Learning Android

The Filesystem Explained

So, where does the device store these preferences? How secure is my username and password? To answer that, we need to look at how the Android filesystem is organized.

Exploring the Filesystem

There are two ways for you to access the filesystem on an Android device: via Eclipse or the command line.

In Eclipse, we use the File Explorer view to access the filesystem. To open up the File Explorer view, go to Window→Show View→Other…→Android→File Explorer. You can also access the File Explorer view via the DDMS perspective. Select the DDMS perspective icon in the top-right corner of Eclipse:

or go to Window→Open Perspective→Other…→DDMS. If you have multiple devices connected to your workstation, make sure you select which one you are working with in the Devices view. You should now be able to navigate through the device’s filesystem.

If you prefer the command line, you can always use adb shell to get to the shell of the device. From there you can explore the filesystem like you would on any other Unix platform.

Filesystem Partitions

There are three main parts of the filesystem on every Android device. As shown in Figure 7-5, they are:

• The system partition (/system/)

• The SDCard partition (/sdcard/)

• The user data partition at (/data/)

Figure 7-5. The filesystem as seen via File ...