Passing ffmpeg stream to c# window - c#

Is it possible to pass FFMPEG video stream to C# window? Now it opens as new process in new window, I just simply want to pass it to my own SessionWindow.
At this moment I execute ffplay like this:
public void ExecuteCommandSync(String command, String args)
{
try
{
System.Diagnostics.ProcessStartInfo procStartInfo =
new System.Diagnostics.ProcessStartInfo("\"" + command + "\"", args);
procStartInfo.RedirectStandardOutput = true;
procStartInfo.UseShellExecute = false;
procStartInfo.CreateNoWindow = true;
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo = procStartInfo;
proc.Start();
string result = proc.StandardOutput.ReadToEnd();
Debug.WriteLine(result);
}
catch (Exception objException)
{
}
}
private void button2_Click(object sender, EventArgs e)
{
String runPlay = #"C:\FFMPEG\bin\ffplay.exe";
String Random = "udp://127.0.0.1:1234";
this.ExecuteCommandSync(runPlay, Random);
}
PS. I don't want to use Windows Media Player since I want this app to look and work like remote desktop.

Looks like I found answer.
Process ProcFFplay = new Process();
ProcFFplay.StartInfo.FileName = #"C:\FFMPEG\bin\ffplay.exe";
ProcFFplay.StartInfo.Arguments = #"-probesize 32 udp://192.168.88.228:12340";
ProcFFplay.StartInfo.CreateNoWindow = true;
ProcFFplay.StartInfo.RedirectStandardOutput = true;
ProcFFplay.StartInfo.UseShellExecute = false;
ProcFFplay.EnableRaisingEvents = true;
ProcFFplay.OutputDataReceived += (o, k) => Debug.WriteLine(k.Data ?? "NULL", "ffplay");
ProcFFplay.ErrorDataReceived += (o, k) => Debug.WriteLine(k.Data ?? "NULL", "ffplay");
ProcFFplay.Exited += (o, k) => Debug.WriteLine("Exited", "ffplay");
ProcFFplay.Start();
Thread.Sleep(4500);//this is time which you need to wait to get first frames approximately
SetParent(ProcFFplay.MainWindowHandle, this.panel1.Handle);
MoveWindow(ProcFFplay.MainWindowHandle, -5, -30, 1200, 800, true); //these parameteres may look weird but you hide top "stripe" using them.
Enjoy.

Related

Sending DOS commands using Process - missing data on OutputDataReceived callback

I have been looking for a solution before posting but I gave up!
I just want to interactively send DOS command using Standard input. It works well but I always don't get the last line (the prompt line) on the OutputDataReceived callback.
Any ideas?
Process p = null;
private void Start_Click(object sender, EventArgs e)
{
p = new Process();
p.StartInfo = new ProcessStartInfo();
p.EnableRaisingEvents = true;
p.StartInfo.CreateNoWindow = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.RedirectStandardInput = true;
p.StartInfo.UseShellExecute = false;
p.StartInfo.FileName = "cmd.exe";
p.ErrorDataReceived += ErrorDataReceived;
p.OutputDataReceived += OutputDataReceived;
p.Start();
p.BeginErrorReadLine();
p.BeginOutputReadLine();
p.StandardInput.WriteLine("dir");
}
private void OutputDataReceived(object sender, DataReceivedEventArgs e)
{
Console.WriteLine(e.Data + "\n");
}
private void WriteToStandardInput_Click(object sender, EventArgs e)
{
p.StandardInput.WriteLine(txt_command.Text); //can be "dir" or "cd temp"
}
Adding p.StandardInput.Close() solves the problem, reason is when you close the input stream it actually terminates the process (which you start using 'p.start'). So as I said, you need start separate process for each command.
~Nilesh
OK, I have found a solution... I have created 2 tasks as shown below which are reading constantly from the output and error stream and print it to a rich text box. The trick was not to use BeginErrorReadLine and BeginOutputReadLine.
