// https://codelab.wordpress.com/2014/11/03/how-to-use-standard-output-streams-for-logging-in-android-apps/
#include <jni.h>
#include <pthread.h>
#include <stdio.h>
#include <android/log.h>

static int pfd[2];
static pthread_t thr;

static void *thread_func(void* param)
{
    ssize_t rdsz;
    char buf[128];
    while((rdsz = read(pfd[0], buf, sizeof buf - 1)) > 0) {
        if(buf[rdsz - 1] == '\n') --rdsz;
        buf[rdsz] = 0;  /* add null-terminator */
        __android_log_write(ANDROID_LOG_DEBUG, "StatusNativeLogs", buf);
    }
    return 0;
}

JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved)
{
    /* make stdout line-buffered and stderr unbuffered */
    setvbuf(stdout, 0, _IOLBF, 0);
    setvbuf(stderr, 0, _IONBF, 0);

    /* create the pipe and redirect stdout and stderr */
    pipe(pfd);
    dup2(pfd[1], 1);
    dup2(pfd[1], 2);

    /* spawn the logging thread */
    if(pthread_create(&thr, 0, thread_func, 0) == -1)
        return JNI_VERSION_1_6; // fail silently
    pthread_detach(thr);

    return JNI_VERSION_1_6;
}