从android执行shell命令

Question

我正在尝试从应用程序模拟器终端执行此命令(您可以在谷歌播放中找到它)在这个应用程序中我写su并按enter,所以写道:

screenrecord --time-limit 10 /sdcard/MyVideo.mp4

然后再次按下enter并使用android kitkat的新功能开始录制屏幕.

所以,我尝试使用以下方法从java执行相同的代码:

Process su = Runtime.getRuntime().exec("su");
Process execute = Runtime.getRuntime().exec("screenrecord --time-limit 10 /sdcard/MyVideo.mp4");

但是不起作用,因为没有创建文件.显然我在安装了android kitkat的root设备上运行.问题出在哪儿？我怎么解决？因为从终端模拟器工作和Java不？

Answer 1

您应该获取su刚刚启动的进程的标准输入并在那里写下命令,否则您将使用当前命令运行命令UID.

尝试这样的事情:

try{
    Process su = Runtime.getRuntime().exec("su");
    DataOutputStream outputStream = new DataOutputStream(su.getOutputStream());

    outputStream.writeBytes("screenrecord --time-limit 10 /sdcard/MyVideo.mp4\n");
    outputStream.flush();

    outputStream.writeBytes("exit\n");
    outputStream.flush();
    su.waitFor();
}catch(IOException e){
    throw new Exception(e);
}catch(InterruptedException e){
    throw new Exception(e);
}

Answer 2

@CarloCannas修改代码:

public static void sudo(String...strings) {
    try{
        Process su = Runtime.getRuntime().exec("su");
        DataOutputStream outputStream = new DataOutputStream(su.getOutputStream());

        for (String s : strings) {
            outputStream.writeBytes(s+"\n");
            outputStream.flush();
        }

        outputStream.writeBytes("exit\n");
        outputStream.flush();
        try {
            su.waitFor();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        outputStream.close();
    }catch(IOException e){
        e.printStackTrace();
    }
}

(欢迎您为outputStream.close()找到更好的地方)

用法示例:

private static void suMkdirs(String path) {
    if (!new File(path).isDirectory()) {
        sudo("mkdir -p "+path);
    }
}

更新: 要获得结果(输出到stdout),请使用:

public static String sudoForResult(String...strings) {
    String res = "";
    DataOutputStream outputStream = null;
    InputStream response = null;
    try{
        Process su = Runtime.getRuntime().exec("su");
        outputStream = new DataOutputStream(su.getOutputStream());
        response = su.getInputStream();

        for (String s : strings) {
            outputStream.writeBytes(s+"\n");
            outputStream.flush();
        }

        outputStream.writeBytes("exit\n");
        outputStream.flush();
        try {
            su.waitFor();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        res = readFully(response);
    } catch (IOException e){
        e.printStackTrace();
    } finally {
        Closer.closeSilently(outputStream, response);
    }
    return res;
}
public static String readFully(InputStream is) throws IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    byte[] buffer = new byte[1024];
    int length = 0;
    while ((length = is.read(buffer)) != -1) {
        baos.write(buffer, 0, length);
    }
    return baos.toString("UTF-8");
}

静默关闭许多Closeables(Soсket可能不可关闭)的实用程序是:

public class Closer {
// closeAll()
public static void closeSilently(Object... xs) {
    // Note: on Android API levels prior to 19 Socket does not implement Closeable
    for (Object x : xs) {
        if (x != null) {
            try {
                Log.d("closing: "+x);
                if (x instanceof Closeable) {
                    ((Closeable)x).close();
                } else if (x instanceof Socket) {
                    ((Socket)x).close();
                } else if (x instanceof DatagramSocket) {
                    ((DatagramSocket)x).close();
                } else {
                    Log.d("cannot close: "+x);
                    throw new RuntimeException("cannot close "+x);
                }
            } catch (Throwable e) {
                Log.x(e);
            }
        }
    }
}
}

Answer 3

Process p;
StringBuffer output = new StringBuffer();
try {
    p = Runtime.getRuntime().exec(params[0]);
    BufferedReader reader = new BufferedReader(
            new InputStreamReader(p.getInputStream()));
    String line = "";
    while ((line = reader.readLine()) != null) {
        output.append(line + "\n");
        p.waitFor();
    }
} 
catch (IOException e) {
    e.printStackTrace();
} catch (InterruptedException e) {
    e.printStackTrace();
}
String response = output.toString();
return response;