How to tell if a VB exe is running

[Patrice Bourdages]

I created a VB 6 app that multiple user run on their workstation. The installation
package is on the production server in a place called \\WhatEverServer\Software\MySoftware.
In that spot, there is the executable (which I recreate "recompile" from time to time) and the
installation package.

I need to be able to update the PC's because of minor changes et whatever. I'll probably
create an executable that will check if the application is currently running and if not, copy the
new executable file from the server to the PC.

• How to find out if the application is currently running?
• What kind of code do I need to copy the updated
  executable from the \\WhatEverServer spot to the PC?

TIA for any advice and/or sample code

[paulw]

Saw no replies and took pity...

I am sure that I have something to do this at home - I will revert to you on Monday.

Paul

[Patrice Bourdages]

Thanks ... for the moment... At least one reply

I don't know the answer, but this is the question I had and I'm having trouble posting a new thread so I am replying in order to reintroduce the question.

On startup of my app I want to see if there is another instance already running. Any help is appreciated.

[Patrice Bourdages]

I've been searching in a bunch of VB sites and found only one reference (16 bits version for VB3 or 4). There must be something out there somewhere...

Awaiting the comeback from PaulW. Hope he'll be succesfull in retreiving what we need.

[vbuser1976]

This probably has nothing to do with what you said but ,hey, at least I'm thinking :-). If the workstations the application is supposedly running is NT or 2000, then do Ctrl-Alt-Del to open task manager. That will tell you the status of all/any applications running at that time on that workstation.

Hope this helps.

[Patrice Bourdages]

Ok... I see your point (I think ). Then how do we integrate that into a VB app? Worse, how to make sure that will work on Win9x flavors?

I'm lost...

Back to square two (we at least have something going)

[Patrice Bourdages]

I forgot... If you implied that the user could determine if the apps is running... forget it... They don't know.. Even if I explain them what to look for.

[Serge]

Do your users run only one instance of your application? I mean do you have your EXE somewhere on the LAN where everyone has access to? Or each user has it's own copy?

If they use the LAN version, then you can do something I've done some time ago:

Instead of having an EXE on the LAN, have a batch file which the user will run. This batch file will copy your EXE from the LAN to their local drive and execute it. This way, you can always upgrade your EXE without being worrying that someone is running it. As far as a user concerned, as soon as he/she rerun the batch file, the new version will be copied.

Just a thought,

[marnitzg]

Originally posted by help<
I don't know the answer, but this is the question I had and I'm having trouble posting a new thread so I am replying in order to reintroduce the question.

On startup of my app I want to see if there is another instance already running. Any help is appreciated.

If App.PrevInstance = True then
    Unload Me
End If

Now to tthe other problem. What you could do is just try and update the file. If the program is running you will get an error message that says something to the effect of "sharing violation".

[tclere]

1. If you try to copy the file to the workstation, you will get an error if the file is in use. Trap this error and you know which workstations are currently using the application.

2. The App.PrevInstance will only indicate if another instance of this application is running. You can't use it to detect other applications.

3. To get a list of all applications/proceses currently running, start a new project, add a command button and a list box to Form1.

I think that I found this code here. You can modify it to suit your needs (i.e. find a specific exe file running)

Private Declare Function GetWindow Lib "user32" (ByVal hwnd As Long, ByVal wCmd As Long) As Long
Private Declare Function GetParent Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As Long) As Long
Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long

Const GW_HWNDFIRST = 0
Const GW_HWNDNEXT = 2

Private Sub Command1_Click()
    LoadTaskList
End Sub

Sub LoadTaskList()

    Dim CurrWnd As Long
    Dim Length As Long
    Dim TaskName As String
    Dim Parent As Long

    List1.Clear
    CurrWnd = GetWindow(Form1.hwnd, GW_HWNDFIRST)

    While CurrWnd <> 0
        Parent = GetParent(CurrWnd)
        Length = GetWindowTextLength(CurrWnd)
        TaskName = Space$(Length + 1)
        Length = GetWindowText(CurrWnd, TaskName, Length + 1)
        TaskName = Left$(TaskName, Len(TaskName) - 1)
        
        If Length > 0 Then
            If TaskName <> Me.Caption Then
                List1.AddItem TaskName
            End If
        End If

        CurrWnd = GetWindow(CurrWnd, GW_HWNDNEXT)
        DoEvents

    Wend
End Sub

If you are running the install/update program from the workstation just use the FileCopy command;

FileCopy "\\WhatEverServer\my.exe" "C:\my.exe"



[Edited by tclere on 10-31-2000 at 03:38 PM]

[marnitzg]

1. help< asked about a previous instance
2. That was my idea!!!!!!!!!!!!!!!!!!!!!

[Aaron Young]

I did something very similar a year or so ago for an internal system I'd written for the company I work for. What I did was create an Update EXE which is passed the Current EXE and New EXE files and paths, it then copies the new one from the specified location over the old one and then runs it. then all I do is check the EXE dates within my application if there is a newer one in the remote location I call the Update EXE, i.e.
Code for Update.exe

'---------------------------------------------------
'            modUpdate (modUpdate.bas)
'
'    Copies a File From Source to Destination
' If successfull, the Destination File is Launched.
'
'     Written By Aaron Young, September 1999
'---------------------------------------------------
'
' Last Modified: September 9th 1999
' By Aaron Young.
'
Option Explicit

Sub Main()
    Dim sSrc As String
    Dim sDst As String
    Dim tTimer As Single
    tTimer = Timer
    While Timer - tTimer < 2
        DoEvents
    Wend
    On Error GoTo UpdateError
    'Extract Source and Destination Files from the Command Line
    sSrc = Left(Command, InStr(Command, ",") - 1)
    sDst = Mid(Command, Len(sSrc) + 2)
    FileCopy sSrc, sDst
    MsgBox "File Successfully Updated", vbInformation + vbOKOnly, "Update"
    'Start the New File
    Shell sDst, vbNormalFocus
UpdateError:
    If Err Then MsgBox "Source: " & sSrc & vbCrLf & "Destination: " & sDst & vbCrLf & vbLf & Err.Description, vbCritical + vbOKOnly, "Error"
End Sub

Example usage in main app:

    If FileDateTime(App.Path & "\" & App.EXEName & ".EXE") < FileDateTime(sUpdatePath & App.EXEName & ".EXE") Then
        If MsgBox("There is an Newer Version of this Application Available for Download" & vbCrLf & "Update?", vbQuestion + vbYesNo, "Update") = vbYes Then
            Shell sUpdatePath & "\Update.exe " & sUpdatePath & App.EXEName & ".EXE" & "," & App.Path & "\" & App.EXEName & ".EXE", vbNormalFocus
            End
        End If
    End If

[Peterson]

Use the API command "GetModuleHandle" and supply the module's name, where module name = FILENAME if the executable name is FILENAME.EXE.

Microsoft has a bunch of pages on API's so you can search the knowledge base their. Also. search http://www.northernlight.com for "getmodulehandle AND API", and you should get a lot of hits. You will have to declare the kernel32 api file in a .bas file attached to your code.

-lp

[Patrice Bourdages]

Thanks to all you responded to this post.

Really appreciate the help provided by all.

Keep up the posting, newbie like me will continue to learn and perhaps one day, I'll be able to help others like you did here.