Detaching process from powershell hosted in C# application - c#

We have a C# application that executes PowerShell scripts as an extension point, we don't have access to change this code but it is pretty much the following:
string command = #"C:\temp.ps1";
var fileName = "powershell";
var args = $"-ExecutionPolicy unrestricted . '{command}'";
var process = CreateProcess(fileName, args);
ExecuteProcess(ref process);
private Process CreateProcess(string fileName, string args)
{
return new Process
{
StartInfo =
{
FileName = fileName,
Arguments = args,
RedirectStandardError = true,
RedirectStandardOutput = true,
UseShellExecute = false
}
};
}
private int ExecuteProcess(ref Process proc)
{
proc.Start();
string text = string.Empty;
string text2 = string.Empty;
while (!proc.HasExited)
{
Thread.Sleep(1000);
text += proc.StandardOutput.ReadToEnd();
text2 += proc.StandardError.ReadToEnd();
}
proc.WaitForExit();
text2 += proc.StandardError.ReadToEnd();
text += proc.StandardOutput.ReadToEnd();
Console.WriteLine(text);
Console.WriteLine(text2);
return proc.ExitCode;
}
We have a PowerShell script that gets executed from this code that has a long-running process, to keep this simple we'll just use ping.exe with a -t argument.
ping -t google.com
We want to be able to fork the ping.exe process so that the c# application can resume execution as soon as possible and that the ping.exe in this example continues on it's merry way.
I've tried to run Start-Process inside the powershell script but this still just blocks the execution of the C# application until all the processes have fully executed (so it eventually runs to completion):
Start-Process ping -ArgumentList "-t","google.com" -RedirectStandardOutput ".\out.log" -RedirectStandardError ".\err.log"
I've also tried to run Start-Job and wrap the start process in a separate job, however, this seems to start the job but never completes
Start-Job -ScriptBlock { Start-Process ping -ArgumentList "-t","google.com" -RedirectStandardOutput ".\out.log" -RedirectStandardError ".\err.log" }
Is there any way to start a new process from within PowerShell and allow the C# application to continue executing?

I've kinda found a workaround - if I pass in -Verb Open to Start-Process it seems to resume execution to the C# application straight away. The only problem is that you can't redirect the standard out or error to files.
Start-Process ping -ArgumentList "-t","google.com" -Verb Open

Related

Kill Process in ffmpeg in c#

I'm using Process class to execute commands in ffmpeg like this:
string command = "/C ffmpeg -re -i test.mp4 -f mpegts udp://127.0.0.1:" + port.Text;
process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
process.StartInfo.Arguments = command;
process.Start();
this code streams video to network, but I want to stop streaming when I click on button
I used process.kill() but the process still streaming even if I closed application
How can I stop process in background or send ctrl+c to it ?
The leading "/C" indicates that you start it via cmd.exe?
In that case process corresponds to cmd which in turn starts ffmpeg. Thus killing cmd doesn't kill ffmpeg.
string command = "-re -i test.mp4 -f mpegts udp://127.0.0.1:" + port.Text;
process.StartInfo.FileName ="ffmpeg";
process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
process.StartInfo.Arguments = command;
process.Start();
process.Kill(); should work then.
So I was going through the same trouble of starting and stopping ffmpeg process in my selenium Nunit test. After bit of struggle I was able to create a simple solution. Sending as "q" a input to the process window of ffmpeg gracefully stops the process and the video recording is not corrupt as well.
here is my c# code to start the ffmpeg and stop it after execution.
Create a bat file to start your ffmpeg (you will be calling this batfile from your c# code)
In you selenium test , create a recording class and 2 methods to start and stop the recording(in my case I was starting the bat file before all test as in calling the executeScreenRecordingBatFile method in onetimesetup attribute to start the recording and calling the StopScreenRecording method in onetimeteardown ) Sample code below.
using System.Diagnostics;
using System.IO;
namespace FunctionalTests
{
public class Recording
{
public static Process process;
public static void executeScreenRecordingBatFile()
{
try
{
process = new Process();
process.StartInfo.FileName = #"C:\Program Files (x86)\StartScreenRecording.bat";
process.StartInfo.CreateNoWindow = true;
process.StartInfo.RedirectStandardInput = true;// this required to send input to the current process window.
bool started = process.Start();
if (started==true)
{
Console.WriteLine("Bat file started");
}
}
catch (Exception ex)
{
Console.WriteLine(ex.StackTrace.ToString());
throw;
}
}
public static void StopScreenRecording()
{
StreamWriter myStreamWriter = process.StandardInput; // this required to send StandardInput stream, nothing fancy
myStreamWriter.WriteLine("q"); //this will send q as an input to the ffmpeg process window making it stop , please cross check in task manager once if the ffmpeg is still running or closed.
}
}
}
I created a method to kill ffmpeg process.
private void KillAllFFMPEG()
{
Process killFfmpeg = new Process();
ProcessStartInfo taskkillStartInfo = new ProcessStartInfo
{
FileName = "taskkill",
Arguments = "/F /IM ffmpeg.exe",
UseShellExecute = false,
CreateNoWindow = true
};
killFfmpeg.StartInfo = taskkillStartInfo;
killFfmpeg.Start();
}
Just call it wherever you want.
UPDATE 1
In order to kill just one instance of the FFMPEG process, we need to get it's PID first. When you define your ffmpeg process for streaming, define it in the global scope and use following command to get the PID after it is initialized.
int myProcessId = FfmpegProcess.Id;
Then call the following
private void KillFFMPEGByPID(int PID)
{
Process killFfmpeg = new Process();
ProcessStartInfo taskkillStartInfo = new ProcessStartInfo
{
FileName = "taskkill",
Arguments = "/PID " + Convert.ToString(PID) + " /T",
UseShellExecute = false,
CreateNoWindow = true
};
killFfmpeg.StartInfo = taskkillStartInfo;
killFfmpeg.Start();
}
This will kill only the process with the given PID. /T flag at the end of the argument determines that whole process tree will be killed.
Cheers

