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

Eric Schulman picture Eric Schulman · Apr 27, 2009 · Viewed 77.5k times · Source

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.");
    }
}

Answer

John Feminella picture John Feminella · Apr 27, 2009

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.