c# ProcessStartInfo.Start - reading output but with a timeout

Question

If you want to start another process and wait (with time out) to finish you can use the following (from MSDN).

//Set a time-out value.
int timeOut=5000;
//Ge         


        

Answer 1

void OpenWithStartInfo()
{
    ProcessStartInfo startInfo = new ProcessStartInfo("IExplore.exe", "Default2.aspx");
    startInfo.WindowStyle = ProcessWindowStyle.Minimized;
    Process p = Process.Start(startInfo);
    p.WaitForInputIdle();  
    //p.WaitForExit(2);
    p.Kill();
}

Answer 2

you can try modifying the first method to something like this

Process p = Process.Start(pInfo);
string output = string.Empty;
Thread t = new Thread(() =>  output = p.StandardOutput.ReadToEnd() );
t.Start();
//Wait for window to finish loading.
p.WaitForInputIdle();
//Wait for the process to exit or time out.
p.WaitForExit(timeOut);

Answer 3

Just add everything from the first example below the WaitForExit() call to the second example.

Answer 4

This technique will hang if the output buffer is filled with more that 4KB of data. A more foolproof method is to register delegates to be notified when something is written to the output stream. I've already suggested this method before in another post:

ProcessStartInfo processInfo = new ProcessStartInfo("Write500Lines.exe");
processInfo.ErrorDialog = false;
processInfo.UseShellExecute = false;
processInfo.RedirectStandardOutput = true;
processInfo.RedirectStandardError = true;

Process proc = Process.Start(processInfo);

// You can pass any delegate that matches the appropriate 
// signature to ErrorDataReceived and OutputDataReceived
proc.ErrorDataReceived += (sender, errorLine) => { if (errorLine.Data != null) Trace.WriteLine(errorLine.Data); };
proc.OutputDataReceived += (sender, outputLine) => { if (outputLine.Data != null) Trace.WriteLine(outputLine.Data); };
proc.BeginErrorReadLine();
proc.BeginOutputReadLine();

proc.WaitForExit();

Answer 5

You don't have to combine the two - the Process class has an event that fires when output is sent to the StandardOutput - OutputDataReceived.

If you subscribe to the event, you will be able to read output as it arrives and in your main program loop you can still timeout.

Answer 6

You could also use the APM, like this:

Define a delegate for the ReadToEnd call:

private delegate string ReadToEndDelegate();

Then use the delegate to call the method like this:

ReadToEndDelegate asyncCall = reader.ReadToEnd;
IAsyncResult asyncResult = asyncCall.BeginInvoke(null, null);
asyncResult.AsyncWaitHandle.WaitOne(TimeSpan.FromSeconds(10));
asyncCall.EndInvoke(asyncResult);

EDIT: Error handling removed for clarity.