Pretty new to C#, I'm trying to create a WinForms Application that will run ScanState and capture the output from it. I've got this code as a test...
private void button1_Click(object sender, EventArgs e)
{
System.Diagnostics.Process process = new System.Diagnostics.Process();
process.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
process.StartInfo.FileName = $"amd64\\scanstate.exe"; ;
process.StartInfo.Arguments = "";
process.StartInfo.UseShellExecute = false;
process.StartInfo.CreateNoWindow = true;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
process.StartInfo.RedirectStandardInput = true;
process.Start();
string q = "";
string err = "";
while (!process.HasExited)
{
q += process.StandardOutput.ReadToEnd();
err += process.StandardError.ReadToEnd();
}
//label1.text = q;
MessageBox.Show(q.ToString());
MessageBox.Show(err);
}
But all I get is two blank message boxes.
Inspecting q shows that apparently it says something.
The inspector says this:
\r\0\n\0s\0t\0r\0a\0t\0o\0r\0 \0p\0r\0i\0v\0i\0l\0e\0g\0e\0s\0 \0a\0r\0e\0 \0r\0e\0q\0u\0i\0r\0e\0d\0 \0t\0o\0 \0r\0u\0n\0 \0t\0h\0i\0s\0 \0t\0o\0o\0l\0.\0\r\0\n\0\r\r\nScanState return code: 34\r\r\n"
I'm not sure what this is or if it can even be converted to plain text.
Hello i'am creating a process in c# that opens a node.js, so far so good but the process seems to end and tipically when i execute the same command from my cmd it stays alive, how can i achieve such thing from c#? Here is the code of the Process
private void buttonStartLLodiAgent_Click(object sender, EventArgs e)
{
//proc.WaitForExit();
ProcessStartInfo psi = new ProcessStartInfo();
psi.CreateNoWindow = true;
psi.RedirectStandardInput = true;
psi.RedirectStandardOutput = true;
psi.UseShellExecute = false;
psi.RedirectStandardError = true;
psi.FileName = "node.exe";
psi.Arguments = AppDomain.CurrentDomain.BaseDirectory + "/LLodiAgent/main.js";
using (var process = Process.Start(psi))
{
//labelStatusLLodiAgent.Text = "Active";
process.BeginOutputReadLine();
process.OutputDataReceived += proc_OutputDataReceived;
//process.WaitForExit();
}
}
public void proc_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
outputConsole.Text = outputConsole.Text + "\r\n" + e.Data;
}
I get my Output right, but it seems like the Node service is not up, so i guess it executes but then kills it.
How to keep the server alive and the c# recieving data?
Thanks in advance, (this is my first post)
I have a crash in Event Viewer with this:
Exception Info: System.ArgumentOutOfRangeException
at System.Text.StringBuilder.ToString()
at XXX.BrainActions+<>c__DisplayClass11_0.<runApp>b__0(System.Object,
System.EventArgs)
The offending code is this, why is StringBuilder causing this exception?
Process process = new Process();
StringBuilder builder = new StringBuilder();
try
{
process.StartInfo.CreateNoWindow = true;
process.StartInfo.UseShellExecute = false;
process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
process.StartInfo.FileName = filename;
process.StartInfo.Arguments = arguments;
process.StartInfo.WorkingDirectory = Themes.getInstance().getScriptPath();
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
process.EnableRaisingEvents = true;
process.Exited += new EventHandler((object sender, System.EventArgs e) => {
string consoleOutput = builder.ToString();
if (!String.IsNullOrWhiteSpace(consoleOutput))
{
Log.INFO("XXX", String.Format("Console output: {0}", builder.ToString()));
}
processesRunning.Remove(process);
if (callbacks != null)
{
callbacks.ActionCompleted(action);
if (processesRunning.Count == 0)
{
callbacks.AllActionsCompleted();
}
}
});
process.Start();
process.PriorityClass = ProcessPriorityClass.High;
process.OutputDataReceived += (sender, args) => builder.Append(args.Data);
process.ErrorDataReceived += (sender, args) => builder.Append(args.Data);
process.BeginOutputReadLine();
process.BeginErrorReadLine();
processesRunning.Add(process);
}
catch (Exception e)
{
}
StringBuilder is used to basically get the output of the external process and log it to the console using Log4net which is basically wrapped in the Log() function. Any ideas? Note that this crash rarely happens I've only seen it once but once is a reason to fix it.
This question already has answers here:
Capturing console output from a .NET application (C#)
(8 answers)
Closed 6 years ago.
I need to spawn a child process that is a console application, and capture its output.
I wrote up the following code for a method:
string retMessage = String.Empty;
ProcessStartInfo startInfo = new ProcessStartInfo();
Process p = new Process();
startInfo.CreateNoWindow = true;
startInfo.RedirectStandardOutput = true;
startInfo.RedirectStandardInput = true;
startInfo.UseShellExecute = false;
startInfo.Arguments = command;
startInfo.FileName = exec;
p.StartInfo = startInfo;
p.Start();
p.OutputDataReceived += new DataReceivedEventHandler
(
delegate(object sender, DataReceivedEventArgs e)
{
using (StreamReader output = p.StandardOutput)
{
retMessage = output.ReadToEnd();
}
}
);
p.WaitForExit();
return retMessage;
However, this does not return anything. I don't believe the OutputDataReceived event is being called back, or the WaitForExit() command may be blocking the thread so it will never callback.