I hope I was able to help others...
public partial class Form1 : Form
{
private Process p = new Process();
private SynchronizationContext context;
public Form1()
{
InitializeComponent();
context = SynchronizationContext.Current;
}
private void Start_Click (object sender, EventArgs e)
{
p.StartInfo = new ProcessStartInfo();
p.EnableRaisingEvents = true;
p.StartInfo.CreateNoWindow = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.RedirectStandardInput = true;
p.StartInfo.FileName = "cmd.exe";
p.StartInfo.UseShellExecute = false;
p.Start();
Task.Run(() => ReadFromStreamLoop(p.StandardOutput));
Task.Run(() => ReadFromStreamLoop(p.StandardError));
}
private void ReadFromStreamLoop (StreamReader s)
{
int count = 0;
char[] buffer = new char[1024];
do
{
StringBuilder builder = new StringBuilder();
count = s.Read(buffer, 0, 1024);
builder.Append(buffer, 0, count);
context.Post(new SendOrPostCallback(delegate (object state)
{
richTextBox1.AppendText(builder.ToString());
}), null);
} while (count > 0);
}
private void WriteToStandardInput_Click (object sender, EventArgs e)
{
p.StandardInput.WriteLine(txt_command.Text); //can be "dir" or "cd temp"
}
}
If you are looking for event end of command execution, then every time spawn a new process. At the end of processing you can show the prompt on main process. Manage your environment variable through invoking(main) process.
See the example on - https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.process.outputdatareceived?view=netframework-4.7.2

C# FFMPEG Process and Multiple files

I am working on a C# Form tool that will help me convert all of my phone and DSLR video to HEVC, currently, i have a program that uploads the photos and videos to different directories in my home server each time i connect to the WiFi. Once a month or so, i manually convert all the videos, but thought I would automate the process.. I have the Form working perfectly for processing 1 file. but get into trouble when processing a Directory (with possible sub-directories) all at once..
Sorry, this is long, just want to be thorough. here is the button calls
private void processFile_Click(object sender, EventArgs e)
{
OpenFileDialog file = new OpenFileDialog();
file.InitialDirectory = baseMediaDirectory;
if (file.ShowDialog() == DialogResult.OK)
{
ProcessSinlgeFile(file.FileName);
}
}
(above)for one file and (below) for a directory
private void processDirectory_Click(object sender, EventArgs e)
{
FolderBrowserDialog file = new FolderBrowserDialog();
file.SelectedPath = baseMediaDirectory;
if(file.ShowDialog() == DialogResult.OK)
{
ProcessDirectoryOfFiles(file.SelectedPath);
}
}
private void ProcessDirectoryOfFiles(string selectedPath)
{
List<string> listOfFiles = GetAllFiles(selectedPath);
foreach (string s in listOfFiles)
{
ProcessSinlgeFile(s);
}
}
both ultimately call this method, to do some checks and setup
private void ProcessSinlgeFile(string fileName)
{
if (IsAcceptableMediaFile(fileName))
{
outputWindow.AppendText("File to Process: " + fileName);
processMediaFile =
new MediaFileWrapper(this.outputWindow, new MediaFile(fileName), new NReco.VideoInfo.FFProbe());
if (processMediaFile.OkToProcess)
{
int initialCRFValue = 15;
//ultrafast superfast veryfast faster fast medium slow slower veryslow placebo
string intialSpeed = "veryfast";
try {
ConvertToMPEG(processMediaFile.getFFMPEGCommand(initialCRFValue, intialSpeed), processMediaFile);
}
catch
{
// at somepoint, we'll catch a bad file size (or compression)
// then change the CRF value and/or compression speed
}
}
}
}
ultimately I get to this Method and run into trouble.
private async void ConvertToMPEG(string arguments, MediaFileWrapper processMediaFile)
{
startTime = DateTime.Now;
watch = new Stopwatch();
watch.Start();
progressBar1.Minimum = 0;
progressBar1.Maximum = processMediaFile.GetTotalMilliseconds();
// Start the child process.
p = new Process();
//Setup filename and arguments
outputWindow.AppendText("ffmpeg " + arguments);
p.StartInfo.Arguments = arguments;
p.StartInfo.FileName = "ffmpeg.exe";
p.StartInfo.UseShellExecute = false;
// Redirect the output stream of the child process.
