How to write only application logs to an external file in android

Question

I am trying to write the logs of my application to an external file. My logs are like Log.e("Offset",""+mOffset); I am using the following code :

public String writeLogToFile()
{
    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);
                }
            bufferedReader.close();
            return log.toString();
        } 
    catch (IOException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return null;
        }
}

It prints all the logs with system level also. Yes I am putting -d so it is printing but if I put -e or -i it does not write the the file. I just want to write the Log.e("Offset",""+mOffset). Where am I doing wrong?

Should it be like this Runtime.getRuntime().exec("logcat Log.VERBOSE"); and if yes then my logs must be at which level? — Shane, Nov 21 '12 at 12:49
Runtime.getRuntime().exec("logcat -v time"); might like this or Runtime.getRuntime().exec("logcat -v"); — Rahul Baradia, Nov 21 '12 at 12:57
try this link code https://github.com/androidnerds/logger/blob/master/src/com/michaelrnovak/util/logger/service/LogProcessor.java might get help to u.. n try again with caps "V" i.e. Runtime.getRuntime().exec("logcat -V"); — Rahul Baradia, Nov 21 '12 at 13:03
Should i put Log.v("msg","msg"); or Log.e("msg","msg"); is fine — Shane, Nov 21 '12 at 13:21
Please fallow below link, i hope it will helps you. http://stackoverflow.com/questions/2018263/android-logging/28168185#28168185 — Murali Mohan, Jan 27 '15 at 10:29

score 1 · Answer 1 · answered Jan 01 '13 at 16:51

Here is how one can read the logs of the current application. To filter logs I obtain process ID (pid) and compare it with every line of logcat output.

In arguments to logcat I specified to read the last 200 lines and display logs with time.

public String writeLogToFile() {
    StringBuilder logs = new StringBuilder();
    int pid = android.os.Process.myPid();
    String pidPattern = String.format("%d):", pid);
    try {
        Process process = new ProcessBuilder()
                .command("logcat", "-t", "200", "-v", "time")
                .redirectErrorStream(true)
                .start();

        InputStream in = null;

        try {
            in = process.getInputStream();

            BufferedReader reader = new BufferedReader(new InputStreamReader(in));

            String line;
            while ((line = reader.readLine()) != null) {
                if (line.contains(pidPattern)) {
                    logs.append(line).append("\n");
                }
            }
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    Log.e(TAG, "Cannot close input stream", e);
                }
            }
        }
    } catch (IOException e) {
        Log.e(TAG, "Cannot read logs", e);
    }

    return log.toString();
}

How to write only application logs to an external file in android

1 Answers1