Hello my lovely readers and GlamourROM fans.
I’ve run into so many questions from people regarding how to logcat. So I decided to write a guide for all of you which talks about 3 different ways and I’m sharing here only my preferences. Of course there are more methods, but at the moment I’m sticking with these.
Logcat methods:
- Catlog (Android App)
- Minimal ADB
- Android Monitor(GUI)
Choose one and lets continue.
Catlog
First of all you will need root if you choose this method, because it will give superuser rights to Android logcat app. Magisk rooting method is highly preferred. App I’m using in this tutorial is CatLog. Click here to download it.
App description:
Debug your apps. Find error stacktraces. See what your phone is saying about you behind your back. It’s all there in the system log, aka logcat!
Minimal ADB
Prerequisites:
- Your device is plugged into your computer
- You have USB Debugging enabled under Developer Options (Note: This may be listed as ADB Debugging on some ROM’s)
- You have installed the necessary drivers and your computer is recognizing your device
Head over to AndroidFileHost site. Download installer from there. By default it will install to C:\Program Files (x86)\Minimal ADB and Fastboot. It is preferred to make shortcut. After install open the command line app. Test if your device can be found at all. I type “adb devices” and outcome will be like this:
PS C:\WINDOWS\system32> adb devices
List of devices attached
ad0117020d208b226b device
Which says that device is perfectly recognized and you can proceed with it. You might drive into opposite response from terminal called device unauthorized. In that case you must revoke USB debugging on phone. Here is already written guide for that.
Priority lists:
- V — Verbose (lowest priority)
- D — Debug
- I — Info
- W — Warning
- E — Error
- F — Fatal
- S — Silent (highest priority, on which nothing is ever printed)
You want to set it as error and above to filter unneeded ballast. Command will be like that:
adb logcat *:E >> %userprofile%\Desktop\log.txt
If you want to stop the logging press Ctrl + C or simply unplug your phone.
You will find log.txt transferred in your Desktop.
Android Device Monitor
My preferred method. Tool is deprecated but works really well. This zip is packed from android sdk folder.
Download this:
Extract it and start the tool by clicking on monitor.exe.
Really great GUI solution, all interactive and so on.
Filtering FC log simply write tag:AndroidRuntime to bar for example.
Analyzing logs:
Example of system crashing error:
E/AndroidRuntime: !@*** FATAL EXCEPTION IN SYSTEM PROCESS: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.settings/com.android.settings.Settings}: java.lang.NullPointerException
…
Caused by: java.lang.NullPointerException
at com.android.settings.Settings.updateHeaderList(Settings.java:594)
at com.android.settings.Settings.onBuildHeaders(Settings.java:530)
…
For example in this above error this means that somewhere in your code something is set to null and you are trying to use it as though it isn’t.
The next few lines tell you where in your code you can find the error. I’ve removed all the unnecessary lines from the stacktrace. Stacktrace says that method named updateHeaderList returns a null value. Problem here is a mismatching ID and resource call happens at line 530.
List of tags you should seek for:
AndroidRuntime – this is the main reason of continuous FC like SystemUI crash
DEBUG – usually bootloop, caused due to incomplete binary or library
JavaBinder – similar to ART one
Zygote – Most likely happening due to unproper porting
You can send me a error log if it’s Glamour ROM related.
