I would like to redirect the Process's standard output to a string for later parsing.
I would also like to see the output on the screen, while the process is running, and not only when it finishes it's run.
Is that even possible?
Use RedirectStandardOutput.
Sample from MSDN:
// Start the child process.
Process p = new Process();
// Redirect the output stream of the child process.
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = "Write500Lines.exe";
p.Start();
// Do not wait for the child process to exit before
// reading to the end of its redirected stream.
// p.WaitForExit();
// Read the output stream first and then wait.
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Also see OutputDataReceived and BeginOutputReadLine() for an alternative to ReadToEnd(), that will better fulfill your "see output while the process is running" requirement.
If you want to execute an exe from your c# application and get the output from it then you can use the below code
System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.FileName = "PATH TO YOUR FILE";
p.StartInfo.UseShellExecute = false;
p.StartInfo.Arguments = metalType + " " + graphHeight + " " + graphWidth;
p.StartInfo.CreateNoWindow = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.EnableRaisingEvents = true;
p.Start();
svgText = p.StandardOutput.ReadToEnd();
using(StreamReader s = p.StandardError)
{
string error = s.ReadToEnd();
p.WaitForExit(20000);
}
Don't forgete to write p.EnableRaisingEvents = true;
Related
I have a console program written in c++, and I would like to continually check its output to use in my c# project.
This is the code I've tried to steal from another StackOverflow question, but with no luck.
Edit:( By no luck, I mean: the output is pretty much empty, although if I set p.StartInfo.CreateNoWindow to false, I can see my script.exe launch and output into its window. )
Process p = new Process();
p.StartInfo.FileName = #"external\script.exe";
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.CreateNoWindow = true;
p.Start();
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine("Output:");
Console.WriteLine(output);
I had a similar issue and it had to do with where the output was going. The solution was to run cmd and execute my script from the cmd process. See this answer to another question for more information. reading from stdout and stderr together Your new code would look like:
Process p = new Process();
p.StartInfo.FileName = "cmd.exe";
p.StartInfo.Arguments = "/c yourscriptpath.exe 2>&1";
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.CreateNoWindow = true;
p.Start();
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine("Output:");
Console.WriteLine(output);
I have an exe file that I call it from my c# code by using Process namespace in c#.
I catch output by using ReadToEnd() method. (in exe source code i used a print method for my desired output).
the problem is when my output is getting larger the executing of exe file is got crashed and hanged.
Is there any limitation of output size when calling exe function?
Process p = new Process();
p.StartInfo.FileName = command;
p.StartInfo.UseShellExecute = false;
p.StartInfo.CreateNoWindow = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.Arguments = args;
p.Start();
p.WaitForExit();
string output = p.StandardOutput.ReadToEnd();
return output;
What you're experiencing is a deadlock. That situation is described in the documentation. In order to avoid it, make sure you read the output before waiting for the child process to exit.
p.Start();
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
I remember having the same problem as you're describing here, and what I did back then was something like this:
private string RunProcess(string command, string args)
{
StringBuilder sb = new StringBuilder();
Process p = new Process();
p.StartInfo.FileName = command;
p.StartInfo.UseShellExecute = false;
p.StartInfo.CreateNoWindow = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.Arguments = args;
p.OutputDataReceived += (sender, eventArgs) => { sb.Append(eventArgs.Data); };
p.Start();
p.WaitForExit();
return sb.ToString();
}
I want to get the output of an execution in c# and I referred to this question. But I only have the output be printed on the console but not stored in the specified string. Here is my code: `
System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
//p.StartInfo.CreateNoWindow = true;
p.StartInfo.FileName = "ffmpeg.exe";
p.StartInfo.Arguments = " -i 1.flv";
p.Start();
p.WaitForExit();
string output = p.StandardOutput.ReadToEnd();
Console.WriteLine(output);
Console.ReadLine();`
The output string is still empty after the execution of these codes. Plus if I keep the line p.StartInfo.CreateNoWindow = true;, no words will be printed on the console at all, why this happen? I thought the line will only stop a new window being created.
Move string output = p.StandardOutput.ReadToEnd(); inside wait for exit.
