How to get the handle of a running application using vb6

Option Compare Text: Option Explicit: Option Base 0
 
Private Type PROCESSENTRY32
  size As Long
  usage As Long
  processId As Long
  defaultHeapId As Long
  moduleId As Long
  cntThreads As Long
  parentProcessId As Long
  classBase As Long
  flags As Long
  exeFile As String * 500
End Type
 
Private Const INVALID_HANDLE_VALUE As Long = -1
Private Const TH32CS_SNAPPROCESS As Long = 2
 
Private Declare Function kCloseHandle Lib "kernel32.dll" Alias "CloseHandle" (ByVal hObject As Long) As Long
Private Declare Function kCreateToolhelpSnapshot Lib "kernel32.dll" Alias "CreateToolhelp32Snapshot" (ByVal flags As Long, ByVal processId As Long) As Long
Private Declare Function kProcessFirst Lib "kernel32.dll" Alias "Process32First" (ByVal hSnapshot As Long, processEntry As PROCESSENTRY32) As Long
Private Declare Function kProcessNext Lib "kernel32.dll" Alias "Process32Next" (ByVal hSnapshot As Long, processEntry As PROCESSENTRY32) As Long
 
Public Sub main(): Call printProcessNames: End Sub
 
Public Sub printProcessNames()
Dim processes() As String, i As Long
  If getProcessNames(processes) Then
    For i = LBound(processes) To UBound(processes)
      Debug.Print i, processes(i)
    Next i
  End If
End Sub
 
Private Function getProcessNames(ByRef processes() As String, Optional ByVal sortResults As Boolean = False) As Long
Dim retVal As Long, hSnapshot As Long, processEntry As PROCESSENTRY32
  Let hSnapshot = kCreateToolhelpSnapshot(TH32CS_SNAPPROCESS, 0)
  If hSnapshot = INVALID_HANDLE_VALUE Then
    Let retVal = 0
  Else: Let processEntry.size = Len(processEntry)
    If kProcessFirst(hSnapshot, processEntry) Then
      ReDim processes(0 To 0): Do: Call ensureCapacityString(processes, retVal)
        Let processes(inc(retVal)) = getNullTerminatedString(processEntry.exeFile)
      Loop While kProcessNext(hSnapshot, processEntry)
      If retVal <= UBound(processes) Then ReDim Preserve processes(0 To retVal - 1)
    Else: Let retVal = 0
    End If: Call kCloseHandle(hSnapshot)
    'If sortResults Then Call shellSortString(processes)
  End If: Let getProcessNames = retVal
End Function
 
Private Sub ensureCapacityString(ByRef vector() As String, ByVal size As Long, Optional ByVal chunk As Long = 256)
Dim oldCapacity As Long, newCapacity As Long
  Let oldCapacity = 1 - LBound(vector) + UBound(vector)
  Let newCapacity = IIf(size And 255 = 0, size, 256 * (1 + size \ 256))
  If oldCapacity < newCapacity Then ReDim Preserve vector(LBound(vector) To LBound(vector) - 1 + newCapacity)
End Sub
 
Private Function getNullTerminatedString(ByRef str As String) As String
Dim i As Long
  Let i = InStr(str, vbNullChar)
  Let getNullTerminatedString = Left$(str, IIf(i = 0, Len(str), i - 1))
End Function
 
Private Function inc(ByRef i As Long) As Long: Let inc = i: Let i = i + 1: End Function

                                              

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'Remark: If you're using VB4 or VB5, you should first uncomment
' the Replace function (on the end of the code)
 
'In a form
Private Sub Form_Load()
    'Code submitted by Roger Taylor
    'enumerate all the different explorer.exe processes
    GetProcesses "explorer.exe"
End Sub
 
