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);
Related
I would like to run an external command line program from my Mono/.NET app.
For example, I would like to run mencoder. Is it possible:
To get the command line shell output, and write it on my text box?
To get the numerical value to show a progress bar with time elapsed?
When you create your Process object set StartInfo appropriately:
var proc = new Process
{
StartInfo = new ProcessStartInfo
{
FileName = "program.exe",
Arguments = "command line arguments to your executable",
UseShellExecute = false,
RedirectStandardOutput = true,
CreateNoWindow = true
}
};
then start the process and read from it:
proc.Start();
while (!proc.StandardOutput.EndOfStream)
{
string line = proc.StandardOutput.ReadLine();
// do something with line
}
You can use int.Parse() or int.TryParse() to convert the strings to numeric values. You may have to do some string manipulation first if there are invalid numeric characters in the strings you read.
You can process your output synchronously or asynchronously.
1. Synchronous example
static void runCommand()
{
Process process = new Process();
process.StartInfo.FileName = "cmd.exe";
process.StartInfo.Arguments = "/c DIR"; // Note the /c command (*)
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
process.Start();
//* Read the output (or the error)
string output = process.StandardOutput.ReadToEnd();
Console.WriteLine(output);
string err = process.StandardError.ReadToEnd();
Console.WriteLine(err);
process.WaitForExit();
}
Note that it's better to process both output and errors: they must be handled separately.
(*) For some commands (here StartInfo.Arguments) you must add the /c directive, otherwise the process freezes in the WaitForExit().
2. Asynchronous example
static void runCommand()
{
//* Create your Process
Process process = new Process();
process.StartInfo.FileName = "cmd.exe";
process.StartInfo.Arguments = "/c DIR";
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
//* Set your output and error (asynchronous) handlers
process.OutputDataReceived += new DataReceivedEventHandler(OutputHandler);
process.ErrorDataReceived += new DataReceivedEventHandler(OutputHandler);
//* Start process and handlers
process.Start();
process.BeginOutputReadLine();
process.BeginErrorReadLine();
process.WaitForExit();
}
static void OutputHandler(object sendingProcess, DataReceivedEventArgs outLine)
{
//* Do your stuff with the output (write to console/log/StringBuilder)
Console.WriteLine(outLine.Data);
}
If you don't need to do complicate operations with the output, you can bypass the OutputHandler method, just adding the handlers directly inline:
//* Set your output and error (asynchronous) handlers
process.OutputDataReceived += (s, e) => Console.WriteLine(e.Data);
process.ErrorDataReceived += (s, e) => Console.WriteLine(e.Data);
Alright, for anyone who wants both Errors and Outputs read, but gets deadlocks with any of the solutions, provided in other answers (like me), here is a solution that I built after reading MSDN explanation for StandardOutput property.
Answer is based on T30's code:
static void runCommand()
{
//* Create your Process
Process process = new Process();
process.StartInfo.FileName = "cmd.exe";
process.StartInfo.Arguments = "/c DIR";
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
//* Set ONLY ONE handler here.
process.ErrorDataReceived += new DataReceivedEventHandler(ErrorOutputHandler);
//* Start process
process.Start();
//* Read one element asynchronously
process.BeginErrorReadLine();
//* Read the other one synchronously
string output = process.StandardOutput.ReadToEnd();
Console.WriteLine(output);
process.WaitForExit();
}
static void ErrorOutputHandler(object sendingProcess, DataReceivedEventArgs outLine)
{
//* Do your stuff with the output (write to console/log/StringBuilder)
Console.WriteLine(outLine.Data);
}
The standard .NET way of doing this is to read from the Process' StandardOutput stream. There is an example in the linked MSDN docs. Similar, you can read from StandardError, and write to StandardInput.
It is possible to get the command line shell output of a process as described here : http://www.c-sharpcorner.com/UploadFile/edwinlima/SystemDiagnosticProcess12052005035444AM/SystemDiagnosticProcess.aspx
This depends on mencoder. If it ouputs this status on the command line then yes :)
you can use shared memory for the 2 processes to communicate through, check out MemoryMappedFile
you'll mainly create a memory mapped file mmf in the parent process using "using" statement then create the second process till it terminates and let it write the result to the mmf using BinaryWriter, then read the result from the mmf using the parent process, you can also pass the mmf name using command line arguments or hard code it.
