Sending an intent from c++ to java in Android 5.0.1_r1

After going through several posts I figured out I could send the intent with the following line of code (second line used for debugging):

int ret = system("am broadcast -a android.intent.action.MIKE_ACCESSED --user 0"); 

__android_log_print(ANDROID_LOG_DEBUG, "gxp18", "Shell command returned %i", ret);

Unfortunately, this returns always (No matter what is the command used in the system("...")):

Shell command returned 32512

Interestingly, I can successfully send the intent through adb using:

adb shell am broadcast -a android.intent.action.MIKE_ACCESSED