如何从尚未关闭的进程中读取数据
本文关键字:进程 读取 数据 | 更新日期: 2023-09-27 18:01:25
我正在用c#编写一个简单的程序,允许客户端连接到服务器并在该服务器上运行MS DOS命令。
程序工作得很好,后来我决定我想要cmd.exe进程运行,而客户端连接到服务器,这就是我被困的地方。我想这么做,这样我就能运行像CD这样的命令并更改工作目录,以前这不会有任何效果,因为cmd.exe进程在命令运行后被关闭。
如果进程已经退出,我似乎只能从StandardOutput
和StandardError
流中读取,是否有任何解决方法?
*创建并返回cmd.exe进程*
private Process createDOS()
{
try
{
// Create a ProcessStartInfo class
ProcessStartInfo startInfo = new ProcessStartInfo("cmd","");
// Set up the values
startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
startInfo.UseShellExecute = false;
startInfo.RedirectStandardOutput = true;
startInfo.RedirectStandardError = true;
startInfo.RedirectStandardInput = true;
startInfo.CreateNoWindow = false;
// Create a cmd.exe process
Process process = new Process();
// Apply the start info and run
process.StartInfo = startInfo;
process.Start();
return process;
}
catch (Exception)
{
return null;
}
}
将响应格式化为字符串的方法:
private string findResponse(StreamReader err,StreamReader outp)
{
string output = outp.ReadToEnd();
string error = err.ReadToEnd();
string ret = "";
// Add the output to the return field if the process actually output data
if (output.Length > 0)
{
ret = "OUTPUT : " + output;
}
// Then attempt to add data from the error stream
if (error.Length > 0)
{
// If output was read, add a newline character separating the two fields
if (ret.Length > 0) ret = ret + Environment.NewLine;
ret = ret + "ERROR : " + error;
}
// If there's no output, that means there's no error, which means the execution was silently succesful
if (ret.Length <= 0)
{
ret = "Command execution succesful!";
}
return ret;
}
服务器监听块:
private void run()
{
while (true)
{
Stream stream = null;
StreamReader sr = null;
StreamWriter sw = null;
Socket socket = null;
Process proc = null;
try
{
socket = server.AcceptSocket();
stream = new NetworkStream(socket);
sr = new StreamReader(stream);
sw = new StreamWriter(stream);
String mode = sr.ReadLine();
sw.WriteLine("Serverside link connected");
sw.Flush();
// Create cmd process in WINPROCESS mode
if (mode == "WINPROCESS")
{
proc = createDOS();
}
String line;
while ((line = sr.ReadLine()) != null)
{
if (mode == "WINPROCESS")
{
proc.StandardInput.WriteLine(line);
proc.StandardInput.Flush();
// Response
sw.WriteLine(findResponse(proc.StandardError, proc.StandardOutput));
sw.Flush();
}
else
{
sw.WriteLine(exeDOS(line));
sw.Flush();
}
}
}
catch (Exception ex)
{
// Silence
}
finally
{
if (socket != null) socket.Close();
if (stream != null) stream.Close();
if (sw != null) sw.Close();
if (sr != null) sr.Close();
if (proc != null) proc.Close();
}
}
}
任何帮助将不胜感激,谢谢!
您需要为OutputDataReceived和ErrorDataReceived事件添加处理程序:
process.StartInfo.RedirectStandardOutput = true;
process.OutputDataReceived +=
new DataReceivedEventHandler(process_OutputDataReceived);
process.StartInfo.RedirectStandardError = true;
process.ErrorDataReceived +=
new DataReceivedEventHandler(process_ErrorDataReceived);
if (process.Start())
{
process.BeginOutputReadLine();
process.BeginErrorReadLine();
process.WaitForExit();
}
}
void process_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
Console.WriteLine(e.Data);
}
void process_ErrorDataReceived(object sender, DataReceivedEventArgs e)
{
Console.WriteLine(e.Data);
}