Process.exitValue() ??

Hello,
I have a runscript method in a java class. The method will return the exitValue after calling the runtime.exec(). Since I have to capture the exception, which int value can I return to indicate the exception?
I checked the javadoc it only says exitvalue 0 means no error. I need to know the the possible numbers process.exitValue can return in order to avoid them in my return value at the catch clause.
Any idea?
Thanks in advance.
Tiana

I would suggest that you throw the exception again after you catch one in your catch block. This is a way that more 'java'. And you don't have to worry what the exitValue will be.
If you really want to return an integer, I would use -1 because it is normally used as an indication of abnormal return.
PC

Similar Messages

Process.exitValue() only returns the low byte of the exit code?

Hi - I'm executing a subprocess and then waiting for it to return, and then examining the exit code of the subprocess. The error the subprocess returns is 0xb03, but exitValue() only sees 0x03. Further testing shows that if I return 0xbff from my native process, exitValue() or waitFor() will only return 0xff. I expanded this further to return 0xfffffbff, and sure enough, the Process methods only return 0xff.
Anyone know what the deal is here? The return type for exitValue() and waitFor() are both 'int', so it seems reasonable to be able to return values up to 0xffffffff. Is there a way to set this up to sue the full int?
Thanks for any insight.

OK, that explains it. I think we had taken the fact that main() returns and int on *NIX that you could return anything that fit in an int into the exit code. I've now found some corroboration that you can only return a value of 0-255.
This also explains why we have never seen this issue on Windows - apparently you can return much larger values on Windows.
Thanks for the assist!

Error in creating a process using runtime class - please help

Hi,
I am experimenting with the following piece of code. I tried to run it in one windows machine and it works fine. But i tried to run it in a different windows machine i get error in creating a process. The error is attached below the code. I don't understand why i couldn't create a process with the 'exec' command in the second machine. Can anyone please help?
CODE:
import java.io.*;
class test{
public static void main(String[] args){
try{
Runtime r = Runtime.getRuntime();
     Process p = null;
     p= r.exec("dir");
     BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
     System.out.println(br.readLine());
catch(Exception e){e.printStackTrace();}
ERROR (when run in the dos prompt):
java.io.IOException: CreateProcess: dir error=2
at java.lang.Win32Process.create(Native Method)
at java.lang.Win32Process.<init>(Win32Process.java:63)
at java.lang.Runtime.execInternal(Native Method)
at java.lang.Runtime.exec(Runtime.java:550)
at java.lang.Runtime.exec(Runtime.java:416)
at java.lang.Runtime.exec(Runtime.java:358)
at java.lang.Runtime.exec(Runtime.java:322)
at test.main(test.java:16)
thanks,
Divya

As much as I understand from the readings in the forums, Runtime.exec can only run commands that are in files, not native commands.
Hmm how do I explain that again?
Here:
Assuming a command is an executable program
Under the Windows operating system, many new programmers stumble upon Runtime.exec() when trying to use it for nonexecutable commands like dir and copy. Subsequently, they run into Runtime.exec()'s third pitfall. Listing 4.4 demonstrates exactly that:
Listing 4.4 BadExecWinDir.java
import java.util.*;
import java.io.*;
public class BadExecWinDir
public static void main(String args[])
try
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec("dir");
InputStream stdin = proc.getInputStream();
InputStreamReader isr = new InputStreamReader(stdin);
BufferedReader br = new BufferedReader(isr);
String line = null;
System.out.println("<OUTPUT>");
while ( (line = br.readLine()) != null)
System.out.println(line);
System.out.println("</OUTPUT>");
int exitVal = proc.waitFor();
System.out.println("Process exitValue: " + exitVal);
} catch (Throwable t)
t.printStackTrace();
A run of BadExecWinDir produces:
E:\classes\com\javaworld\jpitfalls\article2>java BadExecWinDir
java.io.IOException: CreateProcess: dir error=2
at java.lang.Win32Process.create(Native Method)
at java.lang.Win32Process.<init>(Unknown Source)
at java.lang.Runtime.execInternal(Native Method)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at BadExecWinDir.main(BadExecWinDir.java:12)
As stated earlier, the error value of 2 means "file not found," which, in this case, means that the executable named dir.exe could not be found. That's because the directory command is part of the Windows command interpreter and not a separate executable. To run the Windows command interpreter, execute either command.com or cmd.exe, depending on the Windows operating system you use. Listing 4.5 runs a copy of the Windows command interpreter and then executes the user-supplied command (e.g., dir).
Taken from:
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html