make sure when using the mapped file in the parent process that you make the child process write the result to the mapped file before the mapped file is released in the parent process
Example:
parent process
private static void Main(string[] args)
{
using (MemoryMappedFile mmf = MemoryMappedFile.CreateNew("memfile", 128))
{
using (MemoryMappedViewStream stream = mmf.CreateViewStream())
{
BinaryWriter writer = new BinaryWriter(stream);
writer.Write(512);
}
Console.WriteLine("Starting the child process");
// Command line args are separated by a space
Process p = Process.Start("ChildProcess.exe", "memfile");
Console.WriteLine("Waiting child to die");
p.WaitForExit();
Console.WriteLine("Child died");
using (MemoryMappedViewStream stream = mmf.CreateViewStream())
{
BinaryReader reader = new BinaryReader(stream);
Console.WriteLine("Result:" + reader.ReadInt32());
}
}
Console.WriteLine("Press any key to continue...");
Console.ReadKey();
}
Child process
private static void Main(string[] args)
{
Console.WriteLine("Child process started");
string mmfName = args[0];
using (MemoryMappedFile mmf = MemoryMappedFile.OpenExisting(mmfName))
{
int readValue;
using (MemoryMappedViewStream stream = mmf.CreateViewStream())
{
BinaryReader reader = new BinaryReader(stream);
Console.WriteLine("child reading: " + (readValue = reader.ReadInt32()));
}
using (MemoryMappedViewStream input = mmf.CreateViewStream())
{
BinaryWriter writer = new BinaryWriter(input);
writer.Write(readValue * 2);
}
}
Console.WriteLine("Press any key to continue...");
Console.ReadKey();
}
to use this sample, you'll need to create a solution with 2 projects inside, then you take the build result of the child process from %childDir%/bin/debug and copy it to %parentDirectory%/bin/debug then run the parent project
childDir and parentDirectory are the folder names of your projects on the pc
good luck :)
You can log process output using below code:
ProcessStartInfo pinfo = new ProcessStartInfo(item);
pinfo.CreateNoWindow = false;
pinfo.UseShellExecute = true;
pinfo.RedirectStandardOutput = true;
pinfo.RedirectStandardInput = true;
pinfo.RedirectStandardError = true;
pinfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal;
var p = Process.Start(pinfo);
p.WaitForExit();
Process process = Process.Start(new ProcessStartInfo((item + '>' + item + ".txt"))
{
UseShellExecute = false,
RedirectStandardOutput = true
});
process.WaitForExit();
string output = process.StandardOutput.ReadToEnd();
if (process.ExitCode != 0) {
}
How to launch a process (such as a bat file, perl script, console program) and have its standard output displayed on a windows form:
processCaller = new ProcessCaller(this);
//processCaller.FileName = #"..\..\hello.bat";
processCaller.FileName = #"commandline.exe";
processCaller.Arguments = "";
processCaller.StdErrReceived += new DataReceivedHandler(writeStreamInfo);
processCaller.StdOutReceived += new DataReceivedHandler(writeStreamInfo);
processCaller.Completed += new EventHandler(processCompletedOrCanceled);
processCaller.Cancelled += new EventHandler(processCompletedOrCanceled);
// processCaller.Failed += no event handler for this one, yet.
this.richTextBox1.Text = "Started function. Please stand by.." + Environment.NewLine;
// the following function starts a process and returns immediately,
// thus allowing the form to stay responsive.
processCaller.Start();
You can find ProcessCaller on this link: Launching a process and displaying its standard output
I was running into the infamous deadlock problem when calling Process.StandardOutput.ReadLine and Process.StandardOutput.ReadToEnd.
My goal/use case is simple. Start a process and redirect it's output so I can capture that output and log it to the console via .NET Core's ILogger<T> and also append the redirected output to a file log.
Here's my solution using the built in async event handlers Process.OutputDataReceived and Process.ErrorDataReceived.