C#: Calling a php script and beeing able to stop it

I am currently working on a C# Program which needs to call a local PHP script and write its output to a file. The problem is, that I need to be able to stop the execution of the script.
First, I tried to call cmd.exe and let cmd write the output to the file which worked fine. But I found out, that killing the cmd process does not stop the php cli.
So I tried to call php directly, redirect its output and write it from the C# code to a file. But here the problem seems to be, that the php cli does not terminate when the script is done. process.WaitForExit() does not return, even when I am sure that the script has been fully executed.
I cannot set a timeout to the WaitForExit(), because depending on the arguments, the script may take 3 minutes or eg. 10 hours.
I do not want to kill just a random php cli, there may be others currently running.
What is the best way to call a local php script from C#, writing its output to a file and beeing able to stop the execution?
Here is my current code:
// Create the process
var process = new System.Diagnostics.Process();
process.EnableRaisingEvents = true;
process.StartInfo.UseShellExecute = false;
process.StartInfo.FileName = "php.exe";
// CreateExportScriptArgument returns something like "file.php arg1 arg2 ..."
process.StartInfo.Arguments = CreateExportScriptArgument(code, this.content, this.options);
process.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
process.StartInfo.RedirectStandardOutput = true;
// Start the process or cancel, if the process should not run
if (!this.isRunning) { return; }
this.currentProcess = process;
process.Start();
// Get the output
var output = process.StandardOutput;
// Wait for the process to finish
process.WaitForExit();
this.currentProcess = null;
To kill the process I am using:
// Mark as not running to prevent starting new
this.isRunning = false;
// Kill the process
if (this.currentProcess != null)
{
this.currentProcess.Kill();
}
Thanks for reading!
EDIT
That the cli does not return seems to be not reproducible. When I test a different script (without arguments) it works, probably its the script or the passing of the arguments.
Running my script from cmd works just fine, so the script should not be the problem
EDIT 2
When disabling RedirectStandardOutput, the cli quits. could it be, that I need to read the output, before the process finishes? Or does the process wait, when some kind of buffer is full?
EDIT 3: Problem solved
Thanks to VolkerK, I / we found a solution. The problem was, that WaitForExit() did not get called, when the output is not read (probably due to a full buffer in the standard output). My script wrote much output.
What works for me:
process.Start();
// Get the output
var output = process.StandardOutput;
// Read the input and write to file, live to avoid reading / writing to much at once
using (var file = new StreamWriter("path\\file", false, new UTF8Encoding()))
{
// Read each line
while (!process.HasExited)
{
file.WriteLine(output.ReadLine());
}
// Read the rest
file.Write(output.ReadToEnd());
// flush to file
file.Flush();
}
Since the problem was that the output buffer was full and therefore the php process stalled while waiting to send its output, asynchronously reading the output in the c# program is the solution.
class Program {
protected static /* yeah, yeah, it's only an example */ StringBuilder output;
static void Main(string[] args)
{
// Create the process
var process = new System.Diagnostics.Process();
process.EnableRaisingEvents = true;
process.StartInfo.UseShellExecute = false;
process.StartInfo.FileName = "php.exe";
process.StartInfo.Arguments = "-f path\\test.php mu b 0 0 pgsql://user:pass#x.x.x.x:5432/nominatim";
process.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
process.StartInfo.RedirectStandardOutput = true;
output = new StringBuilder();
process.OutputDataReceived += process_OutputDataReceived;
// Start the process
process.Start();
process.BeginOutputReadLine();
// Wait for the process to finish
process.WaitForExit();
Console.WriteLine("test");
// <-- do something with Program.output here -->
Console.ReadKey();
}
static void process_OutputDataReceived(object sender, System.Diagnostics.DataReceivedEventArgs e)
{
if (!String.IsNullOrEmpty(e.Data)) {
// edit: oops the new-line/carriage-return characters are not "in" e.Data.....
// this _might_ be a problem depending on the actual output.
output.Append(e.Data);
output.Append(Environment.NewLine);
}
}
}
see also: https://msdn.microsoft.com/en-us/library/system.diagnostics.process.beginoutputreadline%28v=vs.110%29.aspx

