code: public boolean checkSuExists() {
          Process process = null;
          try {
              process = Runtime.getRuntime().exec(new String[] { "which", BINARY_SU });
              BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
              return in.readLine() != null;
          } catch (Throwable t) {
              return false;
          } finally {
              if (process != null) process.destroy();
          }
      }
docs: A variation on the checking for SU, this attempts a 'which su'
  @return true if su found