Android file system access in C++

Hi. I have some C++ code that is compiled into

libFoo.so

. I am able to load this library on an Android device (Oculus Quest 2) and call functions via

DllImport

.

What I would like to do is pass a

string filePath

path to my shared library. Then I want my C++ code to perform vanilla C++ file operations. For example:

Code (cpp):

1. std::ifstream inFile(filePath);
2. inFile.read(....);
3. inFile.close();

I'm struggling to figure out what

filePath 

needs to be. I think it needs to be something to the effect of:

Code (CSharp):

1. string filePath = Path.Combine("jar:file://" + Application.dataPath + "!/assets/foo/bar/baz.json";

I have verified that my content exists inside `/data/app/com.ham.eggs-gobbledegook==/base.apk/assets/foo/bar/baz.json`. The file is on my device. I just don't know how to open it in C++.

Thanks!

 

Ahhh ok. I think I got it all now. Makes sense.

I assume there's no way to configure Unity to install content to `persistentDataPath` when the `apk` is installed?

 

There is a native AssetManager API included with the NDK for accessing files that are present in application bundles:
https://developer.android.com/ndk/reference/group/asset

This API works for APKs and also for app bundles and install-time Play Asset Delivery pack files.

 

Using

UnityWebInterface

is there a way to get a list of files in a folder?

For example assume I can use it to get the bytes for

StreamingAssets/Foo/Bar/myFile.bin

. Is there a way to get a list of all files in

StreamingAssets/Foo/Bar

so that I can create N requests for each file? On Android still.

Thanks!