重定向标准输出中的Andr​​oid NDK到logcat的 [英] Redirect stdout to logcat in Android NDK

问题描述

我不能让我的Nexus S（运行Android 4.0）重定向本地标准输出消息logcat的。我读过，我需要做到这一点：

I can't get my Nexus S (running Android 4.0) to redirect native stdout message to logcat. I've read that I need to do this:

$ adb shell stop
$ adb shell setprop log.redirect-stdio true
$ adb shell start

不过，这似乎并没有工作。 （它确实打破的JUnit不过，正如<一个href="http://stackoverflow.com/questions/3462850/trying-to-run-trivial-android-junit-tests-getting-test-run-failed-no-test-re">here,所以它不是没有效果。）

However, this doesn't seem to work. (It does break JUnit though, as mentioned here, so it's not without effect.)

有关参考，这里是我的code：

For reference, here's my code:

package com.mayastudios;

import android.util.Log;

public class JniTester {

  public static void test() {
    Log.e("---------", "Start of test");
    System.err.println("This message comes from Java.");    
    void printCMessage();
    Log.e("---------", "End of test");
  }

  private static native int printCMessage();

  static {
    System.loadLibrary("jni_test");
  }
}

和JNI的.c文件：

JNIEXPORT void JNICALL
Java_com_mayastudios_JniTester_printCMessage(JNIEnv *env, jclass cls) {
  setvbuf(stdout, NULL, _IONBF, 0);
  printf("This message comes from C (JNI).\n");
  fflush(stdout);

  //setvbuf(stderr, NULL, _IONBF, 0);
  //fprintf(stderr, "This message comes from C (JNI).\n");
  //fflush(stderr);
}

而Android.mk：

And the Android.mk:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE    := jni_test
LOCAL_SRC_FILES := test_jni.c
include $(BUILD_SHARED_LIBRARY)

我只是通过调用 NDK建造编译这一点。本机方法被正确调用，但我没有得到任何日志输出它（即使在详细）。我得到从Java输出日志，但（此消息来自Java的。）。

I'm compiling this just by calling ndk-build. The native method is called correctly but I don't get any log output from it (even on verbose). I do get the log output from Java though ("This message comes from Java.").

什么，我可能是做错了任何提示？

Any hints of what I might be doing wrong?

PS：我已经设置了一个小Mercurial库演示该问题：<一href="https://bitbucket.org/skrysmanski/android-ndk-log-output/">https://bitbucket.org/skrysmanski/android-ndk-log-output/

PS: I've set up a small Mercurial repository that demonstrates the problem: https://bitbucket.org/skrysmanski/android-ndk-log-output/

推荐答案

这不是明显，我从previous答案。即使在root权限的设备，你需要运行：

This was not obvious to me from the previous answers. Even on rooted devices you need to run:

adb root
adb shell stop
adb shell setprop log.redirect-stdio true
adb shell start

这篇关于重定向标准输出中的Andr​​oid NDK到logcat的的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！