Method 1: Filter by Process ID (PID) - Recommended#

This is the most precise method as logs are directly associated with the application’s running process.

1. Get your app’s PID:

   First, find the Process ID (PID) of your running application. Open a new command line window and type:

   Bash

   adb shell pidof -s your.package.name
   

   Replace your.package.name with your app’s actual package name (e.g., com.example.myapp). This command will return the app’s PID, for instance, 12345.

2. Filter using PID and Error Level:

   Once you have the PID, run the logcat command in another command line window, combining the —pid argument with thelevel filter:

   Bash

   adb logcat --pid=12345 *:E
   

   Or, more concisely, you can nest the pidof command:

   Bash

   adb logcat --pid=$(adb shell pidof -s your.package.name) *:E
   

   (Note: In some shells, you might need to use backticks instead of $(...), e.g., adb logcat --pid=\adb shell pidof -s your.package.name*:E)

   • --pid=12345: Displays logs only from the process with PID 12345.
   • *:E: Shows logs of Error (E) level or higher (Fatal, Assert) from all tags.

Method 2: Filter by Log Tag and Error Level#

If your application consistently uses a specific tag when printing logs, you can filter by that tag.

1. Identify your app’s log tag:

   In your app’s code, the TAG in Log.e(TAG, ”…”) is what you’ll use for filtering. For example:

   Java

   // Java
   private static final String TAG = "MyAppError";
   Log.e(TAG, "Something went wrong!");
   

   Kotlin

   // Kotlin
   const val TAG = "MyAppError"
   Log.e(TAG, "Something went wrong!")
   

2. Filter using the tag and error level:

   Bash

   adb logcat YourAppTag:E *:S
   

   • YourAppTag:E: Displays logs only with the tag YourAppTag and of Error (E) level or higher.
   • *:S: This is crucial. It means “Silence all other tags.” Without this, logcat would still display error logs from other processes. Adding *:S ensures that only the error logs for your specified YourAppTag are shown.

Method 3: Filter by Package Name using grep (Less Accurate)#

This method pipes the logcat output through the grep command to perform text matching. While generally useful, it might not catch all relevant logs, as some system errors related to your app might not explicitly contain your package name in the log message.

1. Know your app’s package name:

   For example: com.example.myapp

2. Filter using grep:

   Bash

   adb logcat *:E | grep "com.example.myapp"
   

   • *:E: First, logcat outputs only error-level logs.
   • | grep "com.example.myapp": Then, grep further filters these error logs to show only lines that contain your application’s package name.

Which Method Is Best?#

• Method 1 (PID filtering): This is the most recommended and accurate approach. It directly targets your app’s process, effectively excluding irrelevant logs from other processes.
• Method 2 (Tag filtering): If your app has a well-managed and consistent logging tag strategy, this method is very effective. The use of *:S is key here.
• Method 3 (Grep filtering): This is simple and often good enough for quick checks, but it’s less precise because it relies on text matching and might miss some relevant logs that don’t explicitly contain the package name.

Choose the method that best suits your current needs for debugging and logging analysis.