var p = new Process
{
StartInfo = new ProcessStartInfo(
command.FileName, command.Arguments
)
{
RedirectStandardOutput = true,
RedirectStandardError = true,
UseShellExecute = false,
}
};
// Asynchronously pushes StdOut and StdErr lines to a thread safe FIFO queue
var logQueue = new ConcurrentQueue<string>();
p.OutputDataReceived += (sender, args) => logQueue.Enqueue(args.Data);
p.ErrorDataReceived += (sender, args) => logQueue.Enqueue(args.Data);
// Start the process and begin streaming StdOut/StdErr
p.Start();
p.BeginOutputReadLine();
p.BeginErrorReadLine();
// Loop until the process has exited or the CancellationToken is triggered
do
{
var lines = new List<string>();
while (logQueue.TryDequeue(out var log))
{
lines.Add(log);
_logger.LogInformation(log)
}
File.AppendAllLines(_logFilePath, lines);
// Asynchronously sleep for some time
try
{
Task.Delay(5000, stoppingToken).Wait(stoppingToken);
}
catch(OperationCanceledException) {}
} while (!p.HasExited && !stoppingToken.IsCancellationRequested);
The solution that worked for me in win and linux is the folling
// GET api/values
[HttpGet("cifrado/{xml}")]
public ActionResult<IEnumerable<string>> Cifrado(String xml)
{
String nombreXML = DateTime.Now.ToString("ddMMyyyyhhmmss").ToString();
String archivo = "/app/files/"+nombreXML + ".XML";
String comando = " --armor --recipient bibankingprd#bi.com.gt --encrypt " + archivo;
try{
System.IO.File.WriteAllText(archivo, xml);
//String comando = "C:\\GnuPG\\bin\\gpg.exe --recipient licorera#local.com --armor --encrypt C:\\Users\\Administrador\\Documents\\pruebas\\nuevo.xml ";
ProcessStartInfo startInfo = new ProcessStartInfo() {FileName = "/usr/bin/gpg", Arguments = comando };
Process proc = new Process() { StartInfo = startInfo, };
proc.StartInfo.RedirectStandardOutput = true;
proc.StartInfo.RedirectStandardError = true;
proc.Start();
proc.WaitForExit();
Console.WriteLine(proc.StandardOutput.ReadToEnd());
return new string[] { "Archivo encriptado", archivo + " - "+ comando};
}catch (Exception exception){
return new string[] { archivo, "exception: "+exception.ToString() + " - "+ comando };
}
}
System.Diagnostics.Process is not the most pleasant to work with, so you may want to try CliWrap. It offers many different models for working with output, including piping, buffering, and real-time streaming. Here are some examples (taken from readme).
Simply launch a command line executable:
using CliWrap;
var result = await Cli.Wrap("path/to/exe")
.WithArguments("--foo bar")
.WithWorkingDirectory("work/dir/path")
.ExecuteAsync();
// Result contains:
// -- result.ExitCode (int)
// -- result.StartTime (DateTimeOffset)
// -- result.ExitTime (DateTimeOffset)
// -- result.RunTime (TimeSpan)
Launch a command line executable and buffer stdout/stderr in-memory:
using CliWrap;
using CliWrap.Buffered;
// Calling `ExecuteBufferedAsync()` instead of `ExecuteAsync()`
// implicitly configures pipes that write to in-memory buffers.
var result = await Cli.Wrap("path/to/exe")
.WithArguments("--foo bar")
.WithWorkingDirectory("work/dir/path")
.ExecuteBufferedAsync();
// Result contains:
// -- result.StandardOutput (string)
// -- result.StandardError (string)
// -- result.ExitCode (int)
// -- result.StartTime (DateTimeOffset)
// -- result.ExitTime (DateTimeOffset)
// -- result.RunTime (TimeSpan)
Launch a command line executable with manual pipe configuration:
using CliWrap
var buffer = new StringBuilder();
var result = await Cli.Wrap("foo")
.WithStandardOutputPipe(PipeTarget.ToFile("output.txt"))
.WithStandardErrorPipe(PipeTarget.ToStringBuilder(buffer))
.ExecuteAsync();
Launch a command line executable as an event stream:
using CliWrap;
using CliWrap.EventStream;
var cmd = Cli.Wrap("foo").WithArguments("bar");
await foreach (var cmdEvent in cmd.ListenAsync())
{
switch (cmdEvent)
{
case StartedCommandEvent started:
_output.WriteLine($"Process started; ID: {started.ProcessId}");
break;
case StandardOutputCommandEvent stdOut:
_output.WriteLine($"Out> {stdOut.Text}");
break;
case StandardErrorCommandEvent stdErr:
_output.WriteLine($"Err> {stdErr.Text}");
break;
case ExitedCommandEvent exited:
_output.WriteLine($"Process exited; Code: {exited.ExitCode}");
break;
}
}
Im running an exe through process in my c# program, i want the process to be completely invisible without the console of it popping up.