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 ^^

Killing a running process

hi all,
what my task is , i have to write java code to close a running application in my windows.
for this , i wrote the following code.
but it is not working.
can anybody help?
Process process = null;
        try {
        System.out.println ("Before execute mozilla");
        String str[]={"net.exe","stop","C:\\Program Files\\Mozilla Firefox\\firefox.exe"};
        process = Runtime.getRuntime().exec(str);
        System.out.println ("After execute mozilla, sleep for 5 seconds");
        Thread.sleep (5000);
        System.out.println ("Wake up, trying to kill mozilla");
        process.destroy();
        System.out.println ("mozilla killed!");
        System.out.println(process.exitValue());
        } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        } it is not showing error , but it is not working..
Edited by: jvarmad on Nov 9, 2008 11:31 PM

I've had this before on Windows as well, and don't really know why the processes don't go away (at least not always), but if you add a finally block and do a "process.exitValue()", you may (and probably will, in this case) get an exception (so catch it), but after that the process is (usually) gone.
I know, this is nothing but a hack, half, work-around, but it at least seems to work, most of the time.
In any case, try to stay away from Runtime.exec unless absolutely necessary, and for opening a browser (as of 1.6) it is not. Use the Desktop class (see the API docs).

What does an exitValue of 255 signify?

Process proc = Runtime.getRuntime().exec("FileName");
int exitVal = proc.waitFor();
System.out.println("Process exitValue: " + exitVal);
Here I am getting an exit value of 255 printed out. I am working on WindowsNT4.0. Could anyone please explain what error this number signifies?

As prior posters have pointed out an exit code other than 0 typically indicates an error. And applications assign different meanings to error codes; there really aren't any standards. That said, exit code 255 often indicates an abnormal termination e.g., application was killed.

Vm.process().getInputStream().read() hangs if the VM is suspended?

I use a LaunchConnector to launch a application. When I was using the vm.process().getInputStream().read() method to read the output of the application, I found the read() method blocked if the VM is suspended. However , after the VMDeathEvent ,the read() method run smoothly. Is that means if I want the output I must wait for the completion of the application?
I'm writing a debug tools . I want to get the output message while the application is being debuged.
Below are simple codes for my problem:
public class MyTest {
     public static void main(String[] args){
          List connectors = Bootstrap.virtualMachineManager().allConnectors();
          LaunchingConnector lc=findLaunchingConnector(connectors);
          Map arguments=lc.defaultArguments();
Connector.Argument mainArg=(Connector.Argument)arguments.get("main");
VirtualMachine vm;
mainArg.setValue("fore");//fore is a simpl application
try {
     vm=lc.launch(arguments);
     vm.resume();//if this is removed,the next code will be blocks
vm.process().getInputStream().read();
}catch(Exception e){
     throw new Error("can't launch the application");//ignore for simplification
     public static LaunchingConnector findLaunchingConnector(List cs){
          Iterator iter=cs.iterator();
          while(iter.hasNext()){
               Connector c=(Connector)iter.next();
               if(c.name().equals("com.sun.jdi.CommandLineLaunch"))
                    return (LaunchingConnector)c;
          return null;
}

hello,
thank you for your answer!
When i try to read the stream nevertheless:
process.getInputStrem().read() = -1
There ist still another thing, which I understand...
process.exitValue() is 13. Which for an error could be it??
regards,
Joana

Always returns exitvalue of 1 in Linux

Hi,
I am facing a problem with Linux. I am executing a process in Linux machine and getting the return value using Process.exitValue(). Even though the error happens, it always returns 1. I tried with the jdk version 1.5.0_11. Please help me.
Code Snippet
Process p = Runtime.getRuntime().exec("/bin/mv");
int exitCode = p.exitValue();
System.out.println(" exit code : "+exitCode);
Thanks in Advance

Since just giving a command "mv", it should fail and
the exitValue should be 1 (for failure). Instead it
always returns 0. But, It works good in Solaris.You have not read the thread! You need to use int returnCode = process.waitFor();rather than int returnCode = process.exitValue();because you need to give the process a chance to complete.

