cStdIO Methods Reference

ExecuteCommand

Executes command line program and captures its standard output.

Public Function ExecuteCommand( _
    ByVal CommandLine As String, _
    Optional ByVal TimeoutMs As Long = 10000, _
    Optional ByVal CurrentDirectory As String = "", _
    Optional ByRef exitCode As Long _
) As String

Parameters

Parameter	Type	Default	Description
CommandLine	String	-	Command line to execute (includes program path and arguments)
TimeoutMs	Long	10000	Timeout (milliseconds), default 10 seconds
CurrentDirectory	String	""	Working directory, empty string means use current directory
exitCode	Long	-	Output parameter, process exit code

Return Value

• Success - Returns command line standard output text
• Failure - Returns error description string (starting with "STDIO ERROR:")

Error Codes

Error codes returned via exitCode parameter:

Error Code	Constant	Description
0	ERROR_OK	Execution successful
1	ERROR_CREATE_PIPE	Failed to create pipe
2	ERROR_DUPLICATE_HANDLE	Failed to duplicate handle
3	ERROR_CREATE_PROCESS	Failed to create process
4	ERROR_READ_OUTPUT	Failed to read output
5	ERROR_PROCESS_TIMEOUT	Execution timeout

Examples

Basic Usage

Dim StdIO As New cStdIO
Dim Output As String
Dim ExitCode As Long

Output = StdIO.ExecuteCommand("echo Hello World", 5000, "", ExitCode)
Debug.Print Output  ' Output: Hello World

Command with Arguments

Dim StdIO As New cStdIO
Dim Output As String
Dim ExitCode As Long

' Execute command with arguments
Output = StdIO.ExecuteCommand( _
    "findstr /s /i ""keyword"" *.txt", _
    10000, _
    "C:\\Documents", _
    ExitCode _
)

If ExitCode = 0 Then
    Debug.Print "Found match: " & Output
Else
    Debug.Print "No match found"
End If

Complete Error Handling

Private Sub ExecuteSafe()
    Dim StdIO As New cStdIO
    Dim Result As String
    Dim ExitCode As Long
    
    On Error GoTo ErrorHandler
    
    Result = StdIO.ExecuteCommand("mycommand.exe", 5000, "", ExitCode)
    
    ' Check if returns error string
    If Left$(Result, 11) = "STDIO ERROR" Then
        MsgBox "Execution error: " & Result, vbCritical
        Exit Sub
    End If
    
    ' Check exit code
    Select Case ExitCode
        Case 0
            Debug.Print "Execution successful: " & Result
        Case 1
            Debug.Print "Command returned error: " & Result
        Case 5
            MsgBox "Execution timeout!", vbExclamation
        Case Else
            Debug.Print "Unknown error, exit code: " & ExitCode
    End Select
    
    Exit Sub
    
ErrorHandler:
    MsgBox "Exception occurred: " & Err.Description, vbCritical
End Sub

Specify Working Directory

Private Sub RunInDirectory()
    Dim StdIO As New cStdIO
    Dim Output As String
    Dim ExitCode As Long
    
    ' Execute git command in specified directory
    Output = StdIO.ExecuteCommand( _
        "git log --oneline -10", _
        10000, _
        "D:\\Projects\\MyRepo", _
        ExitCode _
    )
    
    If ExitCode = 0 Then
        txtLog.Text = Output
    End If
End Sub