This is my code
Process process2 = new Process();
process2.StartInfo.FileName = "cmd.exe";
process2.StartInfo.UseShellExecute = false;
process2.StartInfo.CreateNoWindow = true;
process2.StartInfo.RedirectStandardOutput = true;
process2.StartInfo.RedirectStandardError = true;
process2.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
process2 = Process.Start(path3);
even with this code the console window still opens and shows, any help will be appreciated :)
Using
UseShellExecute = false; CreateNoWindow = true;
Should hide the process although it depends on the path in which you are opening, if the process has a force show
Try the following:
private void RunCmd(string exePath, string arguments = null)
{
//create new instance
ProcessStartInfo startInfo = new ProcessStartInfo(exePath, arguments);
startInfo.Arguments = arguments; //arguments
startInfo.CreateNoWindow = true; //don't create a window
startInfo.RedirectStandardError = true; //redirect standard error
startInfo.RedirectStandardOutput = true; //redirect standard output
startInfo.RedirectStandardInput = false;
startInfo.UseShellExecute = false; //if true, uses 'ShellExecute'; if false, uses 'CreateProcess'
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
startInfo.ErrorDialog = false;
//create new instance
using (Process p = new Process { StartInfo = startInfo, EnableRaisingEvents = true })
{
//subscribe to event and add event handler code
p.ErrorDataReceived += (sender, e) =>
{
if (!String.IsNullOrEmpty(e.Data))
{
//ToDo: add desired code
Debug.WriteLine("Error: " + e.Data);
}
};
//subscribe to event and add event handler code
p.OutputDataReceived += (sender, e) =>
{
if (!String.IsNullOrEmpty(e.Data))
{
//ToDo: add desired code
Debug.WriteLine("Output: " + e.Data);
}
};
p.Start(); //start
p.BeginErrorReadLine(); //begin async reading for standard error
p.BeginOutputReadLine(); //begin async reading for standard output
//waits until the process is finished before continuing
p.WaitForExit();
}
}
See also this post.
I fixed it by renaming the window instead ty for all your help
I have found many examples of coding on how to execute cmd.exe and execute a command, and execute even nslookup and interact, but the problem I am having is with a particular dos program that when it starts, it does not stop "outputting". here is some code and I will put a comment and the errors I get from C#
Here is how I have it setup in a more advanced way so I can receive output from the program on events
public void StartApplication(string appNameAndPath)
{
StreamReader outputStream;
Process p = new Process();
p.StartInfo.FileName = appNameAndPath;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.UseShellExecute = false;
p.StartInfo.CreateNoWindow = false;//for now just so I can see it
p.Start();
//here is my advanced example
if(advanced == true)
{
outputStream = p.StandardOutput;
DoReadOutPut();
}
else
{//here is a simple example
while (p.StandardOutput.ReadLine() != null) //this hangs here until the application exists
{
txt += (p.StandardOutput.ReadLine());
}
}
}
void DoReadOutput()
{
outputStream.BaseStream.BeginRead( readOutputBuffer, 0, readOutputBuffer.Length, new AsyncCallback( OnReadOutputCompleted ), null );
//this does sometimes fire but only with 0 bytes, on other dos programs it would say Memory read not allowed
}
void OnReadOutputCompleted( IAsyncResult result )
{
int cbRead = outputStream.BaseStream.EndRead( result );
ProcessOutput( readOutputBuffer, cbRead );
DoReadOutput();
}
private void ProcessOutput(byte[] buffer, int cbRead)
{
string text = p.StartInfo.StandardOutputEncoding.GetString(buffer, 0, 10000); //this is where it hangs until the program exits or is not writing anymore
this.Invoke((Action)delegate
{
SetTextBoxValue(text);//im doing this because im on another thread otherwise textBox1.Text - text"
});
}
I do not want to have to use API and GetText and create an engine to ReadLastLine, can anyone help me with this? I suppose you would want an example exe, creating a C# application that while(true){Console.WriteLine("bla");} would suffice as the example exe but not the exe I am having trouble with. The exe takes over the dos window and has an "old school interface"
async/await can help here....
await Exec(yourExe,parameters);
Task Exec(string exe,string args)
{
var tcs = new TaskCompletionSource<object>();
ProcessStartInfo psi = new ProcessStartInfo();
psi.FileName = exe;
psi.UseShellExecute = false;
psi.RedirectStandardOutput = true;
psi.Arguments = args;
var proc = Process.Start(psi);
proc.OutputDataReceived += (s, e) =>
{
this.Invoke((Action) (()=>richTextBox1.AppendText(e.Data + Environment.NewLine)));
};
proc.Exited += (s, e) => tcs.SetResult(null);
proc.EnableRaisingEvents = true;
proc.BeginOutputReadLine();
return tcs.Task;
}
You need to handle callback events to read streams:
startInfo.UseShellExecute = false;
startInfo.CreateNoWindow = true;
startInfo.RedirectStandardOutput = true;
startInfo.RedirectStandardError = true;
Process proc = new Process();
proc.StartInfo = startInfo;
proc.ErrorDataReceived += new DataReceivedEventHandler(DataReceiveHandler);
proc.OutputDataReceived += new DataReceivedEventHandler(DataReceiveHandler);
proc.Start();
proc.BeginErrorReadLine();
proc.BeginOutputReadLine();
proc.WaitForExit();
Code borrowed from this post
I'm making gui to rtmp-plugin that is commandline program. I need way to read output data from cmd program to three variables: downloaded, time and done.