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.RedirectStandardInput = true;
// capture the date for stdout and std error
// note FFMPEG uses Stderr exclusively
p.ErrorDataReceived += new DataReceivedEventHandler(ErrorDataReceived);
p.OutputDataReceived += new DataReceivedEventHandler(OutputDataReceived);
// Hide Console Window
p.StartInfo.CreateNoWindow = true;
p.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
p.Start();
p.BeginErrorReadLine();
p.BeginOutputReadLine();
await p.WaitForExitAsync();
}
and WaitForExitAsync is in another class because in can not be in here with a Form
public static Task WaitForExitAsync(this Process process,
CancellationToken cancellationToken = default(CancellationToken))
{
var tcs = new TaskCompletionSource<object>();
process.EnableRaisingEvents = true;
process.Exited += (sender, args) => tcs.TrySetResult(null);
if (cancellationToken != default(CancellationToken))
cancellationToken.Register(tcs.SetCanceled);
return tcs.Task;
}
however, single files work fine, when I call a directory through, it continuously starts processes for each file, trying to run them all at the same time. You can see I tried implementing this
process.WaitForExit() asynchronously
with no luck.

Execute multiple command lines with output

I want to perform some command lines to display the result after each input.
Process p = new Process();
ProcessStartInfo info = new ProcessStartInfo();
info.FileName = "cmd.exe";
info.RedirectStandardInput = true;
info.UseShellExecute = false;
p.StartInfo = info;
p.Start();
using (StreamWriter sw = p.StandardInput)
{
if (sw.BaseStream.CanWrite)
{
sw.WriteLine("ftp");
//output
sw.WriteLine("open ftp.server.com");
//output
sw.WriteLine("username");
//output
sw.WriteLine("password");
//output
}
}
Help me to understand how to make the output result after each sw.WriteLine(...)?
Updated
It is not working with ftp. Why?
Initialization:
Test test = new Test();
test.start();
Console.ReadKey();
Class Test:
class Test
{
static StringBuilder StdOutput = new StringBuilder();
Process p = null;
Queue<string> cmdQueue = new Queue<string>();
public void start(){
cmdQueue = new Queue<string>();
cmdQueue.Enqueue("cd c:\\");
cmdQueue.Enqueue("dir");
cmdQueue.Enqueue("ftp");
cmdQueue.Enqueue("open us1.hostedftp.com");
cmdQueue.Enqueue("z3r9#ya.ru");
cmdQueue.Enqueue("123456");
cmdQueue.Enqueue("dir");
setupProcess();
startProcess();
}
private void setupProcess()
{
p = new Process();
ProcessStartInfo info = new ProcessStartInfo();
info.FileName = "cmd";
info.CreateNoWindow = true;
info.RedirectStandardOutput = true;
info.RedirectStandardInput = true;
info.UseShellExecute = false;
p.OutputDataReceived += new DataReceivedEventHandler(OutputDataHandler);
StdOutput = new StringBuilder();
p.StartInfo = info;
}
private async void startProcess()
{
p.Start();
p.BeginOutputReadLine();
using (StreamWriter sw = p.StandardInput)
{
if (sw.BaseStream.CanWrite)
{
while (cmdQueue.Count > 0)
{
string cmd = cmdQueue.Dequeue();
if (cmd != null & cmd != "")
{
await sw.WriteLineAsync(cmd);
Thread.Sleep(100);
//System.Console.WriteLine(StdOutput);
}
else
{
break;
}
}
Console.WriteLine(StdOutput);
}
p.WaitForExit();
}
}
private static void OutputDataHandler(object sendingProcess, DataReceivedEventArgs outLine)
{
if (!String.IsNullOrEmpty(outLine.Data))
{
StdOutput.Append(Environment.NewLine + outLine.Data);
//System.Console.WriteLine(Environment.NewLine + outLine.Data);
}
}
}
I assume that you are actually asking about how to catch outputs from all the commands you want to have executed in the (one) process.