'In a module
 
Public Declare Function GetProcessMemoryInfo Lib "PSAPI.DLL" (ByVal hProcess As Long, ppsmemCounters As PROCESS_MEMORY_COUNTERS, ByVal cb As Long) As Long
Public Declare Function Process32First Lib "kernel32" (ByVal hSnapshot As Long, lppe As PROCESSENTRY32) As Long
Public Declare Function Process32Next Lib "kernel32" (ByVal hSnapshot As Long, lppe As PROCESSENTRY32) As Long
Public Declare Function CloseHandle Lib "Kernel32.dll" (ByVal Handle As Long) As Long
Public Declare Function OpenProcess Lib "Kernel32.dll" (ByVal dwDesiredAccessas As Long, ByVal bInheritHandle As Long, ByVal dwProcId As Long) As Long
Public Declare Function EnumProcesses Lib "PSAPI.DLL" (ByRef lpidProcess As Long, ByVal cb As Long, ByRef cbNeeded As Long) As Long
Public Declare Function GetModuleFileNameExA Lib "PSAPI.DLL" (ByVal hProcess As Long, ByVal hModule As Long, ByVal ModuleName As String, ByVal nSize As Long) As Long
Public Declare Function EnumProcessModules Lib "PSAPI.DLL" (ByVal hProcess As Long, ByRef lphModule As Long, ByVal cb As Long, ByRef cbNeeded As Long) As Long
Public Declare Function CreateToolhelp32Snapshot Lib "kernel32" (ByVal dwFlags As Long, ByVal th32ProcessID As Long) As Long
Public Declare Function GetVersionExA Lib "kernel32" (lpVersionInformation As OSVERSIONINFO) As Integer
Public Declare Function SetTimer Lib "user32" (ByVal hwnd As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long) As Long
Public Declare Function KillTimer Lib "user32" (ByVal hwnd As Long, ByVal nIDEvent As Long) As Long
Public Declare Sub GlobalMemoryStatus Lib "kernel32" (lpBuffer As MEMORYSTATUS)
 
 
 
Public Const PROCESS_QUERY_INFORMATION = 1024
Public Const PROCESS_VM_READ = 16
Public Const MAX_PATH = 260
Public Const STANDARD_RIGHTS_REQUIRED = &HF0000
Public Const SYNCHRONIZE = &H100000
Public Const PROCESS_ALL_ACCESS = &H1F0FFF
Public Const TH32CS_SNAPPROCESS = &H2&
Public Const hNull = 0
Public Const WIN95_System_Found = 1
Public Const WINNT_System_Found = 2
Public Const Default_Log_Size = 10000000
Public Const Default_Log_Days = 0
Public Const SPECIFIC_RIGHTS_ALL = &HFFFF
Public Const STANDARD_RIGHTS_ALL = &H1F0000
 
 
Type MEMORYSTATUS
    dwLength As Long
    dwMemoryLoad As Long
    dwTotalPhys As Long
    dwAvailPhys As Long
    dwTotalPageFile As Long
    dwAvailPageFile As Long
    dwTotalVirtual As Long
    dwAvailVirtual As Long
End Type
 
 
Type PROCESS_MEMORY_COUNTERS
    cb As Long
    PageFaultCount As Long
    PeakWorkingSetSize As Long
    WorkingSetSize As Long
    QuotaPeakPagedPoolUsage As Long
    QuotaPagedPoolUsage As Long
    QuotaPeakNonPagedPoolUsage As Long
    QuotaNonPagedPoolUsage As Long
    PagefileUsage As Long
    PeakPagefileUsage As Long
End Type
 
 
Public Type PROCESSENTRY32
    dwSize As Long
    cntUsage As Long
    th32ProcessID As Long ' This process
    th32DefaultHeapID As Long
    th32ModuleID As Long ' Associated exe
    cntThreads As Long
    th32ParentProcessID As Long ' This process's parent process
    pcPriClassBase As Long ' Base priority of process threads
    dwFlags As Long
    szExeFile As String * 260 ' MAX_PATH
    End Type
 
 
Public Type OSVERSIONINFO
    dwOSVersionInfoSize As Long
    dwMajorVersion As Long
    dwMinorVersion As Long
    dwBuildNumber As Long
    dwPlatformId As Long '1 = Windows 95.
    '2 = Windows NT
    szCSDVersion As String * 128
End Type
 
