Android NDK __android_log_print function and LogCat

Issue

I have a function like

__android_log_print(ANDROID_LOG_INFO, "HelloNDK!");

on my C code

I wouldn't find that output on my LogCat. What kind of filter I need to setup

by Log Tag, by Log Message, by Application Name, by Log Level...etc.

Solution

You don't find output because you have misused the function. The function has the prototype:

int __android_log_print(int prio, const char *tag,  const char *fmt, ...);

So you must supply a "tag" as well as the format.

For example

__android_log_print(ANDROID_LOG_INFO, "MyTag", "The value is %d", some_variable);

Once you use the function properly, you can use any filtering method (or none at all - such as you'd get from the adb logcat command without further arguments) just as with java code.

Answered By - Chris Stratton