Here is a version of a solution I came up with a long time ago, when I was a rookie here..
The trick is to collect the output as is comes along by listening to events the Process will trigger whenever output gets created: OutputDataReceived and ErrorDataReceived. We need to run things async for this to work, so it will look a little more complicated than the usual examples, which only have one process executing one command..:
First a few variables:
Queue<string> cmdQueue = new Queue<string>();
static StringBuilder StdOutput = new StringBuilder();
static StringBuilder ErrOutput = new StringBuilder();
Process p = null;
Task processTask = null;
bool processIsRunning = false;
Here is a button click event that starts processing all commands from a multiline TextBox. Output gets collected in the two StringBuilders; when the queue is empty, I wait a little longer..:
private void button1_Click(object sender, EventArgs e)
{
cmdQueue = new Queue<string>(tb_commands.Lines.ToList());
setupProcess();
startProcessTask();
while (cmdQueue.Count > 0) Thread.Sleep(100);
Thread.Sleep(500);
tb_out.AppendText(StdOutput + "\r\n" + ErrOutput + "\r\n");
}
Here is the routine that set up the Process. Here we register two events that will notify us when there are lines in the output streams..:
private void setupProcess()
{
p = new Process();
ProcessStartInfo info = new ProcessStartInfo();
info.FileName = "cmd.exe";
info.CreateNoWindow = true;
info.RedirectStandardOutput = true;
info.RedirectStandardError = true;
info.RedirectStandardInput = true;
info.UseShellExecute = false;
p.OutputDataReceived += new DataReceivedEventHandler(OutputDataHandler);
p.ErrorDataReceived += new DataReceivedEventHandler(ErrorDataHandler);
StdOutput = new StringBuilder();
ErrOutput = new StringBuilder();
p.StartInfo = info;
}
After the setup we can start a Task that will start our Process asynchonously..:
private void startProcessTask()
{
var task = Task.Factory.StartNew(() => startProcess());
processTask = task;
}
..and finally here is the async method that after starting the Process and beginning with the asynchronous read operations on the redirected streams, keeps feeding it all lines from the command queue.
private async void startProcess()
{
try { p.Start(); processIsRunning = true; } catch
{
ErrOutput.Append("\r\nError starting cmd process.");
processIsRunning = false;
}
p.BeginOutputReadLine();
p.BeginErrorReadLine();
using (StreamWriter sw = p.StandardInput)
{
if (sw.BaseStream.CanWrite)
do
{
try
{
string cmd = cmdQueue.Dequeue();
if (cmd != null & cmd != "") await sw.WriteLineAsync(cmd);
} catch { }
} while (processIsRunning);
try { p.WaitForExit(); } catch { ErrOutput.Append("WaitForExit Error.\r\n"); }
}
}
The last pieces are the two events we have registered for reading the output from the two streams and adding them to the StringBuilders:
private static void OutputDataHandler(object sendingProcess, DataReceivedEventArgs outLine)
{
if (!String.IsNullOrEmpty(outLine.Data))
{
StdOutput.Append(Environment.NewLine + outLine.Data);
}
}
private static void ErrorDataHandler(object sendingProcess, DataReceivedEventArgs outLine)
{
if (!String.IsNullOrEmpty(outLine.Data))
{
ErrOutput.Append(Environment.NewLine + outLine.Data);
}
}
Note that this works fine for all sorts of commands you can feed into the process, including FTP. Here I change my codepage, show the images I have before, log in to an FTP server, call up the help page, cd and dir, download an image, close the connection and check the images I have now..:
One Caveat: There must be something wrong in the way I wrote this, as VS keeps complaining about a System.InvalidOperationException and the exe file hogs ~10% cpu. Helping me out would be very much appreciated..