 
Public Function GetProcesses(ByVal EXEName As String)
 
    Dim booResult As Boolean
    Dim lngLength As Long
    Dim lngProcessID As Long
    Dim strProcessName As String
    Dim lngSnapHwnd As Long
    Dim udtProcEntry As PROCESSENTRY32
    Dim lngCBSize As Long 'Specifies the size, In bytes, of the lpidProcess array
    Dim lngCBSizeReturned As Long 'Receives the number of bytes returned
    Dim lngNumElements As Long
    Dim lngProcessIDs() As Long
    Dim lngCBSize2 As Long
    Dim lngModules(1 To 200) As Long
    Dim lngReturn As Long
    Dim strModuleName As String
    Dim lngSize As Long
    Dim lngHwndProcess As Long
    Dim lngLoop As Long
    Dim b As Long
    Dim c As Long
    Dim e As Long
    Dim d As Long
    Dim pmc As PROCESS_MEMORY_COUNTERS
    Dim lret As Long
    Dim strProcName2 As String
    Dim strProcName As String
 
    'Turn on Error handler
    On Error GoTo Error_handler
 
   booResult = False
 
    EXEName = UCase$(Trim$(EXEName))
    lngLength = Len(EXEName)
 
    'ProcessInfo.bolRunning = False
 
    Select Case getVersion()
        'I'm not bothered about windows 95/98 becasue this class probably wont be used on it anyway.
        Case WIN95_System_Found 'Windows 95/98
 
        Case WINNT_System_Found 'Windows NT
 
            lngCBSize = 8 ' Really needs To be 16, but Loop will increment prior to calling API
            lngCBSizeReturned = 96
 
            Do While lngCBSize <= lngCBSizeReturned
                DoEvents
                'Increment Size
                lngCBSize = lngCBSize * 2
                'Allocate Memory for Array
                ReDim lngProcessIDs(lngCBSize / 4) As Long
                'Get Process ID's
                lngReturn = EnumProcesses(lngProcessIDs(1), lngCBSize, lngCBSizeReturned)
            Loop
 
            'Count number of processes returned
            lngNumElements = lngCBSizeReturned / 4
            'Loop thru each process
 
            For lngLoop = 1 To lngNumElements
            DoEvents
 
            'Get a handle to the Process and Open
            lngHwndProcess = OpenProcess(PROCESS_QUERY_INFORMATION Or PROCESS_VM_READ, 0, lngProcessIDs(lngLoop))
 
            If lngHwndProcess <> 0 Then
                'Get an array of the module handles for the specified process
                lngReturn = EnumProcessModules(lngHwndProcess, lngModules(1), 200, lngCBSize2)
 
                'If the Module Array is retrieved, Get the ModuleFileName
                If lngReturn <> 0 Then
 
                    'Buffer with spaces first to allocate memory for byte array
                    strModuleName = Space(MAX_PATH)
 
                    'Must be set prior to calling API
                    lngSize = 500
 
                    'Get Process Name
                    lngReturn = GetModuleFileNameExA(lngHwndProcess, lngModules(1), strModuleName, lngSize)
 
                    'Remove trailing spaces
                    strProcessName = Left(strModuleName, lngReturn)
 
                    'Check for Matching Upper case result
                    strProcessName = UCase$(Trim$(strProcessName))
 
                    strProcName2 = GetElement(Trim(Replace(strProcessName, Chr$(0), "")), "\", 0, 0, GetNumElements(Trim(Replace(strProcessName, Chr$(0), "")), "\") - 1)
 
                    If strProcName2 = EXEName Then
 
                        'Get the Site of the Memory Structure
                        pmc.cb = LenB(pmc)
 
                           lret = GetProcessMemoryInfo(lngHwndProcess, pmc, pmc.cb)
 
                            Debug.Print EXEName & "::" & CStr(pmc.WorkingSetSize / 1024)
 
