java processbuild CreateProcess error=2 for command "Dir"

[Donald Likens]

What am I missing? My research has told me that the following message means the system can not find the specified command.

Cannot run program "dir": CreateProcess error=2, The system cannot find the file specified

But the system finds the command when I type it in a command prompt.

My Java command follows:

Process process = new ProcessBuilder( args).start();

[Dheeraj Joshi]

May be the path you specified is wrong.

If the exe is in c drive. Then typically, you will write it as

c:\temp.exe

But this need to be written as

c:\\temp.exe

With out the code it is hard to guess. Can you post the code?

Regards
Dheeraj Joshi

[Donald Likens]

My code was not working (same error) so I copied an example from the internet (that looked good to me). Here is the example I copied:

package tests;

import java.io.*;
import java.util.*;

public class DoProcessBuilder {
  public static void main(String args[]) throws IOException {

    if (args.length <= 0) {
      System.err.println("Need command to run");
      System.exit(-1);
    }

    Process process = new ProcessBuilder(args).start();
    InputStream is = process.getInputStream();
    InputStreamReader isr = new InputStreamReader(is);
    BufferedReader br = new BufferedReader(isr);
    String line;

    System.out.printf("Output of running %s is:", 
       Arrays.toString(args));

    while ((line = br.readLine()) != null) {
      System.out.println(line);
    }

  }
 }

The arg pasted is "dir".

[Dheeraj Joshi]

args is an array. You can not pass whole array.
It must be something like

Process process = new ProcessBuilder(args[0]).start();

Can you traverse through args array and figure out in which index the command is present and use it.

Regards
Dheeraj Joshi

[Dheeraj Joshi]

Take a look at the ProcessBuilder class here.

In particular look at the constructors .

Regards
Dheeraj Joshi

[Donald Likens]

Thanks for responding! For clarity I have changed the source as is listed below. No matter what I do I get the same error message:

package tests;

import java.io.*;
import java.util.*;

public class DoProcessBuilder {
  public static void main(String args[]) throws IOException {

    Process process = new ProcessBuilder("dir").start();
    InputStream is = process.getInputStream();
    InputStreamReader isr = new InputStreamReader(is);
    BufferedReader br = new BufferedReader(isr);
    String line;

    System.out.printf("Output of running %s is:", 
       Arrays.toString(args));

    while ((line = br.readLine()) != null) {
      System.out.println(line);
    }

  }
 }

[Dheeraj Joshi]

is "dir" a process?
If you try to execute notepad, i am sure it will execute. Quick execute of following code executed notepad.

String args1 = "notepad";
Process process = null;;
try {
	process = new ProcessBuilder(args1).start();
} catch (IOException e) {
	e.printStackTrace();
}

Similarly you must execute the process which you want.

Regards
Dheeraj Joshi

[Donald Likens]

Your right... Funny the example I copies did a "dir"... What I really want to do is invoke a Java program as a seperate process. If there a way to do this?

[Dheeraj Joshi]

Yes, you can invoke a separate Java process inside another.

Regards
Dheeraj Joshi

[Donald Likens]

Maybe I should start from the beginning... I have a TCP/IP socket server that needs to send information to a Syslog Deamon (UDP Port 514). When this TCP/IP socket server attempts to open the UDP port it gets a bind failure. I was led to believe that a TCP/IP Socket Server could not open a UDP port because they conflict with each other. My planned solution is to write the information to a temporary file and spin off another java program (running in a different process ID) to send the information in the temp file to the SYSLOG Deamon.

Does anyone have a way to do this?

[Donald Likens]

I have figured out how to issue the Java command...

p = new ProcessBuilder( "cmd", CMD).start();

cmd is a process CMD = "Java ... "

Thanks for all your help.

[pavan7678]

I have figured out how to issue the Java command...

p = new ProcessBuilder( "cmd", CMD).start();

cmd is a process CMD = "Java ... "

Thanks for all your help.

what you understand please share with me, i am also trying to do that through java program but i got the error

"start cmd /c": CreateProcess error=2, The system cannot find the file specified

why this error comes what is reason behind it and how to resolve it