Develop Reference

Whitelist my App in logcat / chatty identical 1 line

Logcat is filtering my logs, so I get only:
1234-1234/com.example.test I/chatty: uid=45678(com.example.test) identical 1 line
This is a serious issue for me, I tried applying the solutions suggested in other threads like
adb logcat -P ""
I also read the documentation (logcat --help and the "-P" option at official documentation like adb logcat -P 45678), but this also didn't help.
adb logcat -p shows that I whitelisted my app:
adb logcat -p
45678 (the UID of my app)
Still the logs are getting filtered. How can I fix that? I simply want no log filtering on my app during development.

My fault. I checked in Android Studio where I had the log leve filter set to "Info". The chatty message is "info" level, my log messages were "verbose" level. Actually I am getting both, my app log messages and the chatty messages...
Make sure to test without Android Studio using logcat: adb logcat and see if you see your log message. If that works, something is selected wrong in Android Studio like it was for me and by me.

Filter logs of given application in cmd not working

Note:
This question is a duplicate of Filter log messages by PID or application package in Android.
But there is no correct answer to that question & it is very very old.
I can't make any changes in the app codebase as suggested in the accepted answer, I can only access the app build.
As per Android Docs: https://developer.android.com/studio/command-line/logcat#alternativeBuffers
We should be able to filter logs of a given application using the command:
adb logcat --pid=<pid>
--pid= ... Only print logs from the given PID.
But I am getting an error "unrecognized option" when I enter it in cmd.
Got PID of application using:
adb shell ps <app-package-name>
Note: Want a solution without using cmd alone, not using Android Studio.

For adb --pid command to work , the device/emulator in which you have tired capturing the logcat messages should atleast be Android 7.0 . Otherwise this command will not work.
if you have device with android 7.0 above , then try this command
adb logcat --pid=19816 *:D
replace your pid value and * means (any tag) : D meas DEBUG severity log messages
if you have device which is older versions , you can search specific logcat messages based on your package name string or given tag strings like this
adb logcat | findstr <PACKAGENAME OR TAGS>

How to check Android Log in Window's Terminal?

I am working in an Android Project. I want to see Logs in Window terminal rather than in Android's Logcat.Any suggestion?. I put Logger in my project for example:
Log.d("ufo","Plane inventory Listener is called");
I also want to see Logs of "ufo" in window's terminal?

You need to read logcat documentation for details.
You can see log messages into terminal using below command
To see all logs
adb logcat
Filter logs (like you want to see logs for ufo)
adb logcat | grep "ufo"

To get complete logs of 2 devices using adb

I am testing an app with 2 devices communicating using sockets and monitoring the timestamp values. I select the required device name from the DDMS perspective. But some initial logs are missing(as I have many Log.d statements in the code). I want to store the whole log file after I stop apps in both the phones. Can someone tell me how this can be done in command line using adb? I couldn't find any example for 2 devices.
Thanks

You can try with two console and get logcat separately for two devices
Get serial no for each devices using adb devices
and save logcat as text files
console 1: adb -s <device1serialNO> logcat -d > logcat1.txt
console 2: adb -s <device2serialNO> logcat -d > logcat2.txt
You can filter result for your given tag if needed

Before launching your application you can start the following command in your terminal:
adb logcat <your_application_log_tag>:V *:S > file.txt
<your_application_log_tag> is a log tag that you use in your application. *:S means that you suppress all log outputs from other components. > file.txt redirects the output of the command to file.txt.
The cause of the problem is that for logging Android has a buffer in RAM and if it becomes full it rewrites the most old entries (FIFO). The command I've provided will store the log on your computer.

Logcat displays nothing when used from Runtime.exec

I'm running the command
logcat -d AndroidRuntime:E *:S
When ran from adb on my computer, it displays all the things it should. When I try to run it from an Android application with
Runtime.getRuntime().exec("logcat -d AndroidRuntime:E *:S");
and print the output, it won't display anything except the headers.
How can I fix this?

First, this has never been supported.
Second, if you are running on Android 4.1 and later, you will only get any log messages that your own app logs, not messages from other apps, as you can no longer hold the READ_LOGS permission in an ordinary SDK app.