RedirectStandard Output/Error wont call my event for Standard Output/Error

hi i'm trying to build a parser for my System to Manage my Tekkit Server i am using C# but i have RedirectStandardOutput on my Tekkit Server process and there is a method set-up to then send that output to my console after adding to a List but it's not adding to a List<string>
Here is my code:
public void StartServer(string maxMem, string minMem, string path)
{
ThreadStart server = new ThreadStart(delegate() { StartServerThread(maxMem, minMem, path); });
server.Invoke();
}
private void StartServerThread(string maxMem, string minMem, string TekkitPath)
{
try
{
TekkitServer.StartInfo.FileName = "java";
TekkitServer.StartInfo.Arguments = String.Format("-Xmx{0} -Xms{1} -jar \"" + TekkitPath + "\" -nojline nogui", maxMem, minMem);
TekkitServer.StartInfo.UseShellExecute = false;
TekkitServer.StartInfo.RedirectStandardInput = true;
TekkitServer.StartInfo.RedirectStandardOutput = true;
TekkitServer.OutputDataReceived += new DataReceivedEventHandler(TekkitServer_OutputDataReceived);
IsStarted = TekkitServer.Start();
TekkitServerInput = TekkitServer.StandardInput;
}
catch (Exception)
{
}
}
void TekkitServer_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
/*B*/recordedData.Add(e.Data);
Console.Out.WriteLine(e.Data);
}
Where /*B*/ is a break point, the breakpoint is never activating
By default, the standard output is directed at the console window.
If you need to do something with it, you need to redirect it, hence, you need to set RedirectStandardOutput = true; for the event to be fired.
Edit: This is my working code (with error handling and logging omitted):
public int ExecuteCommand(CommandParameters parameters)
{
Process process = new Process();
process.StartInfo.RedirectStandardInput = true;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
process.OutputDataReceived += StdOutputHandler;
process.ErrorDataReceived += StdErrorHandler;
process.StartInfo.UseShellExecute = false;
process.StartInfo.FileName = ...;
process.StartInfo.Arguments = ...;
process.Start();
process.BeginErrorReadLine();
process.BeginOutputReadLine();
process.WaitForExit(parameters.Timeout);
return process.ExitCode;
}
private void StdOutputHandler(object sendingProcess, DataReceivedEventArgs outdata)
{
if (!string.IsNullOrEmpty(outdata.Data))
{
OutputMessages.Add(outdata.Data);
}
}
Most likely the missing link in your code is the BeginOutputReadLine that actually gets the handler method on it's way.
Also, I use a fresh Process object and that I wait on it to finish it's job, so no interference with previous calls is possible.

How To: Execute command line in C#, get STD OUT results

How do I execute a command-line program from C# and get back the STD OUT results? Specifically, I want to execute DIFF on two files that are programmatically selected and write the results to a text box.
// 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 = "YOURBATCHFILE.bat";
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();
Code is from MSDN.
Here's a quick sample:
//Create process
System.Diagnostics.Process pProcess = new System.Diagnostics.Process();
//strCommand is path and file name of command to run
pProcess.StartInfo.FileName = strCommand;
//strCommandParameters are parameters to pass to program
pProcess.StartInfo.Arguments = strCommandParameters;
pProcess.StartInfo.UseShellExecute = false;
//Set output of program to be written to process output stream
pProcess.StartInfo.RedirectStandardOutput = true;
//Optional
pProcess.StartInfo.WorkingDirectory = strWorkingDirectory;
//Start the process
pProcess.Start();
//Get program output
string strOutput = pProcess.StandardOutput.ReadToEnd();
//Wait for process to finish
pProcess.WaitForExit();
There one other parameter I found useful, which I use to eliminate the process window
pProcess.StartInfo.CreateNoWindow = true;
this helps to hide the black console window from user completely, if that is what you desire.