Always returns exitvalue of 1

Hi,
I am facing a problem with Linux. I am executing a process in Linux machine and getting the return value using Process.exitValue(). Even though the error happens, it always returns 1. I tried with the jdk version 1.5.0_11. Please help me.
Code Snippet
Process p = Runtime.getRuntime().exec("/bin/mv");
int exitCode = p.exitValue();
System.out.println(" exit code : "+exitCode);
Thanks in Advance

Since just giving a command "mv", it should fail and
the exitValue should be 1 (for failure). Instead it
always returns 0. But, It works good in Solaris.You have not read the thread! You need to use int returnCode = process.waitFor();rather than int returnCode = process.exitValue();because you need to give the process a chance to complete.

Send password to process

Hi,
There is application called blabla.exe. If I type blabla.exe in command prompt, it will asked password.
C:\>blabla.exe
Password:
In java, I create blabla.exe process by this code:
Process p = Runtime.getRuntime().exec("blabla.exe");The question is how do I send "password" programmatically to "blabla.exe" process that created by my java class???

how do i do that??? I try this code:
Process p = Runtime.getRuntime().exec("blabla.exe");
String password = "superman";
OutputStream outputStream = p.getOutputStream();
outputStream.write( password.getBytes() );
outputStream.close();Is it true???? It fail anyway.....
anyway.... I try the code from http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html....
import java.util.*;
import java.io.*;
public class MediocreExecJavac
    public static void main(String args[])
        try
            Runtime rt = Runtime.getRuntime();
            Process proc = rt.exec("javac");
            InputStream stderr = proc.getErrorStream();
            InputStreamReader isr = new InputStreamReader(stderr);
            BufferedReader br = new BufferedReader(isr);
            String line = null;
            System.out.println("<ERROR>");
            while ( (line = br.readLine()) != null)
                System.out.println(line);
            System.out.println("</ERROR>");
            int exitVal = proc.waitFor();
            System.out.println("Process exitValue: " + exitVal);
        } catch (Throwable t)
            t.printStackTrace();
}I change javac to java.... But it hangs after this line:
System.out.println("<ERROR>");
In br.readLine(), I think....
What is the problem??? java 1.5.0 in windows xp.

Process.destroy() is ignored

Hi all,
I have a problem using the method destroy() from class Process.
I created a simple thread as a class which implements interface Runnable. In method run() I start an external command using ProcessBuilder.start(). The command which is started writes output to stdout in an endless loop. I consume this output using class Scanner which iterates line-by-line through the stream displaying it by System.out.println().
If I try to stop the process with method destroy() nothing really happens. I checked Process.exitValue() which throws an IllegalThreadStateException saying that the process has not exited.
I searched the internet and found something about this problem: A process could only be destroyed if it does not write to stdout anymore. Is that true, because my process acts like an endless loop writing to stdout...
Thanks in advance
public class Starter implements Runnable {
    private volatile Thread thisThread;
    private ProcessBuilder processBuilder;
    private Process process;
    private Scanner scanner;
    public void start() {
        thisThread = new Thread(this);
        thisThread.start();
    public void stop() {
        thisThread.interrupt();
        process.destroy();
        System.out.println("EXIT: " + process.exitValue());
    public void run() {
        try {
            processBuilder = new ProcessBuilder("myCommand");
            processBuilder.redirectErrorStream(true);
            process = processBuilder.start();
            scanner = new Scanner(process.getInputStream());
            while (scanner.hasNextLine()) {
                String input = scanner.nextLine();
                System.out.println("Line: " + input);
            scanner.close();
        } catch (IOException e) {
            e.printStackTrace();
}

Thanks for the reply. I made the following changes:
    public void stop() {
        process.destroy();
        try {
            Thread.sleep(2000); // needed, otherwise the exception mentioned before is thrown
        } catch (InterruptedException e) {
            e.printStackTrace();
        thisThread.interrupt();
        System.out.println("EXIT: " + process.exitValue());
    }This code throws no exception anymore. I get a value from exitValue(). But my process is still running: I tried this without using method thisThread.interrupt(). The scanner should actually stop, because there is no further input to process.
Also a ps (I'm working on Linux) still shows my process.