Any advice?
EDIT: Looks like I was trying too hard with the callback. Doing:
return p.StandardOutput.ReadToEnd();
Appears to work fine.
Here's code that I've verified to work. I use it for spawning MSBuild and listening to its output:
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardOutput = true;
process.OutputDataReceived += (sender, args) => Console.WriteLine("received output: {0}", args.Data);
process.Start();
process.BeginOutputReadLine();
I just tried this very thing and the following worked for me:
StringBuilder outputBuilder;
ProcessStartInfo processStartInfo;
Process process;
outputBuilder = new StringBuilder();
processStartInfo = new ProcessStartInfo();
processStartInfo.CreateNoWindow = true;
processStartInfo.RedirectStandardOutput = true;
processStartInfo.RedirectStandardInput = true;
processStartInfo.UseShellExecute = false;
processStartInfo.Arguments = "<insert command line arguments here>";
processStartInfo.FileName = "<insert tool path here>";
process = new Process();
process.StartInfo = processStartInfo;
// enable raising events because Process does not raise events by default
process.EnableRaisingEvents = true;
// attach the event handler for OutputDataReceived before starting the process
process.OutputDataReceived += new DataReceivedEventHandler
(
delegate(object sender, DataReceivedEventArgs e)
{
// append the new data to the data already read-in
outputBuilder.Append(e.Data);
}
);
// start the process
// then begin asynchronously reading the output
// then wait for the process to exit
// then cancel asynchronously reading the output
process.Start();
process.BeginOutputReadLine();
process.WaitForExit();
process.CancelOutputRead();
// use the output
string output = outputBuilder.ToString();
Here's some full and simple code to do this. This worked fine when I used it.
var processStartInfo = new ProcessStartInfo
{
FileName = #"C:\SomeProgram",
Arguments = "Arguments",
RedirectStandardOutput = true,
UseShellExecute = false
};
var process = Process.Start(processStartInfo);
var output = process.StandardOutput.ReadToEnd();
process.WaitForExit();
Note that this only captures standard output; it doesn't capture standard error. If you want both, use this technique for each stream.
I needed to capture both stdout and stderr and have it timeout if the process didn't exit when expected. I came up with this:
Process process = new Process();
StringBuilder outputStringBuilder = new StringBuilder();
try
{
process.StartInfo.FileName = exeFileName;
process.StartInfo.WorkingDirectory = args.ExeDirectory;
process.StartInfo.Arguments = args;
process.StartInfo.RedirectStandardError = true;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
process.StartInfo.CreateNoWindow = true;
process.StartInfo.UseShellExecute = false;
process.EnableRaisingEvents = false;
process.OutputDataReceived += (sender, eventArgs) => outputStringBuilder.AppendLine(eventArgs.Data);
process.ErrorDataReceived += (sender, eventArgs) => outputStringBuilder.AppendLine(eventArgs.Data);
process.Start();
process.BeginOutputReadLine();
process.BeginErrorReadLine();
var processExited = process.WaitForExit(PROCESS_TIMEOUT);
if (processExited == false) // we timed out...
{
process.Kill();
throw new Exception("ERROR: Process took too long to finish");
}
else if (process.ExitCode != 0)
{
var output = outputStringBuilder.ToString();
var prefixMessage = "";
throw new Exception("Process exited with non-zero exit code of: " + process.ExitCode + Environment.NewLine +
"Output from process: " + outputStringBuilder.ToString());
}
}
finally
{
process.Close();
}
I am piping the stdout and stderr into the same string, but you could keep it separate if needed. It uses events, so it should handle them as they come (I believe). I have run this successfully, and will be volume testing it soon.
It looks like two of your lines are out of order. You start the process before setting up an event handler to capture the output. It's possible the process is just finishing before the event handler is added.
Switch the lines like so.
p.OutputDataReceived += ...
p.Start();
Redirecting the stream is asynchronous and will potentially continue after the process has terminated. It is mentioned by Umar to cancel after process termination process.CancelOutputRead(). However that has data loss potential.
This is working reliably for me:
process.WaitForExit(...);
...
while (process.StandardOutput.EndOfStream == false)
{
Thread.Sleep(100);
}
I didn't try this approach but I like the suggestion from Sly:
if (process.WaitForExit(timeout))
{
process.WaitForExit();
}
You need to call p.Start() to actually run the process after you set the StartInfo. As it is, your function is probably hanging on the WaitForExit() call because the process was never actually started.
