/*      ProcessRunner.java
*       @author: Charles Bell
*       @version: June 21, 2001
*/

import java.io.*;

/**     Executes the String arguments, displays the commands being executed, and displays 
*       any results.
*/
public class ProcessRunner{

	/** Instantiates a class and runs the commands passed in the aguments.
       */
     public static void main(String[] args){
		ProcessRunner runner = new ProcessRunner();
		String[] command = {"/home/sourabh/testscript"};
          runner.runCommand(command);
     }

	/**     Runs the commands in a process and displays the results.
	*/
	public void runCommand(String[] args){
		int number = args.length;
		try{
			String[] commands;


			if (System.getProperty("os.name").compareToIgnoreCase("windows") > 0){
				commands = new String[number + 2];
				commands[0] = "command.com"; //for Windows 95, 98, ME. etc.
				if (System.getProperty("os.name").compareToIgnoreCase("nt") > 0){
					commands[0] = "cmd.exe"; //for Windows NT
				}
				commands[1] = "/c";
				for (int i = 0; i < number;i++){
					commands[i+2] = args[i];
				}
			}else{
				commands = new String[number];
				for (int i = 0; i < number;i++){
					commands[i] = args[i];
				}
		    } 


			System.out.print("Executing: ");
			for (int i = 0; i< commands.length;i++){
				System.out.print(commands[i] + " ");
			}


			Runtime runtime = Runtime.getRuntime();
               Process process = runtime.exec(commands);
			// 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.
			CheckStream csin = new CheckStream(process.getInputStream());
			CheckStream cserr = new CheckStream(process.getErrorStream());
			csin.start();
			cserr.start();
			System.out.print("Waiting for command process to terminate.");
			int done = process.waitFor();
				process.destroy();
				System.out.println("... Done.");      
		}catch(InterruptedException ie){
			System.out.println("InterruptedException: " + ie.getMessage());
		}catch(IOException ioe){
			System.out.println("IOException: " + ioe.getMessage());
		}
	}


     /**     Inner class for checking the results if any of an InputStream.
      */
     class CheckStream extends Thread{
		BufferedReader br;
          String lineread = "";
		/**     Constructor needs an InputStream to form an anonymous 
             *       InputStreamReader which is used to create a BufferedReader
             *       for reading the stream. 
             */
          CheckStream(InputStream is){
               this.br = new BufferedReader(new InputStreamReader(is));                
          }


		/**     Reads the input stream and displays anything returned.
             */
		public void run(){
			try{
				while ((lineread = br.readLine()) != null){
					System.out.println(lineread);
				}
			}catch(IOException ioe){
				System.out.println("IOException: " + ioe.getMessage());
			}
		}
	}
}