Runtime.exec child process - C program, I/O blocked???

Hi i'm meeting this interesting problem. I am running a simple C app from a Java app as a child process. I want to read/write both the Input and Output before the child process is finished but especially the output of the C app seems to be bloked before the process is finsished and thus i can not make any dialogue with the app when needed?
Any ideas...., here's the source
try
String[] command={"cmd","/c","prog.exe"};
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(command);
InputStream stderr = proc.getInputStream();
/*String str="123";
BufferedOutputStream bufStr= (BufferedOutputStream) proc.getOutputStream();
bufStr.write(123);
bufStr.flush();*/
InputStreamReader isr = new InputStreamReader(stderr);
BufferedReader br = new BufferedReader(isr);
String line = null;
while ( (line = br.readLine()) != null)
System.out.println(line);
PrintWriter out = new PrintWriter(new OutputStreamWriter(proc.getOutputStream()), true);
out.write("qwer");
out.flush();
int exitVal = proc.waitFor();
System.out.println("Process exitValue: " + exitVal);
} catch (Throwable t)
Another thing - when it reaches to reading the output of the C app , the execution of main is suspended and it hangs indefinitely....?
thanks a lot , it really bugs me.....

As for
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-
traps.html?page=4 ,
i have read it a couple of times and digested it:),
tryed a couple of things but i can't say anything
there solves my problem. If you have anything
particular in your mind please, please specifuy or
quote in the post....How can I ! You don't show your latest code and your original code needed changing so that it implemented the guidelines in the reference.
>
And one more thing , i am pretty sure that the
problem is in the fact that the .exe prog blocks its
out stream until finishing, i'm working on why and
how to undo it....Since I don't have access to the source code of your exe and I don't have the source code of your java and I don't have your problem with executing any of my exe files then I can't comment. And, yes my exe files do write to stdin, read from stdout and read from stderr. I also use the same approach with perl and python scripts.

Last line is still not read

Hi,
I fixed error in last post and rewrote the code using ProcessBuilder instead.
Output from my unix tool is:
Command is a shell application' /home/myid/test/myshell/bin/run' that starts a ascii gui that looks like ( see below). It waits for input from user.
*   My shell Application                   *
HELP: h
COMMAND: c
QUIT:q
135.19.45.18>
And still the last line is not showing when I read the text.
I have tried with readLine() and I get the same error.
Note: When I debug, after characters in line:
OUIT:q
have been read I can see that debugger hangs on
br.read()
And now the code looks like:
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
public class RunShellCmd {
    private BufferedReader processInputStream;
    private BufferedWriter processWriter;
    public static void main(String args[]) throws Exception {
        RunShellCmd cmd = new RunShellCmd();
        cmd.runCmd();
    public void runCmd() throws Exception {
        Process process = null;
        List<String> cmd = new ArrayList<String>();
        cmd.add("/bin/bash");
        cmd.add("/home/myid/test/myshell/bin/run");
        ProcessBuilder processBuilder = new ProcessBuilder(cmd);
        processBuilder.redirectErrorStream(true);
        try {
            System.out.println("start process ....");
            process = processBuilder.start();
            InputStream is = process.getInputStream();
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            StringBuilder sb = new StringBuilder();
            int intch;
            while ((intch = br.read()) != -1) {
              char ch = (char) intch;
              sb.append(ch);
              System.out.println(sb.toString());
        } catch (IOException e) {
            System.out
                    .println("An error occourd: "
                            + e.toString());
        } finally {
            processInputStream.close();
            process.destroy();
            System.out.println("exit value: " + process.exitValue());
            processWriter.close();

DUPLICATE THREAD!
Please don't create duplicate threads. You already have a thread for this same issue.
I fixed error in last post and rewrote the code using ProcessBuilder instead.
Good - then post your progress in the original thread and keep using it until the problem is resolved. That way the people that tried to help you before can see the entire context of what you are trying.
https://forums.oracle.com/thread/2611844