The answer from Judah did not work for me (or is not complete) as the application was exiting after the first BeginOutputReadLine();
This works for me as a complete snippet, reading the constant output of a ping:
var process = new Process();
process.StartInfo.FileName = "ping";
process.StartInfo.Arguments = "google.com -t";
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.UseShellExecute = false;
process.OutputDataReceived += (sender, a) => Console.WriteLine(a.Data);
process.Start();
process.BeginOutputReadLine();
process.WaitForExit();
Here's a method that I use to run a process and gets its output and errors :
public static string ShellExecute(this string path, string command, TextWriter writer, params string[] arguments)
{
using (var process = Process.Start(new ProcessStartInfo { WorkingDirectory = path, FileName = command, Arguments = string.Join(" ", arguments), UseShellExecute = false, RedirectStandardOutput = true, RedirectStandardError = true }))
{
using (process.StandardOutput)
{
writer.WriteLine(process.StandardOutput.ReadToEnd());
}
using (process.StandardError)
{
writer.WriteLine(process.StandardError.ReadToEnd());
}
}
return path;
}
For example :
#"E:\Temp\MyWorkingDirectory".ShellExecute(#"C:\Program Files\Microsoft SDKs\Windows\v6.0A\Bin\svcutil.exe", Console.Out);
I am using iperf-2.0.5-2-win32 tool to find network bandwidth. I have written codes in c# which opens the cmd prompt, pass iperf parameters to start server side & client side. iperf-2.0.5-2-win32 exe will not open directly, need to open through cmd prompt only.
At present the output(Transfer rate & Bandwidth) is displaying on cmd prompt itself. I want these output to be displayed in textbox
I have tried StreamReader also. But it takes null, I have also tried OutputDataReceived Event, its also taking null.
Found few codes for ipconfig & ping.but those were not working with iperf codes.
button_click event(),
{
Process Client_proc = new Process();
ProcessStartInfo Client_command = new ProcessStartInfo("cmd.exe");
string ip = txtIP.Text;
Client_command.CreateNoWindow = true;
Client_command.WindowStyle = ProcessWindowStyle.Hidden;
Client_command.WorkingDirectory = #"E:\Iperf\RunEXE_Through_Application\iperf-2.0.5-2-win32";
Client_command.Arguments = "/c START iperf -c " + ip;
Client_proc.StartInfo = Client_command;
Client_command.RedirectStandardOutput = true;
Client_command.UseShellExecute = false;
Client_proc.OutputDataReceived += new DataReceivedEventHandler(Client_proc_OutputDataReceived);
Client_proc.Start();
Client_proc.BeginOutputReadLine();
Client_proc.WaitForExit();
}
void Client_proc_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
if (e.Data != null)
{
string newLine = e.Data.Trim() + Environment.NewLine;
MethodInvoker append = () => txtOutput.Text += newLine;
txtOutput.BeginInvoke(append);
}
}
Plz help me.Earlier responses are appreciated
Thanks
you use this complete code for your disposal
It is not perfect (some problems when using multiple streams )
public void RunProcess(string FileName, string Arguments, bool EventWhenExit )
{
process = new Process();
process.EnableRaisingEvents = true;
process.OutputDataReceived += new DataReceivedEventHandler(OnDataReceivedEvent);
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.CreateNoWindow = true;
process.StartInfo.LoadUserProfile = false;
process.StartInfo.UseShellExecute = false;
process.StartInfo.FileName = FileName; // Gets or sets the application or document to start.
process.StartInfo.Arguments = Arguments;//Gets or sets the set of command-line arguments to use when starting the application
Thread.Sleep(1000);
if (EventWhenExit)
{
process.EnableRaisingEvents = true;
process.Exited += new EventHandler(myprocess_Exited);/*New line */
}
process.Start();
process.BeginOutputReadLine();
PID = process.Id;
}
private void myprocess_Exited(object sender, EventArgs e)
{
process.Refresh();
Thread.Sleep(2000);
onProcessEnd(this, "ENDOF " + Proc.ToString());
Console.WriteLine("Process exsiting ");
}
private void OnDataReceivedEvent(object sender, DataReceivedEventArgs e)
{
string OutputFromProcess = e.Data;
//fire event to event handler class for further use
onDataOutputFromProcess(this, OutputFromProcess, Proc.ToString());
}
than in your GUI layer you should bind to onDataOutputFromProcess event
there you should have something like
if (screenToPrint.InvokeRequired) //&& this.Visible)
{
try
{
this.Invoke(new Action<AppendToScreenParam>(AppendTextFullConfig), new object[] { append });
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
return;
}
else
{
screenToPrint.SelectionFont = font;
screenToPrint.SelectionColor = append.Color;
//screenToPrint.AppendText(append.Message);
string TextToPrint = string.Format("{0}\n", append.Message);
screenToPrint.AppendText(TextToPrint);
}
}
Maybe it is because iperf process is returning error. Subscribe the ErrorDataReceived event with Client_proc.ErrorDataReceived += Client_proc_ErrorDataReceived; and see the results. If command returns error, you can see the error message as output.
void Client_proc_ErrorDataReceived(object sender, DataReceivedEventArgs e)
{
if (e.Data != null)
{
this.txtOutput.BeginInvoke(new MethodInvoker(() => { this.txtOutput.Text = e.Data; }));
}
}