How to know a process of an app is 32-bit or 64-bit programmatically in Android lollipop?

Question

As we all know from Android 5.0.64bit support is there. I have very simple question. Can we check programmatically in what mode any application is running i.e. 32bit or 64bit? For example: I have Facebook app running on my Nexus 9, so can I check using my android app if Facebook app's process is running in 32bit mode or 64bit mode?

Answer 1

In Nexus 5x

String arch = System.getProperty("os.arch");

returns

armv8l

it is not aarch64 and my code broke. However,

root@bullhead:/ # uname -m
aarch64

root@bullhead:/ # getprop ro.product.cpu.abilist
arm64-v8a,armeabi-v7a,armeabi

Wired. So I changed my code to

boolean is64 = (android.os.Build.VERSION.SDK_INT >= 21) && System.getProperty("ro.product.cpu.abilist").contains("64");

Updated on 2016-02-11

In Samsung Samsung Galaxy S5 Neo, Android 5.1.1

String arch = System.getProperty("os.arch");

returns aarch64 but it is not 64-bit device!!!

ro.product.cpu.abilist returns armeabi-v7a,armeabi

bool is64Bit =   System.getProperty("ro.product.cpu.abilist").contains("64");

check is the only way to check.