Getting the Returnvalue of an application started from VB

[Patzer]

Hi out there,

I created a VB-program that calls another application via shellexecute.
That app is a backup program, that gets commandline parameters from my VB-program.

Now sometimes the backup program crashes, and the backup files are not correctly finished or incomplete.

The backup program delivers a returnvalue that is 0 when it completes the backup successfully, if the value is <> 0 the backup failed.

The returnvalue of Shellexecute AFAIK delivers only Information about the execution of the command, so it does not help.
But then how can I get the returnvalue of the application in VB?

[Shaikh.Riyaz.a]

You can use SendMessage API from your backup program to notify the main app.

[Patzer]

Hi Shaikh.Riyaz.a,

seems I did not make it clear:

The Backup Program is a 3rd Party tool. We bought it.

My program calls that backup program with user-specific commandline-parameters

AFAIK sendmessage could be used if I could change the code of the backup Program, or am I missing something?

[dglienna]

Here's how to trap the return code...

Option Explicit

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, _
ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

Private Const SW_SHOWNORMAL As Long = 1
Private Const SW_HIDE As Long = 0

Private Declare Function GetSystemDirectory Lib "kernel32" Alias "GetSystemDirectoryA" (ByVal lpBuffer As String, ByVal nSize As Long) As Long

Dim sSave As String, Ret As Long

Private Sub Form_Load()
    'KPD-Team 1998
    'URL: http://www.allapi.net/
    'E-Mail: [email protected]
    Dim sSave As String, Ret As Long
    'Create a buffer
    sSave = Space(255)
    'Get the system directory
    Ret = GetSystemDirectory(sSave, 255)
    'Remove all unnecessary chr$(0)'s
    sSave = Left$(sSave, Ret)
End Sub

Private Sub Command1_Click()
   Dim d As Long
   d = ShellExecute(Me.hwnd, "Open", sSave & "CMD.exe", " /c dir c: > c:\Myfile.txt", "c:\", SW_SHOWNORMAL)
   MsgBox d
End Sub

[Shaikh.Riyaz.a]

The Backup Program is a 3rd Party tool. We bought it.

My program calls that backup program with user-specific commandline-parameters

Then right now in what format does it return the success or failure of its own? I mean how come you know that it ran successfully?

[dglienna]

It doesn't crash?

[Mark Agius]

If you don't want to use On Error Goto YourErrorCode
to check for crash.
d will return the following value.

 Private Sub Command1_Click()
   Dim d As Long
   d = ShellExecute(Me.hwnd, "Open", sSave & "CMD.exe", " /c dir c: > c:\Myfile.txt", "c:\", SW_SHOWNORMAL)
   MsgBox d
   ' The return values (d=...) are;
   ' <=32 ' = Some type of error.
   ' > 32 ' = OK. No error
   '  = 0 ' = Operating system is out of memory.
   '  = 2 ' = File (CMD.exe) was not found.
   '  =42 ' = Found and ran without any errors.
   ' See URL; http://allapi.mentalis.org/apilist/ShellExecute.shtml
   ' for more information.
End Sub