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.
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.
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).
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) {
}
}
}
also you need
<uses-permission android:name="android.permission.READ_LOGS" />
referenced here
I have created a class for saveing logcat to file, check this:
import android.os.Environment;
import android.util.Log;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
/**
* This singleton class is for debug purposes only. Use it to log your selected classes into file. <br> Needed permissions:
* READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE, READ_LOGS" <br><br>Example usage:<br> <code> FileLogHelper.getInstance().addLogTag(TAG);</code>
* <p/>
* Created by bendaf on 2016-04-28
*/
public class FileLogHelper{
private static final String cmdBegin = "logcat -f ";
private static final boolean shouldLog = true; //TODO: set to false in final version of the app
private static final String TAG = "FileLogHelper";
private String logFileAbsolutePath;
private String cmdEnd = " *:F";
private boolean isLogStarted = false;
private static FileLogHelper mInstance;
private FileLogHelper(){}
public static FileLogHelper getInstance(){
if(mInstance == null){
mInstance = new FileLogHelper();
}
return mInstance;
}
public void initLog(){
if(!isLogStarted && shouldLog){
SimpleDateFormat dF = new SimpleDateFormat("yy-MM-dd_HH_mm''ss", Locale.getDefault());
String fileName = "logcat_" + dF.format(new Date()) + ".txt";
File outputFile = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/logcat/");
if(outputFile.mkdirs() || outputFile.isDirectory()){
logFileAbsolutePath = outputFile.getAbsolutePath() + "/" + fileName;
startLog();
}
}
}
private void startLog(){
if(shouldLog){
try{
File prevLogFile = new File(logFileAbsolutePath);
prevLogFile.delete();
Runtime.getRuntime().exec(cmdBegin + logFileAbsolutePath + cmdEnd);
isLogStarted = true;
}catch(IOException ignored){
Log.e(TAG, "initLogCat: failed");
}
}
}
/**
* Add a new tag to file log.
*
* @param tag The android {@link Log} tag, which should be logged into the file.
* @param priority The priority which should be logged into the file. Can be V, D, I, W, E, F
*
* @see <a href="http://developer.android.com/tools/debugging/debugging-log.html#filteringOutput">Filtering Log Output</a>
*/
public void addLogTag(String tag, String priority){
String newEntry = " " + tag + ":" + priority;
if(!cmdEnd.contains(newEntry)){
cmdEnd = newEntry + cmdEnd;
if(isLogStarted){
startLog();
}else{
initLog();
}
}
}
/**
* Add a new tag to file log with default priority, which is Verbose.
*
* @param tag The android {@link Log} tag, which should be logged into the file.
*/
public void addLogTag(String tag){
addLogTag(tag, "V");
}
}
Call the FileLogHelper.getInstance().addLogTag(<YOUR_TAG>); function in your onCreate() for example and the folder will be placed the default external storage, which is /storage/emulated/0/ on the most of the phones.
Please let me know if you find any bug in the code!
Some phone can't write to external directory. So we have to write to android cache directory
public static void writeLogToFile(Context context) {
String fileName = "logcat.txt";
File file= new File(context.getExternalCacheDir(),fileName);
if(!file.exists())
file.createNewFile();
String command = "logcat -f "+file.getAbsolutePath();
Runtime.getRuntime().exec(command);
}
Above method will write all logs into the file. Also please add below permissions in Manifest file
<uses-permission android:name="android.permission.READ_LOGS" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
public static void printLog()
{
String filename = Environment.getExternalStorageDirectory().getPath() + File.separator + "myandroidapp.log";
String command = "logcat -f "+ filename + " -v time *:V";
try{
Runtime.getRuntime().exec(command);
}
catch(IOException e){
e.printStackTrace();
}
}