How are you going to read data when it already exit.
System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
//p.StartInfo.CreateNoWindow = true;
p.StartInfo.FileName = "ffmpeg.exe";
p.StartInfo.Arguments = " -i 1.flv";
p.Start();
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine(output);
Console.ReadLine();`
I'd try the following:
System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = "ffmpeg.exe";
p.StartInfo.Arguments = " -i 1.flv";
p.Start();
while (!p.HasExited)
{
string output = p.StandardOutput.ReadToEnd();
}
I also suggest you have a look at the BeginReadOutputLine method in this example given in the MS documentation. Being asynchronous, it will be called even though you use WaitForExit.
A boiled down version of this is:
// Start the asynchronous read of the output stream.
p.OutputDataReceived += new DataReceivedEventHandler(OutputHandler);
p.EnableRaisingEvents = true;
p.BeginOutputReadLine();
p.Start();
p.WaitForExit();
p.Close();
private static void OutputHandler(object sendingProcess, DataReceivedEventArgs outLine)
{
// Collect the command output.
if (!String.IsNullOrEmpty(outLine.Data))
{
numOutputLines++;
// Add the text to the output
Console.WriteLine(Environment.NewLine +
"[" + numOutputLines.ToString() + "] - " + outLine.Data);
}
}
How about switch those two line?
p.WaitForExit();
string output = p.StandardOutput.ReadToEnd();
New to programming and I'm writing a process which is supposed to open up the cmd prompt, run the command
"/k nslookup 123.123.123.123;
And then redirect the standard output into a string so the data can be manipulated. I've tried various combinations but cannot get the program to output anything except my last line of "Press any key to close".
I feel as though I'm missing something very simple as I can't find anything wrong with my code. Does anyone have any suggestions?
try
{
string strCmdText;
strCmdText = "/k nslookup 123.123.123.123";
// Start the process.
Process p = new Process();
//The name of the application to start, or the name of a document
p.StartInfo.FileName = "C:/Windows/System32/cmd.exe";
// On start run the string strCmdText as a command
p.StartInfo.Arguments = strCmdText;
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.CreateNoWindow = true;
p.Start();
// Read the output stream first and then wait.
string output = p.StandardOutput.ReadLine();
p.WaitForExit();
Console.WriteLine(output);
}
catch (Exception)
{
Console.WriteLine( "error");
}
//Wait for user to press a button to close window
Console.WriteLine("Press any key...");
Console.ReadLine();
I think it is because the command prompt is not exiting. Instead of passing arguments, write them to the standard input and then exit, like this:
p.StartInfo.Arguments = "";
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.RedirectStandardInput = true;
p.StartInfo.CreateNoWindow = true;
p.Start();
p.StandardInput.WriteLine("/k nslookup 123.123.123.123");
p.StandardInput.WriteLine("exit");
// Read the output stream first and then wait.
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine(output);
I have a doubt, when I create a new process iexplore, and this process opens one single page, I would like know if the page loads correctly. How can I learn if the page load fails ?. Is there any way to catch an error from iexplore process?
I have this demo code, but doesn't work correctly
string navegador = "C:\\program files (x86)\\Internet Explorer\\iexplore.exe";
Process p = new Process();
p.StartInfo.FileName = navegador;
ProcessStartInfo processStartInfo = new ProcessStartInfo(navegador);
p.EnableRaisingEvents = false;
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.CreateNoWindow = true;
p.StartInfo = processStartInfo;
p.StartInfo.Arguments = "google.com";
p.Start();
Process currentProcess = Process.GetCurrentProcess();
Process[] localByName = Process.GetProcessesByName("iexplore");
Process[] localAll = Process.GetProcesses();
p.OutputDataReceived += new DataReceivedEventHandler(
prsProjectTypes_OutputDataReceived);
p.BeginOutputReadLine();
errorMessage = p.StandardError.ReadToEnd();
p.WaitForExit();
Thank you for any help.
Assuming you are working WPF, you should look at the Web Browser control rather than launching a separate process. This will give you access to the LoadCompleted event which seems to be what you're looking for.