My application starts openvpn from the command line like this:
Dim cmdInfo As New ProcessStartInfo("cmd", "/K openvpn.exe " & Chr(34) & ovpnPath & Chr(34))
cmdInfo.WindowStyle = ProcessWindowStyle.Hidden
Process.Start(cmdInfo)
This works great but I have no way of closing openvpn gracefully. I could kill the process but then it doesn't remove the routes etc.
Now I'm looking for a way to send Ctrl+C or F4 to my hidden cmd window to make OpenVPN exit.
Dim opwnfilepath As String = "Opvn file path"
Dim Params As String = " --config """ & opwnfilepath & """
Dim p As New ProcessStartInfo
p.FileName = "C:\Program Files\OpenVPN\bin\openvpn.exe" ' add here openvpn.exe path
p.Arguments = Params
p.WindowStyle = ProcessWindowStyle.Hidden
Process.Start(p)
I use this code work good. if need show what happend in cmd change ProcessWindowStyle.Hidden to ProcessWindowStyle.Normal
Sorry I understand wrong :D
if you close openvpn in task manager , network gone back to your own
try this code
Dim arrProcessx() As Process = System.Diagnostics.Process.GetProcessesByName("openvpn")
For Each psx As Process In arrProcessx
psx.Kill()
Next
tested work for me.
As a small part of a project, I'm calling ffmpeg to convert a video - I worked from an old example that used some of the output to create a progress bar, which was hanging. Code below:
[initiation code common to both examples]
Dim inputFile, outputFile As String, myProcess As New Process
Dim psiProcInfo As New ProcessStartInfo, ffreader As StreamReader
inputFile = "C:\Users\mklefass\Downloads\Video 2017-08-16 21.01.39.mov"
outputFile = "C:\Users\mklefass\Downloads\tmp2\Output"
psiProcInfo.FileName = Application.StartupPath + "\ffmpeg.exe" 'Location Of FFMPEG.EXE
psiProcInfo.Arguments = " -i " & Chr(34) & inputFile & Chr(34) & " -vf fps=5 " & Chr(34) & outputFile & "%d.jpg" & Chr(34) 'start ffmpeg with command strFFCMD string
psiProcInfo.UseShellExecute = False 'use the shell execute command we always want no
psiProcInfo.WindowStyle = ProcessWindowStyle.Hidden 'hide the ffmpeg process window
psiProcInfo.RedirectStandardError = True 'Redirect the error out so we can read it
psiProcInfo.RedirectStandardOutput = True 'Redirect the standard out so we can read it
psiProcInfo.CreateNoWindow = True
[bit that changes]
myProcess.Start()
ffreader = myProcess.StandardError
Do
Try
If Not myProcess.HasExited Then
'Debug.WriteLine(ffreader.ReadLine)
End If
Catch
If Not myProcess.HasExited Then
MsgBox("Something went wrong")
End If
End Try
Loop Until myProcess.HasExited
MsgBox("done")
I then found another example that just called the executable and then continued when it was done - as below:
[same initialisation]
Debug.WriteLine("Starting...")
myProcess.Start()
strOutput = myProcess.StandardError.ReadToEnd
myProcess.WaitForExit()
myProcess.Close()
Debug.Write(strOutput)
MsgBox("done")
The second approach worked perfectly... What's different about the "exit state" that Process.HasExited and Process.WaitForExit look for?
thanks in advance i just want to know if theres a way to read the output from a running batch file in a vb.net program. Thanks!
As one commenter above mentions, you can run the batch file in a shell within your VB.NET program and then read the directed output. I have done this exactly in previous project.
Here is a code snippet which shows how you can do it:
Dim outputFile As String = """" & Path.GetTempFileName & """"
Dim batchCommand As String = """C:\Path\To\MyFile.bat"">" & outputFile
Dim cmdProcess As New Process
With cmdProcess
.StartInfo = New ProcessStartInfo("cmd.exe", "/C " & batchCommand)
With .StartInfo
.CreateNoWindow = True
.UseShellExecute = False
End With
.Start()
.WaitForExit()
End With
' This is the output from the batch file.