Error while trying to execute a unix shell script from java program

Hi
I have written a program to execute a unix shell script in a remote machine. I am using J2ssh libraries to estabilish the session connection with the remote box.The program is successfully able to connect and authenticate with the box.
The runtime .exec() is been implemented to execute the shell script.I have given below the code snippet.
try {
     File file_location = new File("/usr/bin/");
     String file_location1 = "/opt/app/Hyperion/scripts/daily";
     String a_mib_name = "test.sh";
     String cmd[] = new String[] {"/usr/bin/bash", file_location1, a_mib_name};
     Runtime rtime = Runtime.getRuntime();
     Process p = rtime.exec(cmd, null, file_location);
System.out.println( "Connected to the server1" );
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = br.readLine();
while(line !=null)
System.out.println(line);
line = br.readLine();
br.close();
p.getErrorStream ().close ();
p.getOutputStream().close();
int retVal = p.waitFor();
System.out.println("wait " + retVal);
//session.executeCommand("ls");
catch (IOException ex) {
I get an error message
Connected to the server
java.io.IOException: Cannot run program "/usr/bin/bash" (in directory "\usr\bin"
): CreateProcess error=3, The system cannot find the path specified
at java.lang.ProcessBuilder.start(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at SftpConnect.main(SftpConnect.java:143)
Caused by: java.io.IOException: CreateProcess error=3, The system cannot find th
e path specified
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.<init>(Unknown Source)
at java.lang.ProcessImpl.start(Unknown Source)
I am sure of the file path where the bash.sh and test.sh are located.
Am i missing something? Any help would be greatly appreciated.
Thanks
Senthil

Hi, I am using a simple program to connect to a RMI server and execute shell script. I use the Runtime.exec aommand to do the same.
The script is sh /tmp/pub/alka/test.sh /tmp/pub/alka/abc/xyz/ul ul
The script when run from the server, gives no errors. But when ran using rthe above method in java, gives errors as follows,
Mycode:
String command = "/bin/sh /tmp/pub/alka/test.sh /tmp/pub/alka/abc/xyz/ul ul";
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(command);
int exitVal = proc.exitValue();
System.out.println("Process exitValue: " + exitVal);
java.io.IOException: CreateProcess: /bin/sh /tmp/pub/alka/test.sh /tmp/pub/alka/abc/xyz/ul ul error=3
     at java.lang.ProcessImpl.create(Native Method)
     at java.lang.ProcessImpl.<init>(Unknown Source)
     at java.lang.ProcessImpl.start(Unknown Source)
     at java.lang.ProcessBuilder.start(Unknown Source)
     at java.lang.Runtime.exec(Unknown Source)
     at java.lang.Runtime.exec(Unknown Source)
     at java.lang.Runtime.exec(Unknown Source)
     at DecryptTest.main(DecryptTest.java:18)
Can anyone please help

Error while Executing Unix Shell Commands Using Runtime clas

I am trying to run the following code in java on unix machine to execute cat command.
Runtime runtime = Runtime.getRuntime();
          try {
               System.out.println("before catexecute");
               Process process = runtime.exec("cat /export/home/shankerr/local.profile > /export/home/shankerr/local1.txt");
               try {
                    if (process.waitFor() != 0) {
                    System.err.println("exit value = " +
                              process.exitValue());
                    catch (InterruptedException e) {
                    System.err.println(e);
But i get the following error on the console
exit value = 2
cat: cannot open >
cat: cannot open /export/home/shankerr/local1.txt
The same command if i run on unix console directly it creates a new file and copies the content into the new file local1.txt
kindly help me on the same

The redirection operator > along with stuff like pipe | history !$ etc. is interpreted by the shell, not by the cat program.
When you do cat X > Ycat only sees the X. The rest is interpreted by the shell to redirect the cat program's stdout.
However, when you Runtime.exec(), you don't have the shell, so cat sees X > Y as its arguments, and interprets them all as file names. Since there's no file named > you get the error.
The solution is to first man cat on your system and see if it happens to have a -o or somesuch operator that lets it (rather than the shell) send its output to a file. If not, then you need to invoke a shell, and pass it cat and all of cat's args as the command to execute.
Read the man pages for you shell of choice, but for bash, I believe you'd give Runtime.exec() something like /bin/bash -c 'cat X > Y'

Process.exitValue() ??

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