// usage
const string ToolFileName = "example.exe";
string output = RunExternalExe(ToolFileName);
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.AppendLine(args.Data); // Use AppendLine rather than Append since args.Data is one line of output, not including the newline character.
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) +
"'";
}
The accepted answer on this page has a weakness that is troublesome in rare situations. There are two file handles which programs write to by convention, stdout, and stderr.
If you just read a single file handle such as the answer from Ray, and the program you are starting writes enough output to stderr, it will fill up the output stderr buffer and block. Then your two processes are deadlocked. The buffer size may be 4K.
This is extremely rare on short-lived programs, but if you have a long running program which repeatedly outputs to stderr, it will happen eventually. This is tricky to debug and track down.
There are a couple good ways to deal with this.
One way is to execute cmd.exe instead of your program and use the /c argument to cmd.exe to invoke your program along with the "2>&1" argument to cmd.exe to tell it to merge stdout and stderr.
var p = new Process();
p.StartInfo.FileName = "cmd.exe";
p.StartInfo.Arguments = "/c mycmd.exe 2>&1";
Another way is to use a programming model which reads both handles at the same time.
var p = new Process();
p.StartInfo.FileName = "cmd.exe";
p.StartInfo.Arguments = #"/c dir \windows";
p.StartInfo.CreateNoWindow = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardInput = false;
p.OutputDataReceived += (a, b) => Console.WriteLine(b.Data);
p.ErrorDataReceived += (a, b) => Console.WriteLine(b.Data);
p.Start();
p.BeginErrorReadLine();
p.BeginOutputReadLine();
p.WaitForExit();
System.Diagnostics.ProcessStartInfo psi =
new System.Diagnostics.ProcessStartInfo(#"program_to_call.exe");
psi.RedirectStandardOutput = true;
psi.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
psi.UseShellExecute = false;
System.Diagnostics.Process proc = System.Diagnostics.Process.Start(psi); ////
System.IO.StreamReader myOutput = proc.StandardOutput;
proc.WaitForExit(2000);
if (proc.HasExited)
{
string output = myOutput.ReadToEnd();
}
You will need to use ProcessStartInfo with RedirectStandardOutput enabled - then you can read the output stream. You might find it easier to use ">" to redirect the output to a file (via the OS), and then simply read the file.
[edit: like what Ray did: +1]
One-liner run command:
new Process() { StartInfo = new ProcessStartInfo("echo", "Hello, World") }.Start();
Read output of command in shortest amount of reable code:
var cliProcess = new Process() {
StartInfo = new ProcessStartInfo("echo", "Hello, World") {
UseShellExecute = false,
RedirectStandardOutput = true
}
};
cliProcess.Start();
string cliOut = cliProcess.StandardOutput.ReadToEnd();
cliProcess.WaitForExit();
cliProcess.Close();
In case you also need to execute some command in the cmd.exe, you can do the following:
// 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 = "cmd.exe";
p.StartInfo.Arguments = "/C vol";
p.Start();
// Read the output stream first and then wait.
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine(output);
This returns just the output of the command itself:
You can also use StandardInput instead of StartInfo.Arguments:
// Start the child process.
Process p = new Process();
// Redirect the output stream of the child process.
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardInput = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = "cmd.exe";
p.Start();
// Read the output stream first and then wait.
p.StandardInput.WriteLine("vol");
p.StandardInput.WriteLine("exit");
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine(output);
The result looks like this:
Since the most answers here dont implement the using statemant for IDisposable and some other stuff wich I think could be nessecary I will add this answer.
