_wait_common (24dd90, 24dd78, 0, 0, 0, 0) + 294
ff2bf874 cond_wait (24dd90, 24dd78, 0, 0, 0, 0) + 10
ff2bf8b0 pthread_cond_wait (24dd90, 24dd78, ff2f3700, 0, f337da00, ecf00000) + 8
eedddacc kernel_delete_session (24dd60, 24dd58, 0, 1, 3, 1c63c) + 114
eeddd7dc kernel_delete_all_sessions (0, 1, 0, 1c8b4, 0, eedfa000) + 98
eedd1eb4 cleanup_library (0, 1, 0, eedfa000, 28180, 3) + 3c
eedd1f1c kernel_fini (0, 1, 0, eedfa000, 28120, eedfa4a4) + 44
eede89e0 _fini (ff3f40fc, ff3f5a70, 2b3f4, 0, ff3f4910, 821) + 4
ff3c54b4 call_fini (ff3f40fc, f43518f0, eede89dc, ff3f42f0, ff3f42a8, ff3f4910) + cc
ff3cfdc0 remove_hdl (f43518f0, f1c4e2bc, 0, 4000, ff300a54, 4821) + ac8
ff3ca408 dlclose_intn (f4351978, ff3f4910, ff3f40fc, 2a520, ff3ca4bc, 0) + 24
ff3ca4e8 dlclose (f4351978, 0, f4350b88, 0, 1c00, 1) + 24
eee33904 pkcs11_slottable_delete (1, f9e2c0, 46ec90, eee46bb0, 0, 1) + 138
eee2e42c pkcs11_fini (eee46b8c, 1, eee2e074, eee46000, 17c18, eee46b84) + 4c
ff241f38 postforkchild_handler (1d18, ff2f3700, 1c00, 4, f337da00, ff2f3700) + 30
ff2b74bc fork (0, 41, 0, f1c4e744, ff2f3700, f337da00) + 144
fe8a8ee4 Java_java_lang_UNIXProcess_forkAndExec (ffffffff, 0, fee0c0, fe8c4000, 4, 2) + 6d0
f940bc20 * java/lang/UNIXProcess.forkAndExec([B[BI[BI[BZLjava/io/FileDescriptor;Ljava/io/FileDescriptor;Ljava/io/FileDescriptor;)I+-20552
f940bbc4 * java/lang/UNIXProcess.forkAndExec([B[BI[BI[BZLjava/io/FileDescriptor;Ljava/io/FileDescriptor;Ljava/io/FileDescriptor;)I+0
f94058b8 * java/lang/UNIXProcess.<init>([B[BI[BI[BZ)V+62
f9405764 * java/lang/ProcessImpl.start([Ljava/lang/String;Ljava/util/Map;Ljava/lang/String;Z)Ljava/lang/Process;+182
f9405874 * java/lang/ProcessBuilder.start()Ljava/lang/Process;+112
f9405874 * java/lang/Runtime.exec([Ljava/lang/String;[Ljava/lang/String;Ljava/io/File;)Ljava/lang/Process;+16

If you haven't found the answer yet, I found it in another article. Basically, * and other wildcards are expanded by the shell so Runtime.getRuntime()exec("ls /tmp/*") won't work. You need to use the String[ ] form of exec(), i.e. Runtime.getRuntime()exec( new String[ ] {"sh", "-c", "ls /tmp/*"} )
hope that helps.

Best way to close a Runtime.exec() process and how to handle closing it?

I have multiple Runtime.exec() Processes running and am wondering what the best way it is to close them and take care of closing the resources. I see that Process.destroy() seems to be the way to terminate the Process - is finalize() the best way to close anything in that Process?
Thanks

I was involved with your other thread, so I think I know what you are trying to do.
All Dr's answers are correct.
Now you have a program A written by you that does Runtime.exec() of multiple instances
of another program B written by you. You want A to somehow tell B to exit.
You must use some kind of Inter Process Communication. If this is the only interraction
between the two programs I can suggest two options. If you anticipate more
interraction, you may want to look at other means (RMI, for instance, which was proposed
by EJP in the other thread for starting B, is also useful in exchanging info).
Solution 1:
Start a thread in B and read stdin. A will write to stdin a command, such as QUIT.
When B reads it, it does System.exit().
Solution 2:
Start a SocketServer in B that accepts connections on a separate thread.
When A wants B to exit, it connects to it and writes a command such as QUIT.
When B reads it, it does System.exit().
You may note that QUIT is not the only command you can send from A to B, in case you will need more.
Edited by: baftos on Nov 5, 2007 2:15 PM

Java RunTime.exec in a JFrame?

