Question

是否可以检查调用进程从另一个共享库（.so）加载哪些共享库？我知道有这样的命令行工具，但是可以在C ++代码中执行这样的检查吗？

我需要以某种方式获取Android应用程序加载的本机共享库列表，但似乎无法从Java代码中获取。

Answer 1

您可以使用/proc/<pid>/maps文件或/proc/self/maps作为调用进程：以。。'结尾的行用于链接的共享库。这是一个黑客，但应该工作。请注意，可以多次映射一个库，因此您需要跳过重复。

好消息：你可以用java做到这一点。下面的代码片段将当前进程的共享库打印到logcat。

try {
    Set<String> libs = new HashSet<String>();
    String mapsFile = "/proc/self/maps";
    BufferedReader reader = new BufferedReader(new FileReader(mapsFile));
    String line;
    while ((line = reader.readLine()) != null) {
        if (line.endsWith(".so")) {
            int n = line.lastIndexOf(" ");
            libs.add(line.substring(n + 1));
        }
    }
    Log.d("Ldd", libs.size() + " libraries:");
    for (String lib : libs) {
        Log.d("Ldd", lib);
    }
} catch (FileNotFoundException e) {
    // Do some error handling...
} catch (IOException e) {
    // Do some error handling...
}

我的设备上的输出是：

D/Ldd     (11286): 55 libraries:
D/Ldd     (11286): /system/lib/libc.so
D/Ldd     (11286): /system/lib/libdbus.so
D/Ldd     (11286): /system/lib/librpc.so
D/Ldd     (11286): /system/lib/libEGL.so
D/Ldd     (11286): /system/lib/libstagefright_color_conversion.so
D/Ldd     (11286): /system/lib/libmedia.so
D/Ldd     (11286): /system/lib/libemoji.so
D/Ldd     (11286): /system/lib/libcrypto.so
D/Ldd     (11286): /system/lib/libstagefright_avc_common.so
D/Ldd     (11286): /system/lib/libnativehelper.so
D/Ldd     (11286): /system/lib/libskiagl.so
D/Ldd     (11286): /system/lib/libopencore_player.so
D/Ldd     (11286): /system/lib/libjpeg.so
D/Ldd     (11286): /system/lib/libsurfaceflinger_client.so
D/Ldd     (11286): /system/lib/libstagefright.so
D/Ldd     (11286): /system/lib/libdrm1.so
D/Ldd     (11286): /system/lib/libdvm.so
D/Ldd     (11286): /system/lib/libwebcore.so
D/Ldd     (11286): /system/lib/libGLESv1_CM.so
D/Ldd     (11286): /system/lib/libhardware.so
D/Ldd     (11286): /system/lib/libexif.so
D/Ldd     (11286): /system/lib/libgps.so
D/Ldd     (11286): /system/lib/liblog.so
D/Ldd     (11286): /system/lib/libexpat.so
D/Ldd     (11286): /system/lib/libopencore_common.so
D/Ldd     (11286): /system/lib/libbluedroid.so
D/Ldd     (11286): /system/lib/libm.so
D/Ldd     (11286): /system/lib/libicui18n.so
D/Ldd     (11286): /system/lib/libomx_amrenc_sharedlibrary.so
D/Ldd     (11286): /system/lib/libwpa_client.so
D/Ldd     (11286): /system/lib/libstdc++.so
D/Ldd     (11286): /system/lib/libandroid_runtime.so
D/Ldd     (11286): /system/lib/libz.so
D/Ldd     (11286): /system/lib/libETC1.so
D/Ldd     (11286): /system/lib/libsonivox.so
D/Ldd     (11286): /system/lib/libstlport.so
D/Ldd     (11286): /system/lib/libutils.so
D/Ldd     (11286): /system/lib/libicudata.so
D/Ldd     (11286): /system/lib/libsqlite.so
D/Ldd     (11286): /system/lib/libhardware_legacy.so
D/Ldd     (11286): /system/lib/libpixelflinger.so
D/Ldd     (11286): /system/lib/libvorbisidec.so
D/Ldd     (11286): /system/lib/libstagefright_amrnb_common.so
D/Ldd     (11286): /system/lib/libcutils.so
D/Ldd     (11286): /system/lib/libui.so
D/Ldd     (11286): /system/lib/libmedia_jni.so
D/Ldd     (11286): /system/lib/libomx_sharedlibrary.so
D/Ldd     (11286): /system/lib/libcamera_client.so
D/Ldd     (11286): /system/lib/libskia.so
D/Ldd     (11286): /system/lib/libopencore_net_support.so
D/Ldd     (11286): /system/lib/libnetutils.so
D/Ldd     (11286): /system/lib/libbinder.so
D/Ldd     (11286): /system/lib/libssl.so
D/Ldd     (11286): /system/lib/libicuuc.so
D/Ldd     (11286): /system/lib/libGLESv2.so

如果必要，可以通过android.os.Process.myPid()获得pid。

Answer 2

WRT java，启动一个进程，在有问题的.so上调用ldd。从stdout捕获输出并处理输出：

Process process = Runtime.getRuntime().exec("ldd a.so");  
StreamGobbler outputGobbler = new StreamGobbler(process.getInputStream());  
outputGobbler.start();  
process.waitFor();  
String result = outputGobbler.buffer;

有关课程定义，请参阅StreamGobbler上的开创性帖子。我添加了一个String buffer变量，并在上一个链接的类定义中将此行System.out.println(type + ">" + line);替换为此buffer = buffer + line+"\n";。显然，我还将第二个参数放到了构造函数中。

class StreamGobbler extends Thread
{
    InputStream is;
    String buffer;

    StreamGobbler(InputStream is)
    {
        this.is = is;
        this.buffer = "";
    }

    public void run()
    {
        try
        {
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            String line=null;
            while ( (line = br.readLine()) != null)
                buffer += line+"\n";    
            } catch (IOException ioe)
              {
                ioe.printStackTrace();  
              }
    }
}

检查Linux / Android上另一个共享库中加载的共享库

2 个答案: