Write android logcat data to a file

Question

I want to dump Android logcat in a file whenever user wants to collect logs. Through adb tools we can redirect logs to a file using adb logcat -f filename, but how can I do this programmatically?

Answer 1

Here is an example of reading the logs.

You could change this to write to a file instead of to a TextView.

Need permission in AndroidManifest:

<uses-permission android:name="android.permission.READ_LOGS" /> 

Code:

public class LogTest extends Activity {   @Override   public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.main);     try {       Process process = Runtime.getRuntime().exec("logcat -d");       BufferedReader bufferedReader = new BufferedReader(       new InputStreamReader(process.getInputStream()));        StringBuilder log = new StringBuilder();       String line;       while ((line = bufferedReader.readLine()) != null) {         log.append(line);       }       TextView tv = (TextView) findViewById(R.id.textView1);       tv.setText(log.toString());     } catch (IOException e) {     }   } } 

Answer 2

Logcat can write directly to a file:

public static void saveLogcatToFile(Context context) {         String fileName = "logcat_"+System.currentTimeMillis()+".txt";     File outputFile = new File(context.getExternalCacheDir(),fileName);     @SuppressWarnings("unused")     Process process = Runtime.getRuntime().exec("logcat -f "+outputFile.getAbsolutePath()); } 

more info on logcat: see http://developer.android.com/tools/debugging/debugging-log.html