title: rm -rf doesnt work with home tilde in java runtime
body: <p>This is my code to delete a folder , this below code wont delete the Downloads directory under home folder.</p>
  
  <pre><code>import java.io.IOException;
  public class tester1{   
          public static void main(String[] args) throws IOException {
          System.out.println("here going to delete stuff..!!");
          Runtime.getRuntime().exec("rm -rf ~/Downloads/2");
          //deleteFile();
          System.out.println("Deleted ..!!");     }    
  }
  </code></pre>
  
  <p>However if I give the complete home path, this works :</p>
  
  <pre><code>   import java.io.IOException;
      public class tester1{   
              public static void main(String[] args) throws IOException {
              System.out.println("here going to delete stuff..!!");
              Runtime.getRuntime().exec("rm -rf /home/rah/Downloads/2");
              //deleteFile();
              System.out.println("Deleted ..!!");
          }
          }
  </code></pre>
  
  <p>Can anybody tell me what am I doing wrong.?</p>