Question

首先，我将介绍我的情况。我需要执行＆＃34; su＆＃34;命令在我的Android应用程序中，它运作良好。然后我需要执行＆＃34; ls＆＃34;命令并读取输出。我是通过从＆＃34; su＆＃34;获取输出流来实现的。处理并将命令写入其中。

这就是问题所在。如何阅读＆＃34; ls＆＃34;的输出？处理？我所拥有的只是＆＃34; su＆＃34;过程对象。从中获取输入流没有任何结果，因为＆＃34; su＆＃34;没有写任何东西。但是＆＃34; ls＆＃34;我不知道如何访问其输出消息。

我搜索了很多网站，但我找不到任何解决方案。也许有人会帮助我:)。

此致

Answer 1

好的，我找到了解决方案。它应该是这样的：

Process p = Runtime.getRuntime().exec(new String[]{"su", "-c", "system/bin/sh"});
DataOutputStream stdin = new DataOutputStream(p.getOutputStream());
//from here all commands are executed with su permissions
stdin.writeBytes("ls /data\n"); // \n executes the command
InputStream stdout = p.getInputStream();
byte[] buffer = new byte[BUFF_LEN];
int read;
String out = new String();
//read method will wait forever if there is nothing in the stream
//so we need to read it in another way than while((read=stdout.read(buffer))>0)
while(true){
    read = stdout.read(buffer);
    out += new String(buffer, 0, read);
    if(read<BUFF_LEN){
        //we have read everything
        break;
    }
}
//do something with the output

希望它会对某人有所帮助

Answer 2

public String ls () {
    Class<?> execClass = Class.forName("android.os.Exec");
    Method createSubprocess = execClass.getMethod("createSubprocess", String.class, String.class, String.class, int[].class);
    int[] pid = new int[1];
    FileDescriptor fd = (FileDescriptor)createSubprocess.invoke(null, "/system/bin/ls", "/", null, pid);

    BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(fd)));
    String output = "";
    try {
        String line;
        while ((line = reader.readLine()) != null) {
            output += line + "\n";
        }
    }
    catch (IOException e) {}
    return output;
}

检查此处提及的代码：

How to run terminal command in Android application?

try {
// Executes the command.
Process process = Runtime.getRuntime().exec("/system/bin/ls /sdcard");

// Reads stdout.
// NOTE: You can write to stdin of the command using
//       process.getOutputStream().
BufferedReader reader = new BufferedReader(
        new InputStreamReader(process.getInputStream()));
int read;
char[] buffer = new char[4096];
StringBuffer output = new StringBuffer();
while ((read = reader.read(buffer)) > 0) {
    output.append(buffer, 0, read);
}
reader.close();

// Waits for the command to finish.
process.waitFor();

return output.toString();
} catch (IOException e) {
throw new RuntimeException(e);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}

<强>参考

this code GScript

Answer 3

我修改了@glodos接受的以下问题的答案：

关闭了流，否则exec进程会在打开的流上永久挂起。如果你在shell中执行ps（即adb shell）在几次执行之后，您将看到几个su进程活。他们需要妥善终止。
添加waitFor()以确保流程终止。
添加了read=-1的处理，现在可以执行空stdout的命令。之前他们在new String(buffer, 0, read)

使用StringBuffer进行更有效的字符串处理。

private String execCommand(String cmd) throws IOException, InterruptedException {
    Process p = Runtime.getRuntime().exec(new String[]{"su", "-c", "system/bin/sh"});
    DataOutputStream stdout = new DataOutputStream(p.getOutputStream());

    stdout.writeBytes(cmd);
    stdout.writeByte('\n');
    stdout.flush();
    stdout.close();

    BufferedReader stdin = new BufferedReader(new InputStreamReader(p.getInputStream()));
    char[] buffer = new char[1024];
    int read;
    StringBuffer out = new StringBuffer();

    while((read = stdin.read(buffer)) > 0) {
        out.append(buffer, 0, read);
    }
    stdin.close();
    p.waitFor();
    return out.toString();
}

有些学分归@Sherif elKhatib））

读取su进程内的命令输出

3 个答案: