javaoutput-redirect

How to execute system commands (linux/bsd) using Java


I am attempting to be cheap and execute a local system command (uname -a) in Java. I am looking to grab the output from uname and store it in a String. What is the best way of doing this? Current code:

public class lame {

    public static void main(String args[]) {
        try {
            Process p = Runtime.getRuntime().exec("uname -a");
            p.waitFor();
            BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line=reader.readLine();

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

        }
        catch(IOException e1) {}
        catch(InterruptedException e2) {}

        System.out.println("finished.");
    }
}

Solution

  • Your way isn't far off from what I'd probably do:

    Runtime r = Runtime.getRuntime();
    Process p = r.exec("uname -a");
    p.waitFor();
    BufferedReader b = new BufferedReader(new InputStreamReader(p.getInputStream()));
    String line = "";
    
    while ((line = b.readLine()) != null) {
      System.out.println(line);
    }
    
    b.close();
    

    Handle whichever exceptions you care to, of course.