Runtime.exec() on RedHat Linux

Question

Guys
Like many before me, it seems, I've having a nightmare with Runtime.exec() across platforms when executing local files.
I've gone for the basic but robust strategy of writing the required function to a local file and then executing the file. This has worked fine on Windows NT/2000 and on Solaris. But RedHat Linux doesn't want to know.
I know my permissions are good to execute. I can create the file then run it at the command line, but then whenever I go to run from within Java I get an exit value of 255.
An old chestnut, I know. But can anyone offer an help?
Cheers
Dom

Answer 1

Here's a small class & main method that illustrates the problem.
The output I get is:
File path: /tmp/Temp26345.sh
chmod +x exit value: 0
Executing file: 255
I can then go into /tmp and run ./Temp26345.sh at the command line and get the "ls" command to run.
import java.io.*;
public class FileExecutor
     public static void main( String[] args )
          if( args.length == 0 )
               System.out.println("Arguments must be given: [filename] [writeable]");
               return;
          try
               FileExecutor fe = new FileExecutor();
               File executable = fe.createFile( args[0] , args[1] );
               fe.executeFile( executable );
          catch( Throwable t )
               t.printStackTrace();
     public File createFile( String fileName , String contents )
          throws IOException
          //Create the file.
          File tempFile = File.createTempFile( fileName , ".sh" );
          //Write to the file.
          FileOutputStream fos = new FileOutputStream( tempFile );
          OutputStreamWriter osw = new OutputStreamWriter( fos, "UTF-8" );
          int length = contents.length();
          osw.write( contents , 0 , length );
          osw.flush();
          osw.close();
          fos.close();
          return tempFile;
     public void executeFile( File file )
          throws InterruptedException , IOException
          String filePath = file.getAbsolutePath();
          System.out.println( "File path: " + filePath );
          Runtime runtime = Runtime.getRuntime();
          //Actual system permission.     
          Process process_perm = runtime.exec( "chmod +x " + filePath );
          int exitValue = process_perm.waitFor();
          System.out.println( "chmod +x exit value: " + exitValue );
          //Execute the file.
          Process process_exec = runtime.exec( filePath );
          exitValue = process_exec.waitFor();
          System.out.println( "Executing file: " + exitValue );