Question

For my server coded in java I want to add a console. I connect to my server using a socket.
Here is the code I’ve made for the console:

On my server:

public class ServerConsole
{   
    public String exec(String[] cmd)
    {
        try
        {
            Process child = Runtime.getRuntime().exec(cmd);

            InputStream in = child.getInputStream();
            StringBuffer buffer = new StringBuffer();
            int c;
            while ((c = in.read()) != -1)
            {
                buffer.append((char)c);
            }
            in.close();

            return buffer.toString();
        }
        catch (Exception e) {}

        return "FAILED";
    }
}

This class execute the given command and returns a string that contains the content of the console after execution.

I call this method like that:

String cmd_data_cmd = inputStream.readUTF();
String[] dataCmd = cmd_data_cmd.split("#");
OSCmd osCmd = new OSCmd();
outputStream.writeUTF(osCmd.exec(dataCmd));

Where inputStream is the stream I use with my socket. It works well!

Now, on the client side, I’ve made that:

String[] cmd = cmd_input.getText().split(" ");
String new_cmd = "";
for (String part : cmd)
    new_cmd += (new_cmd.equals("") ? "": "#") + part;

this.outputSocket.writeUTF(new_cmd);
DataInputStream result_input = new DataInputStream(this.input);
String tmp = result_input.readUTF();
System.out.println(tmp);

This should returns me the result displayed in the console but actually, nothing happens. It just freezes when I start that part of code.

Any idea how to do that?

Thanks.

Answer 1

Here is the solution:

String[] cmd_exec = {};
String os_name = System.getProperty("os.name").toLowerCase();
if (os_name.indexOf("win") >= 0)
    cmd_exec = new String[]{"cmd.exe", "/c", cmd};
else if (os_name.indexOf("mac") >= 0)
    cmd_exec = new String[]{"/usr/bin/open", "-a", cmd};
else if (os_name.indexOf("nix") >= 0 || os_name.indexOf("nux") >= 0)
    cmd_exec = new String[]{"/bin/bash", cmd};
else if (os_name.indexOf("sunos") >= 0)
    cmd_exec = new String[]{"/bin/bash", cmd};

Process child = Runtime.getRuntime().exec(cmd_exec);

String line;
while ((line = stdInput.readLine()) != null)
{
    buffer.append("\t" + new String(line.getBytes("UTF-8"), "UTF-8") + "\n");
}
stdInput.close();
while ((line = stdError.readLine()) != null)
{
    buffer.append("\t" + new String(line.getBytes("UTF-8"), "UTF-8") + "\n");
}
stdError.close();

child.destroy();

Hope this will help someone else.