Get Name List of All Open Workbook Files

[Excel Fox]

If you to check if a particular file you are looking for is currently open, use this function

Function IsBookOpen(strNameOfFile As String) As Boolean
    Dim wbk As Workbook
    
    For Each wbk In Application.Workbooks
        If InStr(1, wbk.Name, strNameOfFile) Then
            IsBookOpen = True: Exit For
        End If
    Next wbk
    
End Function

and call it like this

IsBookOpen "MyBook.xlsx"

If you want a list of all open workbooks, try modifying by taking out the if condition and printing out the names of each workbook like for example

Msgbox wbk.Name