Thread: Invoke a linux shell command using Process

Hi every body,

I am trying to execute this commad (/usr/bin/rrdtool lastupdate my_rrdfile_path) in java by Runtime.getRuntime.exe().
executing this command in linux shell will return some status of my system. but when I execute it by java, it returns null!
here is some part of my program:

 
                String rrdCmd = "/usr/bin/rrdtool lastupdate " + rrdPath;
                String temp = null;
		String cmdStResult = null;			
		Process p = null;
 
		try {
			p = Runtime.getRuntime().exec(rrdCmd);
			int exitVal = p.waitFor();
			System.out.println("exitVal of rrdLastUpdate is : " + exitVal);
 
		     } catch (Exception e) {
 
			System.out.println("Problem in exec()");
			e.printStackTrace();
 
			}//end of try-catch
 
 
 
		try {				
 
				InputStreamReader inStreamReader = new InputStreamReader(p.getInputStream());
				BufferedReader stdInput = new BufferedReader(inStreamReader);
 
				while ((s = stdInput.readLine()) != null) {
					System.out.println(s);					
				}//end of while
 
                      } catch (Exception ex) {
				System.out.println("problem!");
				ex.printStackTrace();
		      }//end of try-catch

I thought this forum is most related to my question!
sorry if my english is poor
any guidance would be appreciated
thanks a lot.

sorry, I did not know these rules. thanks for your mention.
excuse me. because I should solve this problem as quickly as possible and nobody answered me here, I asked it in another forum. but actually I didn't know this isn't right.
every body should forgive me

can I ask my question any forum else by linking to here?
now what can I do, when no answer is available