For C# 8.0
// Start a process with the filename or path with filename e.g. "cmd". Please note the
//using statemant
using myProcess.StartInfo.FileName = "cmd";
// add the arguments - Note add "/c" if you want to carry out tge argument in cmd and
// terminate
myProcess.StartInfo.Arguments = "/c dir";
// Allows to raise events
myProcess.EnableRaisingEvents = true;
//hosted by the application itself to not open a black cmd window
myProcess.StartInfo.UseShellExecute = false;
myProcess.StartInfo.CreateNoWindow = true;
// Eventhander for data
myProcess.Exited += OnOutputDataRecived;
// Eventhandler for error
myProcess.ErrorDataReceived += OnErrorDataReceived;
// Eventhandler wich fires when exited
myProcess.Exited += OnExited;
// Starts the process
myProcess.Start();
//read the output before you wait for exit
myProcess.BeginOutputReadLine();
// wait for the finish - this will block (leave this out if you dont want to wait for
// it, so it runs without blocking)
process.WaitForExit();
// Handle the dataevent
private void OnOutputDataRecived(object sender, DataReceivedEventArgs e)
{
//do something with your data
Trace.WriteLine(e.Data);
}
//Handle the error
private void OnErrorDataReceived(object sender, DataReceivedEventArgs e)
{
Trace.WriteLine(e.Data);
//do something with your exception
throw new Exception();
}
// Handle Exited event and display process information.
private void OnExited(object sender, System.EventArgs e)
{
Trace.WriteLine("Process exited");
}
Here is small example:
using System;
using System.Diagnostics;
class Program
{
static void Main(string[] args)
{
var p = Process.Start(
new ProcessStartInfo("git", "branch --show-current")
{
CreateNoWindow = true,
UseShellExecute = false,
RedirectStandardError = true,
RedirectStandardOutput = true,
WorkingDirectory = Environment.CurrentDirectory
}
);
p.WaitForExit();
string branchName =p.StandardOutput.ReadToEnd().TrimEnd();
string errorInfoIfAny =p.StandardError.ReadToEnd().TrimEnd();
if (errorInfoIfAny.Length != 0)
{
Console.WriteLine($"error: {errorInfoIfAny}");
}
else {
Console.WriteLine($"branch: {branchName}");
}
}
}
I believe this is shortest form.
Please notice that most of command line tools easily confuse standard output and standard error, sometimes it makes sense just to clue those together into single string.
Also p.ExitCode might be sometimes useful.
Example above serves for purpose of writing command line utility like tools if you want to do it by yourself. Please note that for cli automation it's also possible to use Cake Frosten and Cake Git extension.
You can launch any command line program using the Process class, and set the StandardOutput property of the Process instance with a stream reader you create (either based on a string or a memory location). After the process completes, you can then do whatever diff you need to on that stream.
This might be useful for someone if your attempting to query the local ARP cache on a PC/Server.
List<string[]> results = new List<string[]>();
using (Process p = new Process())
{
p.StartInfo.CreateNoWindow = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.UseShellExecute = false;
p.StartInfo.Arguments = "/c arp -a";
p.StartInfo.FileName = #"C:\Windows\System32\cmd.exe";
p.Start();
string line;
while ((line = p.StandardOutput.ReadLine()) != null)
{
if (line != "" && !line.Contains("Interface") && !line.Contains("Physical Address"))
{
var lineArr = line.Trim().Split(' ').Select(n => n).Where(n => !string.IsNullOrEmpty(n)).ToArray();
var arrResult = new string[]
{
lineArr[0],
lineArr[1],
lineArr[2]
};
results.Add(arrResult);
}
}
p.WaitForExit();
}
This may not be the best/easiest way, but may be an option:
When you execute from your code, add " > output.txt" and then read in the output.txt file.
There is a ProcessHelper Class in PublicDomain open source code which might interest you.
