Android NDK __android_log_print function and LogCat

Question

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.

Answer 1

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.