Dear all,
Is it possible to run an external program (such as open an PDF file, or executing a program from Windows Command Prompt) by Runtime.exec(open.bat), and show the pdf file (or Command Prompt windows) inside a JFrame or JPanel ?
Thanks!

I don't know of any solution for you.
But talk to Adobe instead, maybe they have something which you can use to render PDF-files in java.

Runtime.exec on Mac

How to use runtime.exec on Mac. I need to start iCal and I don't know how. calling runtime.exec("iCal") , runtime.exec("/Applications/iCal") and runtime.exec("/Applications/iCal.app") throws error. Please help. I don't know anything about Mac.

Yes I did the second way and it gives a runtime
error. I wrote a program that accepts argument and
then executes it using getRuntime().exec(argument);
I am still not able to start any programs under Mac.
The problem is that I don't know anything about Mac.Suggestion.
Figure out how to launch it from the terminal. That should give you an idea of what the command should be I think.
Sorry I can't remember OTOH how to get into the terminal but I know you can.

Running java process in a while loop using Runtime.exec() hangs on solaris

I'm writting a multithreaded application in which I'll be starting multiple instances of "AppStartThread" class (given below). If I start only one instance of "AppStartThread", it is working fine. But if I start more than one instance of "AppStartThread", one of the threads hangs after some time (occasionaly). But other threads are working fine.
I have the following questions:
1. Is there any problem with starting a Thread inside another thread?. Here I'm executing the process in a while loop.
2. Other thing i noticed is the Thread is hanging after completing the process ("java ExecuteProcess"). But the P.waitFor() is not coming out.
3. Is it bcoz of the same problem as given in Bug ID : 4098442 ?.
4. Also java 1.2.2 documentation says:
"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. "
I'm running this on sun Solaris/java 1.2.2 standard edition. If any of you have experienced the same problem please help me out.
Will the same problem can happen on java 1.2.2 enterprise edition.?
class AppStartThread implements Runnable
public void run()
while(true)
try
Process P=Runtime.getRuntime().exec("java ExecuteProcess");
P.waitFor();
System.out.println("after executing application.");
P.destroy();
P = null;
System.gc();
catch(java.io.IOException io)
System.out.println("Could not execute application - IOException " + io);
catch(java.lang.InterruptedException ip)
System.out.println("Could not execute application - InterruptedException" + ip);
catch (Exception e)
System.out.println("Could not execute application -" + e.getMessage());

I'm writting a multithreaded application in which I'll
be starting multiple instances of "AppStartThread"
class (given below). If I start only one instance of
"AppStartThread", it is working fine. But if I start
more than one instance of "AppStartThread", one of the
threads hangs after some time (occasionaly). But other
threads are working fine.
I have the following questions:
1. Is there any problem with starting a Thread inside
another thread?. Here I'm executing the process in a
while loop.Of course this is OK, as your code is always being run by one thread or another. And no, it doesn't depend on which thread is starting threads.
2. Other thing i noticed is the Thread is hanging
after completing the process ("java ExecuteProcess").
But the P.waitFor() is not coming out.This is a vital clue. Is the process started by the Runtime.exec() actually completing or does the ps command still show that it is running?
3. Is it bcoz of the same problem as given in Bug ID :
4098442 ?.
4. Also java 1.2.2 documentation says:
"Because some native platforms only provide limited
ed 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. "These two are really the same thing (4098442 is not really a bug due to the reasons explained in the doc). If the program that you are exec'ing produces very much output, it is possible that the buffers to stdout and stderr are filling preventing your program from continuing. On Windows platforms, this buffer size is quite small (hundreds of characters) while (if I recall) on Solaris it is somewhat larger. However, I have seent his behavior causing problem on Solaris 8 in my own systems.
I once hit this problem when I was 'sure' that I was emitting no output due to an exception being thrown that I wasn't even aware of - the stack trace was more than enough to fill the output buffer and cause the deadlock.
You have several options. One, you could replace the System.out and System.err with PrintStream's backed up by (ie. on top of) BufferedOutputStream's that have large buffers (multi-K) that in turn are backed up by the original out and err PrintStream's. You would use System.setErr() and System.setOut() very early (static initializer block) in the startup of your class. The problem is that you are still at the mercy of code that may call flush() on these streams. I suppose you could implement your own FilterOutputStream to eat any flush requests...
Another solution if you just don't care about the output is to replace System.out and System.err with PrintStreams that write to /dev/nul. This is really easy and efficient.
The other tried and true approach is to start two threads in the main process each time you start a process. These will simply consume anything that is emitted through the stdout and stderr pipes. These would die when the streams close (i.e. when the process exits). Not pretty, but it works. I'd be worried about the overhead of two additional threads per external process except that processes have such huge overhead (considering you are starting a JVM) that it just won't matter. And it's not like the CPU is going to get hit much.
If you do this frequently in your program you might consider using a worker thread pool (see Doug Lea's Executor class) to avoid creating a lot of fairly short-lived threads. But this is probably over-optimizing.
Chuck

