Catch LogCat programmatically or export it to file?

Question

I want to filter a logcat

String myCommand="logcat -f /sdcard/output.txt"; //no filters, keep writing  
myCommand="logcat -d -f /sdcard/output.txt"; //no filters, just a dump

Working fine for me but not for mytag .

I am also using the code:

String myCommand="logcat myTag *:S"; //the equivalent of logcat -s myTag  
myCommand="logcat -s myTag:D";   
myCommand="logcat -s myTag:E myTag2:D";  
myCommand="logcat myTag:E myTag2:D";  

But it returns empty file.

Answer 1

try {
   File filename = new File(Environment.getExternalStorageDirectory()+"/gphoto4.html"); 
        filename.createNewFile(); 
        String cmd = "logcat -d -f "+filename.getAbsolutePath();
        Runtime.getRuntime().exec(cmd);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

also use

String cmd = "logcat -v time -r 100 -f <filename> [TAG]:I [MyApp]:D *:S";
Runtime.getRuntime().exec(cmd);


-v -> Sets the output format for log messages.
-r -> for specifying the size of file.
-f -> file to which you want to write the logs.
[TAG] -> Tag of your application's log.
[MyApp] -> Your application name.

Answer 2

File filename = new File(Environment.getExternalStorageDirectory()+"/mylog.log"); 
filename.createNewFile(); 
String cmd = "logcat -d -f"+filename.getAbsolutePath();
Runtime.getRuntime().exec(cmd);

it works for me. but for all logcat output not for special tag(mytag).