java - Runtime.getRuntime().exec ("ls"没有输出)

Question

ping 和 date 返回输出，但它没有从“ls”或“pwd”返回任何内容。我最终想做的是运行 SSH 命令。知道我下面缺少什么吗？

//Works and shows the output
executeCommand("ping -c 3 " + "google.com");

//Works and shows the output
executeCommand("date");

//Does not work. No output
executeCommand("sudo ls");

//Does not work. No output
executeCommand("ls");


private void executeCommand(String command) {

 StringBuffer output = new StringBuffer();

 Process p;
  try {
    p = Runtime.getRuntime().exec(command);
    p.waitFor();
    BufferedReader reader = 
    new BufferedReader(new InputStreamReader(p.getInputStream()));

    String line = "";           
    while ((line = reader.readLine())!= null) {
       output.append(line + "\n");
    }

 } catch (Exception e) {
    e.printStackTrace();
}

    Log.d("Output", "Output: " + output.toString());


}

Answer 1

我有两个解决方案

第一个解决方案(您需要 Java 7):

...
ProcessBuilder pb = new ProcessBuilder("ls");
pb.redirectOutput(Redirect.INHERIT);
Process p = pb.start();

第二种解决方案:

    Process p=Runtime.getRuntime().exec("ls");

    InputStream is = p.getInputStream();
    int c;
    StringBuilder commandResponse = new StringBuilder();

    while( (c = is.read()) != -1) {
        commandResponse.append((char)c);
    }
    System.out.println(commandResponse);
    is.close();