How to obtain logs from Android device

One of the required skills of a QA engineer for testing mobile applications is obtaining the error logs or emergency shutdown reports (crash logs). We`ll look through the definition of log and its functions as well as some ways of obtaining the log from the Android devices.

First of all, let's figure it out what are logs.

Logs (or as they are called log files) are files that contain information about the server or computer that record certain actions of the program as well as all user’s activity. They are essential for analyzing  all the processes proceeding at the device.

If we consider the meaning of logs within the QA profession then the main task for a tester is to correctly extract specific logs during the reproduction of  an issue for a much detailed description of the problem. If the tester makes everything right then it will be much easier for the developer to figure out what the problem is and find a solution.

So let’s see how can we obtain logs from an Android device?

 «Minimal ADB» tool

The easiest and fastest way to extract logs is LogCat.

The setup process can be divided into three* parts:

• Device preparation;
• Installing «Minimal ADB» on a PC;
• Logs extracting.

*In the future, the first 2 steps aren’t repeated 

Now let's look at these parts in more detail:

1. Device preparation

The first thing to start is the activation of  the developer mode on a mobile device.

For this we need:

1. Go to device settings;
2. Quickly tap the «About device» button 7 times;

3. Then tap on the «Developer options» button;

4. Activate the «USB debugging» toggler;

The device is now configured to sync with a PC via the Android Debug Bridge.

2. Installing the «Minimal ADB» on PC

Now we need to install «Minimal ADB» on our PC.

This requires:

1. Follow the link Minimal ADB;
2. Download and install the latest  version of «Minimal ADB»;

3 . Logs obtaining

As you have everything needed to obtain the logs, there are just a few simple steps to obtain the text file with logs: 

1. Connect device to PC via USB

(The device will ask for permission to debug from your computer. If you check the «Always allow debugging from this computer» checkbox, you won’t need to repeat this step in the future);

2. Run the «Minimal ADB»;
3. Enter the command adb logcat> D:\myLog.txt (the log file will be saved to the specified path);
4. Reproduce the issue on the device;
5. Press the key combination Ctrl + C on the keyboard (or just remove the USB cable).

That’s it! You did it!  Thesession logs of your  device have been successfully saved to the text file myLog.txt. Now you can attach the log to the bug report.

Log  obtaining via «Android Studio»

There are also other ways to extract logs from Android devices. There are a few ways of obtaining the log with the help of the Android Studio.

Method # 1. Follow these steps:

1. Download «Android Studio» from the archive of the official site (Since the tool you need was removed in the latest versions of the studio, you need to download an older version of «Android Studio», for example 2.3.3. You can find and download previous versions in the archive https://developer.android.com/studio/archive );
2. Install «Android Studio» on your computer (in the future, the first 2 steps won’t be  repeated);
3. Create a new project in «Android Studio» (when creating a new project, you need to correctly indicate the version of the Android device from which you will take logs);

4. Click View -> Tools Windows -> Android Device Monitor («Android Monitor» window opens);

5. Select the Debug option in the drop-down list (it is also advisable to activate the «Scroll to down» mode);

6. Connect the device via USB  (First of all, you need to enable USB debugging on your mobile device as it was described earlier);
7. Reproduce the issue on the device;
8. Remove the USB cable;
9. Select logs and copy them (right-click> Copy or Ctrl + C);
10. Create a .txt file and insert the  logs into it;
11. Save.

Now you have a text file with logs that can be attached to the bug report.

Method #2Follow these steps: 

1. Download and install the latest version of «Android Studio»;
2. Launch «Android Studio»;
3. Connect the device to a PC after enabling the USB debugging;
4. Click on the LogCat tab in Android Studio;

5. Wait till the device load fully;

6. Select an application from the list of running apps;

7. Copy logs (by pressing Ctrl + A and then Ctrl + C);
8. Insert logs into a previously created text document.

The document with logs for attachment is ready.

Method #3. Follow these steps: 

1. Download and install the latest version of «Android Studio»;
2. Run «Android Studio» once to download the necessary files;
3. Connect the device to PC after enabling USB debugging;
4. Go to the Android folder -> sdk -> tools -> lib -> monitor-x86_64;
5. Run the file monitor.exe (you can make a shortcut to the desktop for quick access);
6. Select a device;

7. Select the «LogCat» tab;

8. Wait until the logs are fully loaded;
9. Select all logs (by pressing Ctrl + A);
10. Click the «Save» button;

11. Choose the needed path and save.

Further, it will be enough to run the monitor.exe shortcut without waiting for Android Studio to load.

Logs obtaining is a fairly simple process thought it requires some initial setup and practice.

Logs are very useful at cooperative work of testers and developers as they contain information about the processes on the server or device which is very important for reproducing and fixing defects. Several tools can be used to obtain the logs some of them are given above.