Develop Reference

Identify read logs from log buffer in Android programmatically

I have a program to read logs and based on certain filters save logs to database.
private static final String LOGCAT_EVENTS_CMD = "logcat -b events -v time";
try {
EventProcess = Runtime.getRuntime().exec(LOGCAT_EVENTS_CMD);
BufferedReader eventBufferedReader = new BufferedReader(new InputStreamReader(
EventProcess.getInputStream()));
String line = "";
while ((line = eventBufferedReader.readLine()) != null) {
onLogFetched(line);
}
} catch (Exception e) {
e.printStackTrace();
}
But sometimes android kills my application and my application restarts automatically START_STICKY. In this case already read logs are read again and again saved to database.
I want a piece of code which will restrict/identify already read logs.
For clearing the log buffer in android we have command as:-
adb logcat -c
And also I can't clear log buffer before start of process as it will clear logs which was not recorded.(logs generated between kill of App and start of App/Monitoring log Process)

Android Wear - code to read LogCat output programmatically and continuously is not working

Hi everyone I recently wrote some code to read LogCat output continuously within a background Thread started by a background Service in my app. I do not think there are errors in my code but it's not working.
In my Thread, I have:
#Override
public void run() {
Process process = null;
String cmd = "logcat -v time | grep 'AudioFocus requestAudioFocus()'";
try {
process = Runtime.getRuntime().exec("su");
DataOutputStream os = new DataOutputStream(process.getOutputStream());
os.writeBytes("logcat -c" + "\n");
os.writeBytes(cmd + "\n");
os.flush();
} catch(Exception e) {
}
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line;
try {
while ( (line = reader.readLine()) != null ) {
Log.e(StaticVal.TAG, line);
// code for write line to my own log file
}
} catch(Exception e) {
}
}
I also added permission to manifest:
<uses-permission android:name="android.permission.READ_LOGS" />
However, when I plug my device with PC and test it with Android Studio, Log.e(StaticVal.TAG, line); did not print out the results and nothing wrote into my own log file.
Any help is appreciated!
(Directly run logcat -v time | grep 'AudioFocus requestAudioFocus()' on my device through adb terminal get the results as expected)

How to collect LogCat messages in an Android application

I have an application and I'd like to collect the LogCat messages of a specified level and tag.
Can I somehow get the accumulated messages at some point? I don't want to collect the messages one by one, it should be the sum of them like when I use adb to read the actual log. Is this possible?

Try this: Note that in Android 4 you will only see the log messages that were written by your own app unless you have root access.
public static String getLog(Context c) {
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);
log.append("\n");
}
return log.toString();
} catch (IOException e) {
return null;
}
}

Why not just write them to a file instead? LogCat is really for real-time logs. There are lots of good quality logging packages that can log to a file if that's what you want to do.
Just as an example:
How to write logs in text file when using java.util.logging.Logger

command line from within a program - not all commands are executed issue

I wrote some code that runs an android command line and collect the output.
it is executing "ls" correctly but when I put the command "top -n 1" it shows nothing.
is it a manifest issue? the phone is not rooted and when using "terminal emulator" I can see "top" output.
here is the code:
// ** execute command line and gather the output **//
final StringBuilder log = new StringBuilder();
try{
ArrayList<String> commandLine = new ArrayList<String>();
commandLine.add("top");
commandLine.add("-n1");
Process process = Runtime.getRuntime().exec(commandLine.toArray(new String[0]));
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line;
while ((line = bufferedReader.readLine()) != null){
log.append(line);
log.append(", \n");
}
log.append(", \n");
}
catch (IOException e){
}
thanks,
A.

You might want to show some of your code. Generally, commands you run using Runtime are not executed in a shell, so you might want to try something like "sh -c top -n 1" as the prog parameter.

Reading Logcat within the app returns null

I read the other posts and can't figure out the "trick".
I looked at Log Collector but can't use a separate APK. I'm basically using the same approach and I consistently get nothing back on the processes inputstream.
I have READ_LOGS in the manifest.
From within my default activity, I'm able to get the log, but if I move the logic to another activity or utilize an asynctask, no output is returned.
this code is from my default activity... inline, i dump it to the log
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);
}
Log.d(LOGTAG, "Logcat: " +log.toString());
} catch (IOException e) {}
if i wrap it in an asynctask or just inline it in another activity, it returns nothing
ArrayList<String> commandLine = new ArrayList<String>();
//terminate on completion and suppress everything except the filter
commandLine.add("logcat -d -s");
...
//replace asynctask with inline (could not get log in asynctask)
showProgressDialog(getString(R.string.acquiring_log_progress_dialog_message));
final StringBuilder log = new StringBuilder();
BufferedReader bufferedReader = null;
try{
Process process = Runtime.getRuntime().exec(commandLine.toArray(new String[0]));
bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line;
while ((line = bufferedReader.readLine()) != null){
log.append(line);
log.append(MangoApp.LINE_SEPARATOR);
}
sendIntent.putExtra(Intent.EXTRA_TEXT, log.toString());
startActivity(Intent.createChooser(sendIntent, getString(R.string.chooser_title)));
dismissProgressDialog();
dismissMainDialog();
finish();
}
catch (IOException e){
dismissProgressDialog();
showErrorDialog(getString(R.string.failed_to_get_log_message));
Log.e(LOGTAG, "Log collection failed: ", e);//$NON-NLS-1$
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException ignore) {}
}
}
Can anyone spot the diff or explain the magic? I'm pretty sure the commandline is right in the second version so scratching my head. I'm using 2.1 SDK 7 on the emulator.
Thanks

Hope this will be helpful, you don't have to create file by your self just execute the below command, to get the error info.
Runtime.getRuntime().exec("logcat -v time -r 100 -f /sdcard/log.txt *:E");
Logcat parameters options:
-r <size in kilobytes> -> for specifying the size of file
-f <filename> -> file to which you want to write the logs.

Can you try it without the ArrayList. Just pass the command String
I have implemented it in the following way (without the ArrayList). It works for me.
String baseCommand = "logcat -v time";
baseCommand += " MyApp:I "; // Info for my app
baseCommand += " *:S "; // Silence others
ServicesController.logReaderProcess = Runtime.getRuntime().exec(baseCommand);