Julian's solution is tested working with some minor corrections. The following is an example that also used https://sourceforge.net/projects/bat-to-exe/ GenericConsole.cs and https://www.codeproject.com/Articles/19225/Bat-file-compiler program.txt for args part:
using System;
using System.Text; //StringBuilder
using System.Diagnostics;
using System.IO;
class Program
{
private static bool redirectStandardOutput = true;
private static string buildargument(string[] args)
{
StringBuilder arg = new StringBuilder();
for (int i = 0; i < args.Length; i++)
{
arg.Append("\"" + args[i] + "\" ");
}
return arg.ToString();
}
static void Main(string[] args)
{
Process prc = new Process();
prc.StartInfo = //new ProcessStartInfo("cmd.exe", String.Format("/c \"\"{0}\" {1}", Path.Combine(Environment.CurrentDirectory, "mapTargetIDToTargetNameA3.bat"), buildargument(args)));
//new ProcessStartInfo(Path.Combine(Environment.CurrentDirectory, "mapTargetIDToTargetNameA3.bat"), buildargument(args));
new ProcessStartInfo("mapTargetIDToTargetNameA3.bat");
prc.StartInfo.Arguments = buildargument(args);
prc.EnableRaisingEvents = true;
if (redirectStandardOutput == true)
{
prc.StartInfo.UseShellExecute = false;
}
else
{
prc.StartInfo.UseShellExecute = true;
}
prc.StartInfo.CreateNoWindow = true;
prc.OutputDataReceived += OnOutputDataRecived;
prc.ErrorDataReceived += OnErrorDataReceived;
//prc.Exited += OnExited;
prc.StartInfo.RedirectStandardOutput = redirectStandardOutput;
prc.StartInfo.RedirectStandardError = redirectStandardOutput;
try
{
prc.Start();
prc.BeginOutputReadLine();
prc.BeginErrorReadLine();
prc.WaitForExit();
}
catch (Exception e)
{
Console.WriteLine("OS error: " + e.Message);
}
prc.Close();
}
// Handle the dataevent
private static void OnOutputDataRecived(object sender, DataReceivedEventArgs e)
{
//do something with your data
Console.WriteLine(e.Data);
}
//Handle the error
private static void OnErrorDataReceived(object sender, DataReceivedEventArgs e)
{
Console.WriteLine(e.Data);
}
// Handle Exited event and display process information.
//private static void OnExited(object sender, System.EventArgs e)
//{
// var process = sender as Process;
// if (process != null)
// {
// Console.WriteLine("ExitCode: " + process.ExitCode);
// }
// else
// {
// Console.WriteLine("Process exited");
// }
//}
}
The code need to compile inside VS2007, using commandline csc.exe generated executable will not show console output correctly, or even crash with CLR20r3 error. Comment out the OnExited event process, the console output of the bat to exe will be more like the original bat console output.
Just for fun, here's my completed solution for getting PYTHON output - under a button click - with error reporting. Just add a button called "butPython" and a label called "llHello"...
private void butPython(object sender, EventArgs e)
{
llHello.Text = "Calling Python...";
this.Refresh();
Tuple<String,String> python = GoPython(#"C:\Users\BLAH\Desktop\Code\Python\BLAH.py");
llHello.Text = python.Item1; // Show result.
if (python.Item2.Length > 0) MessageBox.Show("Sorry, there was an error:" + Environment.NewLine + python.Item2);
}
public Tuple<String,String> GoPython(string pythonFile, string moreArgs = "")
{
ProcessStartInfo PSI = new ProcessStartInfo();
PSI.FileName = "py.exe";
PSI.Arguments = string.Format("\"{0}\" {1}", pythonFile, moreArgs);
PSI.CreateNoWindow = true;
PSI.UseShellExecute = false;
PSI.RedirectStandardError = true;
PSI.RedirectStandardOutput = true;
using (Process process = Process.Start(PSI))
using (StreamReader reader = process.StandardOutput)
{
string stderr = process.StandardError.ReadToEnd(); // Error(s)!!
string result = reader.ReadToEnd(); // What we want.
return new Tuple<String,String> (result,stderr);
}
}

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