How to dump Android logcat withtout ADB?

Question

I know that I can use adb to dump logcat to a file, but I am having issues configuring the drivers for my device (Moverio BT-200). Therefore, adb can't find the device, and then it can't retrieve the logcat.

My application is crashing at start, so I cannot retrieve the logcat programmatically. I tested my app on some other devices (with Android 5.1 and 4.4.2), and it's working fine, so I think it's a problem with the old Android version (4.0.3); yet Android Studio is not giving me any warning about the API version.

Is there some other way to dump the logcat output?

try to solve the real issues you have (getting `adb` drivers to work) instead of creating new ones — Alex P., Apr 07 '15 at 17:28
I am already trying to fix that, and I have already opened another thread with Epson support for that. I asked this because I am looking for workarounds. Anyway, why the downvote? — ocramot, Apr 08 '15 at 08:01

score 0 · Answer 1 · answered Apr 07 '15 at 16:42

You can dump your logcat programmically:

Runtime.getRuntime().exec("logcat -v time -f /sdcard/mylog.log -d");

I like to use this in conjunction with Thread.setDefaultUncaughtExceptionHandler which catches all uncaught exceptions into a callback. In the callback I dump the log and then throw the exception again to let the app crash.

score 0 · Accepted Answer · edited May 23 '17 at 12:28

Thanks to Randy's suggestion, I used a similar old code of mine to log the exception to a file (I tried to use the runtime exec, but it only produced an empty file).

Here is the code I used:

Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
    public void uncaughtException(Thread t, Throwable e) {
        File logFile = new File("/any/directory/logFile.log");
        PrintWriter out = null;

        try{
            if(!logFile.exists()){
                try {
                    if(!logFile.createNewFile())
                        Log.e(TAG, "Some error creating log file " + logFile.getAbsolutePath());
                } catch (IOException ex) {
                    Log.e(TAG, "IoException creating logFile: " + ex.getMessage());
                    ex.printStackTrace();
                }               
            }

            out = new PrintWriter(new BufferedWriter(new FileWriter(logFile, true)));
            out.println(
                new SimpleDateFormat("yyyy-MM-dd_hh:mm:ss.SSS", Locale.getDefault()).format(new Date()) + "\t" +
                TAG + "\t" +
                "Thread " + t + " throws exception: " + e
            );
            if(e != null)
                e.printStackTrace(out);
            out.flush();
        } catch (IOException ex) {
            Log.e(TAG, "IoException writing logFile: " + ex.getMessage());
            ex.printStackTrace();
        } finally {
            if(out != null)
                out.close();
        }
    });
}

How to dump Android logcat withtout ADB?

2 Answers2