C# Program automation - Program hangs/doesn't work

I've been trying to make a program to automate the process of running different processes on my computer. So far I've got the following program running a console version of BleachBit(It's like CCleaner), the process appears in task manager, it hits around 25kb process RAM then CPU usage goes to 0% and just sits there doing nothing for ages and never quits.
Is there something wrong I'm doing in my code that could cause this to happen?
I've tried editing the app.manifest to make sure the program has to be run as admin in case it needed more privileges
Also when running similar code in a bat file to run the program, it's opens its own windows and runs fine, so I'm not sure. Any help in the right direction would be fantastic.
The code I'm running is below.
static void Main(string[] args)
{
string Log = "";
if (File.Exists(Environment.CurrentDirectory + "\\BleachBit\\bleachbit_console.exe"))
{
Log += "File exists";
Log += RunProgramCapturingOutput("\\BleachBit\\bleachbit_console.exe", "--preset --clean");
}
else
Log += "Program not found. Please place at \\BleachBit\\bleachbit_console.exe";
File.WriteAllText("log.txt", Log);
Console.ReadLine();
}
public static string RunProgramCapturingOutput(string filename, string arguments)
{
ProcessStartInfo processInfo = new ProcessStartInfo()
{
FileName = Environment.CurrentDirectory + filename,
Arguments = arguments,
CreateNoWindow = false,
UseShellExecute = false,
WorkingDirectory = Path.GetDirectoryName(Environment.CurrentDirectory + filename),
RedirectStandardError = false,
RedirectStandardOutput = true
};
Process process = Process.Start(processInfo);
process.WaitForExit();
string output = output = process.StandardOutput.ReadToEnd();
Console.WriteLine("Output: " + output);
process.Close();
return output;
}
Switching these lines to this:
string output = output = process.StandardOutput.ReadToEnd();
process.WaitForExit();
allows to avoid deadlocks. The program seems to be a relatively slow running program due to hard-drive I/O, just give it time and you'll see it complete.
I found this deadlock issue from https://msdn.microsoft.com/en-us/library/system.diagnostics.process.standardoutput(v=vs.110).aspx
Where it states in a code block: "// To avoid deadlocks, always read the output stream first and then wait."