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

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.*;
* ServerThread1
* ??�X???��?�D???�X???, "Vmstat 1 2".
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

Runtime.exec() and fork() and Process

So let me see if I understand this correctly, and if I don't please fill me in. If I call the following piece of codeRuntime.getRuntime().exec("chgrp rcsweb " + path+fs+orgName);
Runtime.getRuntime().exec("chmod 660 " + path+fs+orgName);where path is the real path to a file, fs is short for File.spearator and orgName is the name of a file, then in the Unix environment, it will fork off a process.
First, I seem to remember one forum topic that mentioned not forgetting about killing the process returned by exec, so I guess I need to add that to my code.
Second, since I am forking off this process inside of a J2EE container, am I actually forming off the entire container, or just the Servlet where Runtime is called, or what?
Third, how can I prevent the error java.io.IOException: Not enough space
at java.lang.UNIXProcess.forkAndExec(Native Method)
at java.lang.UNIXProcess.<init>(UNIXProcess.java:54)
at java.lang.Runtime.execInternal(Native Method)
at java.lang.Runtime.exec(Runtime.java:546)
at java.lang.Runtime.exec(Runtime.java:413)
at java.lang.Runtime.exec(Runtime.java:356)
at java.lang.Runtime.exec(Runtime.java:320)when I do not have the option of changing my VM size? Is killing the Process (and using waitFor()) going to take care of this issue?
I appreciate your help.

OK, after writing a few test programs, it is indeed clear..on unix (at least on solaris) when calling runtime.exec(..) The ENTIRE VM does indeed get forked. Therefore if your current Memory allocation for you VM is sitting at say 64MB (or you initial memory setting), another 64MB process will be created, even if you doing something as a simple
exec("ls");
I also tried putting runtime.exec call in its own thread hoping that if it was not in the main thread, that only that process would be forked..to no avail..the entire vm is indeed forked everytime...making runtime.exec damn near useless for server side work, and very dangerious..as you can essentialy assume you always need 2x your memory requirements.
If anyone has figured out a workaround...any suggestions greatly appreciated.
Some thoughts on some work-arounds
1. Run 2 VMs (then when native calls are required..send a message to the 'native-calling vm' (insure its memory footprint is very low)
2. Write your exec method via JNI (or does JNI calls also result in a fork of the vm on unix..)
Test code below (threaded version)
import java.util.*;
import java.io.*;
public class test5 extends Thread
 public void run()
 int loops = 0;
 while (true)
 loops++;
 System.out.println("---- iteration " loops "---");
 makeNativeCall();
 public static void main(String[] args)
 try
 System.out.println("testing on OS: " + System.getProperty("os.name"));
 // Allocate a nice chunk of memory
 byte[] bytes = new byte[1024 * 1000 * 50];
 test5 tst = new test5();
 tst.start();
 while (true)
 Thread.sleep(1000);
 catch(Exception e)
 {e.printStackTrace();}
public void makeNativeCall()
 Runtime runtime = Runtime.getRuntime();
InputStream stderr = null;
InputStream stdout = null;
 OutputStream stdin = null;
Process proc = null;
long totalMem = (long)(runtime.totalMemory()/1024);
long freeMem = (long)(runtime.freeMemory()/1024);
long usedMem = (long)((totalMem - freeMem));
System.out.println("VM REPORT: TOTAL(" totalMem") FREE("+freeMem+") USED(" usedMem")" );
try
proc = runtime.exec("sleep 1");
stderr = proc.getInputStream();
stdout = proc.getErrorStream();
stdin = proc.getOutputStream();
String line = null;
int i = 0;
String error = "";
int exitVal = proc.waitFor();
if (exitVal != 0)
System.out.println("ERROR " +exitVal);
System.out.println("DETIAL" +error);
catch(Exception e)
e.printStackTrace();
finally
if (stderr != null)
try{stderr.close();}catch(Exception ignore){ignore.printStackTrace();}
 if (stdout != null)
try{stdout.close();}catch(Exception ignore){ignore.printStackTrace();}
 if (stdin != null)
try{stdin.close();}catch(Exception ignore){ignore.printStackTrace();}
if (proc != null)
try{proc.destroy();}catch(Exception ignore){ignore.printStackTrace();}