Dim batchOutput As String = My.Computer.FileSystem.ReadAllText(outputFile)
I have a Process.Start command that I would like to see the output of, but the new window is opening and closing too quickly for me to see anything. Here is the code I have so far that I'm working with:
System.Diagnostics.Process.Start(Environment.GetEnvironmentVariable("VS110COMNTOOLS") & "..\Ide\MSTEST.EXE", "/Testsettings: """ & rwSettings & "" & " /Testcontainer: """ & rwContainer & "" & " /Resultsfile: """ & rwResults & "")
Unfortunately as I try to debug this if I allow this to run it flashes up the window but doesn't let me see what the error is, or if it's running successfully at all. I'm using VS2012 so I might just not be looking at the right view when I'm debugging.
Here is some code taen out of the middle of some logic, so it is not standalone. You can use ProcessStartInfo() and Process() to have more control:
Dim start_info As New ProcessStartInfo("sqlcmd", cmd)
start_info.UseShellExecute = False
start_info.CreateNoWindow = True
start_info.RedirectStandardOutput = True
start_info.RedirectStandardError = True
' Make the process and set its start information.
Dim proc As New Process()
proc.StartInfo = start_info
Dim dt As Date = Now()
' Start the process.
proc.Start()
' Attach to stdout and stderr.
Dim std_out As StreamReader = proc.StandardOutput() ' will not continue until process stops
Dim std_err As StreamReader = proc.StandardError()
' Retrive the results.
Dim sOut As String = std_out.ReadToEnd()
Dim sErr As String = std_err.ReadToEnd()
Initial Problem
I apologize if this issue has been raised and addressed elsewhere; I searched this site, and Google at large without any luck.
I'm trying to write a simple VB.Net Windows Forms Application to allow a user to run the Windows File Compare program (fc.exe) with a very simple GUI ("browse" buttons to select files, checkboxes to select modifiers, and a textbox for the output).
The problem is that whenever I try to read the standard output or error from the process, it immediately stops, and nothing is output. I've verified that the process arguments are correct by setting "createnowindow" to False and not redirecting Output or Errors.
To see if the process is actually running or not, I put a "while" loop after proc.start:
Do While proc.HasExited = False
textbox.AppendText(i & vbNewLine)
i += 1
Loop
If the process runs normally, I get a count up to about 80 or 90. If I do anything at all with the standardoutput or standarderror, the textbox only shows the initial value of "0". By "anything at all", I mean assigning the proc.StandardOutput.ReadToEnd to a variable. If I use proc.StandardOutput.Peek, it returns a -1 and the loop remains at 0.
I've noticed that if I only redirect either Output or Error (but not both), and I enable the process to open a new window, the new window is empty and immediately exits (even if I'm not attempting to read the redirected stream in my code), whereas if neither is redirected, it displays a few pages of results, then exits. I don't know if this is normal, or if the File Compare executable is somehow mixing the Output and Error streams to generate its output, or if something like that is even possible.
I'm extremely new to coding in general (I've been working with VB.net for about a month, and that's the extent of my programming experience), so my I'm aware that my troubleshooting and assumptions may be completely off base, and I appreciate any assistance anyone can provide. As it is, I'm completely floundering, and my inexperience is making it difficult to look for alternatives (for instance, I can't figure out how to correctly handle asynchronous output). For reference, here's my embarrassingly clunky code as it currently stands:
Dim cmdinput As String = """" & file1path & """" & " " & """" & file2path & """"
Dim cmdmods As String = " "
Dim i As Integer = 0
Dim proc As New Process
proc.StartInfo.CreateNoWindow = True
proc.StartInfo.UseShellExecute = False
proc.StartInfo.FileName = "C:\Windows\System32\fc.exe"
proc.StartInfo.Arguments = cmdinput & cmdmods
proc.StartInfo.RedirectStandardOutput = True
proc.StartInfo.RedirectStandardError = True
proc.Start()
proc.StandardOutput.ReadToEnd()
Do While proc.HasExited = False
scanbox.AppendText(i & vbNewLine)
i += 1
Loop
Possible Solution
After Hans Passant pointed out that I should be seeing errors, if nothing else, I messed around with my code and was able to get a result, though a less than optimal one. Instead of running FC.exe directly, I ran CMD.exe. I had tried this before with no luck, but that's because CMD.exe doesn't accept "fc " as process.startinfo.arguments.