External tool fails to output in my app but outputs nicely in CMD screen

I am trying to use the GFIX tool that gets shipped with Firebird Database inside my C#/WPF Application to execute certain commands on the database.
Firebird http://www.firebirdsql.org/en/firebird-2-5-3-upd1/
Gfix http://www.firebirdsql.org/manual/gfix.html
To do this I use the following code:
public string RunExternalExe(string filename, string arguments = null)
{
var process = new Process();
process.StartInfo.FileName = filename;
if (!string.IsNullOrEmpty(arguments))
{
process.StartInfo.Arguments = arguments;
}
process.StartInfo.CreateNoWindow = true;
process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardError = true;
process.StartInfo.RedirectStandardOutput = true;
var stdOutput = new StringBuilder();
process.OutputDataReceived += (sender, args) => stdOutput.Append(args.Data);
string stdError = null;
try
{
process.Start();
process.BeginOutputReadLine();
stdError = process.StandardError.ReadToEnd();
process.WaitForExit();
}
catch (Exception e)
{
throw new Exception("OS error while executing " + Format(filename, arguments) + ": " + e.Message, e);
}
if (process.ExitCode == 0)
{
return stdOutput.ToString();
}
else
{
var message = new StringBuilder();
if (!string.IsNullOrEmpty(stdError))
{
message.AppendLine(stdError);
}
if (stdOutput.Length != 0)
{
message.AppendLine("Std output:");
message.AppendLine(stdOutput.ToString());
}
throw new Exception(Format(filename, arguments) + " finished with exit code = " + process.ExitCode + ": " + message);
}
}
private string Format(string filename, string arguments)
{
return "'" + filename +
((string.IsNullOrEmpty(arguments)) ? string.Empty : " " + arguments) +
"'";
}
Found there
How To: Execute command line in C#, get STD OUT results
also I tried every other approach that gets explained in that question, but it still doesn't get me any output.
I try to execute the following command
gfix.exe -user foo -pa foo -shut single -force 0 app1:\bar.fdb
What I see if I execute it in CMD is the following output
"Your user name and password are not defined. Ask your database administrator to set up a Firebird login."
That's an obvious error because user foo with password foo doesn't exist.
So my problem isn't the error itself, its just the fact that I do NOT get this output inside my C# application not matter what I tried so far.
Since I am seeing the error output in my CMD screen it should get output in my C# application or is there any possibility that the tool itself is blocking the output and I don't have a chance to get it?
What I tried so far:
Calling the gfix.exe itself with the arguments.
Calling a bat that contains the call to gfix.exe with its arguments.
Calling CMD with /c or /k that calls the gfix.exe with arguments.
Calling CMD with /c or /k that calls a bat that calls the gfix.exe.
I believe I tried all possible combinations of calling this tool but still I don't get an output.
Also I have tried both RedirectStandardError and RedirectStandardOutput, with async/sync approaches (Begin.. and ReadToEnd), also I tried to input the arguments with the help of RedirectStandardInput and wrote the lines exactly as I would type it with CMD, first a cd "C:\Test" and than the call to gfix.exe all in vain...
Further info the tool works fine if I input everything correctly its runs through and does exactly what it should do, but I would also like to catch when the tool fails and want to output the corresponding error.
Edit:
Notice that I tried the following now, without my C# app involved only doubleclick the bat or executing it in CMD.
I have modified my test bat file to this:
gfix.exe -user foo -pa foo -shut single -force 0 app1:/bar.fdb > Test.txt 2> error.txt
Which creates 2 Text files - both empty.
If I run this .bat in CMD no error is displayed, if I remove the 2> error.txt the error message again gets displayed in the CMD screen. So the redirect seems to "work" only that my txt files are empty... could the gfix tool block this?!?
This works for me:
using (var process = Process.Start(
new ProcessStartInfo
{
FileName = fileName,
Arguments = args,
WindowStyle = ProcessWindowStyle.Hidden,
CreateNoWindow = true,
RedirectStandardError = true,
UseShellExecute = false,
}))
{
process.WaitForExit();
if (process.ExitCode != 0)
{
var errorMessage = process.StandardError.ReadToEnd();
Assert.Fail(errorMessage);
}
}
Note the RedirectStandardError = true.
When error happens gfix outputs it not to stdout, but to stderr. This is obvious and std behavior.

C#.Net: Why is my Process.Start() hanging?