                    End If
                End If
            End If
            'Close the handle to this process
            lngReturn = CloseHandle(lngHwndProcess)
            DoEvents
        Next
 
    End Select
 
IsProcessRunning_Exit:
 
'Exit early to avoid error handler
Exit Function
Error_handler:
    Err.Raise Err, Err.Source, "ProcessInfo", Error
    Resume Next
End Function
 
 
Private Function getVersion() As Long
 
    Dim osinfo As OSVERSIONINFO
    Dim retvalue As Integer
 
    osinfo.dwOSVersionInfoSize = 148
    osinfo.szCSDVersion = Space$(128)
    retvalue = GetVersionExA(osinfo)
    getVersion = osinfo.dwPlatformId
 
End Function
 
 
Private Function StrZToStr(s As String) As String
    StrZToStr = Left$(s, Len(s) - 1)
End Function
 
 
 
Public Function GetElement(ByVal strList As String, ByVal strDelimiter As String, ByVal lngNumColumns As Long, ByVal lngRow As Long, ByVal lngColumn As Long) As String
 
    Dim lngCounter As Long
 
    ' Append delimiter text to the end of the list as a terminator.
    strList = strList & strDelimiter
 
    ' Calculate the offset for the item required based on the number of columns the list
    ' 'strList' has i.e. 'lngNumColumns' and from which row the element is to be
    ' selected i.e. 'lngRow'.
    lngColumn = IIf(lngRow = 0, lngColumn, (lngRow * lngNumColumns) + lngColumn)
 
    ' Search for the 'lngColumn' item from the list 'strList'.
    For lngCounter = 0 To lngColumn - 1
 
        ' Remove each item from the list.
        strList = Mid$(strList, InStr(strList, strDelimiter) + Len(strDelimiter), Len(strList))
 
        ' If list becomes empty before 'lngColumn' is found then just
        ' return an empty string.
        If Len(strList) = 0 Then
            GetElement = ""
            Exit Function
        End If
 
    Next lngCounter
 
    ' Return the sought list element.
    GetElement = Left$(strList, InStr(strList, strDelimiter) - 1)
 
End Function
 
 
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'Function GetNumElements (ByVal strList As String,
'                         ByVal strDelimiter As String)
'                         As Integer
'
'  strList      = The element list.
'  strDelimiter = The delimiter by which the elements in
'                 'strList' are seperated.
'
'  The function returns an integer which is the count of the
'  number of elements in 'strList'.
'
'  Author: Roger Taylor
'
'  Date:26/12/1998
'
'  Additional Information:
'
'  Revision History:
'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 
Public Function GetNumElements(ByVal strList As String, ByVal strDelimiter As String) As Integer
 
    Dim intElementCount As Integer
 
    ' If no elements in the list 'strList' then just return 0.
    If Len(strList) = 0 Then
        GetNumElements = 0
        Exit Function
    End If
 
    ' Append delimiter text to the end of the list as a terminator.
    strList = strList & strDelimiter
 
    ' Count the number of elements in 'strlist'
    While InStr(strList, strDelimiter) > 0
        intElementCount = intElementCount + 1
        strList = Mid$(strList, InStr(strList, strDelimiter) + 1, Len(strList))
    Wend
 
    ' Return the number of elements in 'strList'.
    GetNumElements = intElementCount
 
End Function
 
 
'If you're using VB4 or VB5, uncomment the following function:
'Function Replace(sInput As String, WhatToReplace As String, ReplaceWith As String) As String
    'Dim Ret As Long
    'Replace = sInput
    'Ret = -Len(ReplaceWith) + 1
    'Do
        'Ret = InStr(Ret + Len(ReplaceWith), Replace, WhatToReplace, vbTextCompare)
        'If Ret = 0 Then Exit Do
        'Replace = Left$(Replace, Ret - 1) + ReplaceWith + Right$(Replace, Len(Replace) - Ret - Len(WhatToReplace) + 1)
    'Loop
'End Function
                                              

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