title: How I start a process to run logcat on Android?
body: <p>I want to read Android system level log file.So I use the following code:</p>
  
  <pre><code>        Process mLogcatProc = null;
      BufferedReader reader = null;
      try {
          mLogcatProc = Runtime.getRuntime().exec(
                  new String[] { "logcat", "-d",
                          "AndroidRuntime:E [Your Log Tag Here]:V *:S" });
  
          reader = new BufferedReader(new InputStreamReader(mLogcatProc
                  .getInputStream()));
  
          String line;
          final StringBuilder log = new StringBuilder();
          String separator = System.getProperty("line.separator");
  
          while ((line = reader.readLine()) != null) {
              log.append(line);
              log.append(separator);
          }
  
      }
  
      catch (IOException e) {}
      finally {
          if (reader != null)
              try {
                  reader.close();
              } catch (IOException e) {}
  
      }
  </code></pre>
  
  <p>I also used  in AndroidManifest.xml.
  But I can't read any line. The StringBuilder log is empty. And the method mLogcatProc.waitFor return 0.</p>
  
  <p>So how can I read the log ?</p>