I passed the "fc " to cmd.exe with proc.standardinput.writeline(). At this point I was able to read CMD.exe's redirected output. I still have no idea why I can't directly read FC.exe, but this is a pretty good band-aid in the meantime. On the off chance that anyone else feels the need to add a GUI to a perfectly good command-line executable and runs into problems, here's my code:
Public Sub compare()
Dim cmdinput As String = "fc " & """" & file1path & """" & " " & """" & file2path & """"
Dim cmdmods As String = " "
Dim proc As New Process
proc.StartInfo.CreateNoWindow = True
proc.StartInfo.UseShellExecute = False
proc.StartInfo.FileName = "C:\Windows\System32\cmd.exe"
proc.StartInfo.Arguments = cmdinput & cmdmods
proc.StartInfo.RedirectStandardOutput = True
proc.StartInfo.RedirectStandardError = True
proc.StartInfo.RedirectStandardInput = True
proc.Start()
proc.StandardInput.WriteLine(cmdinput)
proc.StandardInput.Close()
scanbox.AppendText(proc.StandardOutput.ReadToEnd)
proc.WaitForExit()
proc.Close()
proc.Dispose()
End Sub
I Greatly appreciate the patience from Hans Passant and Dan Verdolino in offering suggestions to my rambling question. I've been hammering my head against a wall for a week trying to kludge together some way of doing this.
Solution
Instead of running FC.exe directly, I ran CMD.exe. I had tried this before with no luck, but that's because CMD.exe doesn't accept "fc (args)" as process.startinfo.arguments.
I passed the "fc (args)" to cmd.exe with proc.standardinput.writeline(). At this point I was able to read CMD.exe's redirected output. I still have no idea why I can't directly read FC.exe's output or errors, but this is a pretty good band-aid in the meantime. On the off chance that anyone else feels the need to add a GUI to a perfectly good command-line executable and runs into problems, here's my code:
Public Sub compare()
Dim cmdinput As String = "fc " & """" & file1path & """" & " " & """" & file2path & """"
Dim cmdmods As String = " "
Dim proc As New Process
proc.StartInfo.CreateNoWindow = True
proc.StartInfo.UseShellExecute = False
proc.StartInfo.FileName = "C:\Windows\System32\cmd.exe"
proc.StartInfo.Arguments = cmdinput & cmdmods
proc.StartInfo.RedirectStandardOutput = True
proc.StartInfo.RedirectStandardError = True
proc.StartInfo.RedirectStandardInput = True
proc.Start()
proc.StandardInput.WriteLine(cmdinput)
proc.StandardInput.Close()
scanbox.AppendText(proc.StandardOutput.ReadToEnd)
proc.WaitForExit()
proc.Close()
proc.Dispose()
End Sub
Private Delegate Sub InvokeWithString(ByVal text As String)
Public Sub StartFC()
Private psi As ProcessStartInfo
Private cmd As Process
Dim CMDINPUT As String = "fc " & """" & file1path & """" & " " & """" & file2path & """"
Dim FileToHit As String = "c:\windows\system32\fc.exe "
psi = New ProcessStartInfo(FileToHit)
Dim systemencoding As System.Text.Encoding = _
System.Text.Encoding.GetEncoding(Globalization.CultureInfo.CurrentUICulture.TextInfo.OEMCodePage)
With psi
.Arguments = CMDINPUT
.UseShellExecute = False ' Required for redirection
.RedirectStandardError = True
.RedirectStandardOutput = True
.RedirectStandardInput = True
.CreateNoWindow = True
.StandardOutputEncoding = systemencoding
.StandardErrorEncoding = systemencoding
End With
' EnableraisingEvents is required for Exited event
cmd = New Process With {.StartInfo = psi, .EnableRaisingEvents = True}
AddHandler cmd.ErrorDataReceived, AddressOf Async_Data_Received
AddHandler cmd.OutputDataReceived, AddressOf Async_Data_Received
AddHandler cmd.Exited, AddressOf CMD_Exited
cmd.Start()
pID1 = cmd.Id
cmd.BeginOutputReadLine()
cmd.BeginErrorReadLine()
Me.txtInputStringIn.Select() ' textbox where you can send more commands.
End Sub
'This event fires when process exited
Private Sub CMD_Exited(ByVal sender As Object, ByVal e As EventArgs)
'Me.Close()
MessageBox.Show("Process is exited.")
End Sub
'This part calls when Output received
Private Sub Async_Data_Received(ByVal sender As Object, ByVal e As DataReceivedEventArgs)
Me.Invoke(New InvokeWithString(AddressOf Sync_Output), e.Data)
End Sub
Private Sub Sync_Output(ByVal text As String)
'an output textbox will show the output of the command prompt.
txtOutPut.AppendText(text & Environment.NewLine)
txtOutPut.ScrollToCaret()
End Sub