In cmd output is exsample "3000 kb / 12 sec (12%)" without "". How I can get 3000 to downloaded variable without kb and 12 to time without sec and 12 to done without () and %. My code to run cmd process below.
int downloaded, time, done;
var proc = new Process
{
StartInfo = new ProcessStartInfo
{
FileName = "Data/yle-dl/yle-dl.exe",
Arguments = "-o pasila.flv http://areena.yle.fi/tv/1755554 --rtmpdump rtmpdump.exe ",
UseShellExecute = false,
RedirectStandardOutput = true,
CreateNoWindow = false
}
};
proc.Start();
You can catch program output and parse values using regex. Note that you should also catch error output as it happens often, that normal output is handled as an error.
Process process = new Process();
process.StartInfo.FileName = "Data/yle-dl/yle-dl.exe";
process.StartInfo.Arguments = "-o pasila.flv http://areena.yle.fi/tv/1755554 --rtmpdump rtmpdump.exe ";
process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
process.StartInfo.CreateNoWindow = true;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
process.StartInfo.UseShellExecute = false;
process.OutputDataReceived += new DataReceivedEventHandler(ReadOutput);
process.ErrorDataReceived += new DataReceivedEventHandler(ReadOutput);
process.Start();
process.BeginOutputReadLine();
process.BeginErrorReadLine();
process.WaitForExit();
private static void ReadOutput(object sender, DataReceivedEventArgs e)
{
if (e.Data != null)
{
Match m = Regex.Match(e.Data, "(\\d+)[^0-9]*(\\d+)[^0-9]*(\\d+)[^0-9]");
if (m.Success)
{
textBox1.Text = m.Result("$1");
string time = m.Result("$2");
string percent = m.Result("$3");
}
}
}
If there is already some kind of output from the commandline you can catch it by using BeginOutputReadLine.
Otherwise you can add the assembly to your program references and access the (if exists) variable that the program uses to indicate your state.
I am going to execute a Process (lame.exe) to encode a WAV file to MP3.
I want to process the STDOUT and STDERR of the process to display progress information.
Do I need to use threading? I can't get my head around it.
Some simple example code would be appreciated.
Thanks
If running via the Process class, you can redirect the streams so you may process them. You can read from stdout or stderr synchronously or asynchronously. To enable redirecting, set the appropriate redirection properties to true for the streams you want to redirect (e.g., RedirectStandardOutput) and set UseShellExecute to false. Then you can just start the process and read from the streams. You can also feed input redirecting stdin.
e.g., Process and print whatever the process writes to stdout synchronously
var proc = new Process()
{
StartInfo = new ProcessStartInfo(#"SomeProcess.exe")
{
RedirectStandardOutput = true,
UseShellExecute = false,
}
};
if (!proc.Start())
{
// handle error
}
var stdout = proc.StandardOutput;
string line;
while ((line = stdout.ReadLine()) != null)
{
// process and print
Process(line);
Console.WriteLine(line);
}
You should be able to listen to the STDOUT with the Process.OutputDataReceived event. There is an example on the MSDN page. There is also an Process.ErrorDataReceived event for STDERR.
There is an MSDN example for this... Here is a simplified version:
var StdOut = "";
var StdErr = "";
var stdout = new StringBuilder();
var stderr = new StringBuilder();
var psi = new ProcessStartInfo();
psi.FileName = #"something.exe";
psi.CreateNoWindow = true;
psi.UseShellExecute = false;
psi.RedirectStandardOutput = true;
psi.RedirectStandardError = true;
var proc = new Process();
proc.StartInfo = psi;
proc.OutputDataReceived += (sender, e) => { stdout.AppendLine(e.Data); };
proc.ErrorDataReceived += (sender, e) => { stderr.AppendLine(e.Data); };
proc.Start();
proc.BeginOutputReadLine();
proc.BeginErrorReadLine();
proc.WaitForExit(10000); // per sachin-joseph's comment
StdOut = stdout.ToString();
StdErr = stderr.ToString();