Runtime.exec() and batch files

I am having a problem on Windows 2000 while trying to execute a batch file with the Runtime.exec() method. Basically, the exit value returned from the call to Runtime.exec(), returned specifically by the waitFor() method in the Process class, is always zero, even if the batch file fails miserably. After looking into batch files further, it seems to me that the only way to get the exit value of the commands run in the batch file back to the Runtime.exec() call is to put "EXIT %ERRORLEVEL%" in the batch file. What this actually does is exit the command(cmd) shell that the batch file was running in with the exit code of the last command run. This is all great when calling the batch file with a Runtime.exec() call, but when you run it in a cmd window, the window closes when the batch file completes, because the call to EXIT exits the entire shell. I guess i'm just wondering, am i correct in assuming the exit value returned to the java process is going to be the exit value of the shell in which the batch file is running? I need to have the exit value actually indicate whether the batch file ran successfully or not, and if i have to put in the EXIT %ERRORLEVE% (which exits the cmd shell with the exit value of the last command run), then i'll do that, but if someone knows a better way of doing this, i am all ears. Thanks in advance

To run any command from java code, the method is
Runtime.getRuntime().exec( myCommandString )
Where, myCommandString is something like "/full/pathname/command".
If the pathname contains spaces (specifically in Windows), e.g. "c:\program files\windows\notepad", then enclose it in quotes within the quoted string. Or pre-tokenize them into elements of an array and call exec(String[] cmd) instead of exec(String cmd).
From JDK1.3 there are two new overloaded Runtime.exec() methods. These allow you to specify starting directory for the child process.
Note, there is a gotcha associated with reading output from commands. When the runtime exec's the process, it passes to it 3 streams, for stdin, stdout, and stderr; the out and err are buffered but the buffer size isn't very big. When your process runs, it reads (if needed) from in, and writes to out and err.
If it doesn't write more than the buffer-size, it can run to completion.
But if it tries to write more data to one or the other stream than the buffer can hold, the write blocks, and your process hangs, waiting for you to empty the buffer so it can write some more.
So after the exec call, get the streams, and read from them in a loop until they both hit end-of-stream (don't block on either one, just read whatever is available from each, each loop iteration).
Then when the streams have ended, call the process.waitFor() method to let it finish dying.
Now, here is a code snippet how you achieve this.
String strCommand = "cmd.exe /c " + strCommand;
// For Solaris / unix it will be
// String strCommand = "/usr/cobra/sol/runInstaller.sh";
boolean bWait = true;
//execute the command
try
     Runtime r = Runtime.getRuntime();
     Process pr = r.exec(strCommand);
     Process pr = r.exec(callAndArgs);
     BufferedInputStream bis =new BufferedInputStream(pr.getInputStream ());
     int c=0;
     /** Outlet for IO for the process **/
     while (c!=-1)
          c=bis.read();
     /**Now wait for the process to get finished **/
     if(bWait == true)
          pr.waitFor();
          pr.destroy();
catch(Exception e)
     System.out.println("Could not execute process " + strCommand);
     return(false);

To jschell How to get data System properties by JNI and Runtime.exec()

Thank you very much for answer. ummm....but I'm can not gets data system properties by JNI or Runtime.exec(). Please help me. I'm want create Java-Applet for data System properties ( memory quantity?, Harddisk capacity?, CPU speed ?, Printer Name? and all hardwares ) in my computer. It very important for me. Help me please. thank you..

Java applets are restricted to accessing only some system properties - and it is good so. I would not be happy if any applet could inquire about, say, my user name or the amount of memory in my box.

Runtime Exec on Solaris and wildcards characters

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