I'm trying to run a batch file, as another user, from my web app. For some reason, the batch file hangs! I can see "cmd.exe" running in the task manager, but it just sits there forever, unable to be killed, and the batch file is not running. Here's my code:
SecureString password = new SecureString();
foreach (char c in "mypassword".ToCharArray())
password.AppendChar(c);
ProcessStartInfo psi = new ProcessStartInfo();
psi.WorkingDirectory = #"c:\build";
psi.FileName = Environment.SystemDirectory + #"\cmd.exe";
psi.Arguments = "/q /c build.cmd";
psi.UseShellExecute = false;
psi.UserName = "builder";
psi.Password = password;
Process.Start(psi);
If you didn't guess, this batch file builds my application (a different application than the one that is executing this command).
The Process.Start(psi); line returns immediately, as it should, but the batch file just seems to hang, without executing. Any ideas?
EDIT: See my answer below for the contents of the batch file.
The output.txt never gets created.
I added these lines:
psi.RedirectStandardOutput = true;
Process p = Process.Start(psi);
String outp = p.StandardOutput.ReadLine();
and stepped through them in debug mode. The code hangs on the ReadLine(). I'm stumped!
I believe I've found the answer. It seems that Microsoft, in all their infinite wisdom, has blocked batch files from being executed by IIS in Windows Server 2003. Brenden Tompkins has a work-around here:
http://codebetter.com/blogs/brendan.tompkins/archive/2004/05/13/13484.aspx
That won't work for me, because my batch file uses IF and GOTO, but it would definitely work for simple batch files.
Why not just do all the work in C# instead of using batch files?
I was bored so i wrote this real quick, it's just an outline of how I would do it since I don't know what the command line switches do or the file paths.
using System;
using System.IO;
using System.Text;
using System.Security;
using System.Diagnostics;
namespace asdf
{
class StackoverflowQuestion
{
private const string MSBUILD = #"path\to\msbuild.exe";
private const string BMAIL = #"path\to\bmail.exe";
private const string WORKING_DIR = #"path\to\working_directory";
private string stdout;
private Process p;
public void DoWork()
{
// build project
StartProcess(MSBUILD, "myproject.csproj /t:Build", true);
}
public void StartProcess(string file, string args, bool redirectStdout)
{
SecureString password = new SecureString();
foreach (char c in "mypassword".ToCharArray())
password.AppendChar(c);
ProcessStartInfo psi = new ProcessStartInfo();
p = new Process();
psi.WindowStyle = ProcessWindowStyle.Hidden;
psi.WorkingDirectory = WORKING_DIR;
psi.FileName = file;
psi.UseShellExecute = false;
psi.RedirectStandardOutput = redirectStdout;
psi.UserName = "builder";
psi.Password = password;
p.StartInfo = psi;
p.EnableRaisingEvents = true;
p.Exited += new EventHandler(p_Exited);
p.Start();
if (redirectStdout)
{
stdout = p.StandardOutput.ReadToEnd();
}
}
void p_Exited(object sender, EventArgs e)
{
if (p.ExitCode != 0)
{
// failed
StringBuilder args = new StringBuilder();
args.Append("-s k2smtpout.secureserver.net ");
args.Append("-f build#example.com ");
args.Append("-t josh#example.com ");
args.Append("-a \"Build failed.\" ");
args.AppendFormat("-m {0} -h", stdout);
// send email
StartProcess(BMAIL, args.ToString(), false);
}
}
}
}
Without seeing the build.cmd it's hard to tell what is going on, however, you should build the path using Path.Combine(arg1, arg2); It's the correct way to build a path.
Path.Combine( Environment.SystemDirectory, "cmd.exe" );
I don't remember now but don't you have to set UseShellExecute = true ?
Another possibility to "debug" it is to use standardoutput and then read from it:
psi.RedirectStandardOutput = True;
Process proc = Process.Start(psi);
String whatever = proc.StandardOutput.ReadLine();
In order to "see" what's going on, I'd suggest you transform the process into something more interactive (turn off Echo off) and put some "prints" to see if anything is actually happening. What is in the output.txt file after you run this?
Does the bmail actually executes?
Put some prints after/before to see what's going on.
Also add "#" to the arguments, just in case:
psi.Arguments = #"/q /c build.cmd";
It has to be something very simple :)
My guess would be that the build.cmd is waiting for some sort of user-interaction/reply. If you log the output of the command with the "> logfile.txt" operator at the end, it might help you find the problem.
Here's the contents of build.cmd:
#echo off
set path=C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727;%path%
msbuild myproject.csproj /t:Build > output.txt
IF NOT ERRORLEVEL 1 goto :end
:error
bmail -s k2smtpout.secureserver.net -f build#example.com -t josh#example.com -a "Build failed." -m output.txt -h
:end
del output.txt
As you can see, I'm careful not to output anything. It all goes to a file that gets emailed to me if the build happens to fail. I've actually been running this file as a scheduled task nightly for quite a while now. I'm trying to build a web app that allows me to run it on demand.
Thanks for everyone's help so far! The Path.Combine tip was particularly useful.
I think cmd.exe hangs if the parameters are incorrect.
If the batch executes correctly then I would just shell execute it like this instead.
ProcessStartInfo psi = new ProcessStartInfo();
Process p = new Process();
psi.WindowStyle = ProcessWindowStyle.Hidden;
psi.WorkingDirectory = #"c:\build";
psi.FileName = #"C:\build\build.cmd";
psi.UseShellExecute = true;
psi.UserName = "builder";
psi.Password = password;
p.StartInfo = psi;
p.Start();
Also it could be that cmd.exe just can't find build.cmd so why not give the full path to the file?
What are the endlines of you batch? If the code hangs on ReadLine, then the problem might be that it's unable to read the batch fileā€¦

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