Force EOL to CRLF on Windows with this Visual Basic Script.

force_crlf.vbs

'Define the list of accepted file extensions
Set extensions = New List
extensions.Add( "h" )
extensions.Add( "hpp" )
extensions.Add( "cpp" )
extensions.Add( "txt" )
extensions.Add( "md" )
extensions.Add( "bat" )
extensions.Add( "cmd" )
extensions.Add( "ps1" )
extensions.Add( "gitignore" )
extensions.Add( "in" )
extensions.Add( "xml" )
extensions.Add( "" ) 'file without an extension should be converted to CRLF.

Set allfiles = GetFilesRecursive(GetScriptDirectory())
Dim file
For Each file In allfiles.GetArray
  If file <> GetCurrentVbsFile() Then 'Skip this is our running script file
    Dim extension
    extension = GetFileExtension(file)
    If ListContains(extensions, extension) Then
      WScript.Echo "file:    " & file
      ForceCRLFLineEnddings file
    Else
      WScript.Echo "skipped: " & file
    End If
  Else
    WScript.Echo "skipped: " & file
  End If
Next


'********************************************************************
'                       Function definitions
'********************************************************************

' Read a file and store the content to a string
Function ReadFile(path)
  Const ForReading = 1
  Dim fso, f
  Set fso = CreateObject("Scripting.FileSystemObject")
  'WScript.Echo "ReadFile(): " & path
  Set f = fso.OpenTextFile(path, ForReading) 'false and -1 is required to allow opening a text file which is not ASCII but unicode.
  ReadFile = f.ReadAll
  f.Close
  Set f= Nothing 
  Set fso = Nothing 
End Function

' Write a string to a file
Function WriteFile(path, text)
  Const ForWriting = 2
  Dim fso, f
  Set fso = CreateObject("Scripting.FileSystemObject")
  'WScript.Echo "WriteFile(): " & path
  Set f = fso.OpenTextFile(path, ForWriting)
  f.Write text
  f.Close
  Set f= Nothing 
  Set fso = Nothing 
End Function

' Replace all EOL characters in a string by CRLF
Function ForceCRLFLineEnddings(path)
  CR = chr(13)
  LF = chr(10)
  content = ReadFile(path)
  content2 = replace(content, LF, CR & LF)
  content3 = replace(content2, CR & CR & LF, CR & LF)
  If content <> content3 Then
    WriteFile path, content3
  End If
End Function

' Returns true If obj is found within myList
Function ListContains(myList, obj)
  Dim element
  ListContains = false
  If myList.HasElements Then
    For Each element In myList.GetArray
      'WScript.Echo "element=" & element & "   obj=" & obj
      If element = obj Then
        ListContains = true
      End If
    Next
  End If
End Function

' Returns the file extension of the given path
Function GetFileExtension(path)
  Set objFSO = CreateObject("Scripting.FileSystemObject")
  GetFileExtension = objFSO.getextensionname(path)
  Set objFSO = Nothing 
End Function

' Get the path of the current running VBS file.
Function GetCurrentVbsFile()
  GetCurrentVbsFile = Wscript.ScriptFullName
End Function

' Get the directory of the current running VBS file.
Function GetScriptDirectory()
  GetScriptDirectory = ParentFolder(GetCurrentVbsFile())
End Function

' Returns the name of the parent folder of the given path
Function ParentFolderName(ByVal path)' As String
  vArray = Split(path, "\")
  size = UBound(vArray)
  ParentFolder = vArray(size - 1)
End Function

' Returns the path of the parent folder of the given path
Function ParentFolder(ByVal path)' As String
  Set objFSO = CreateObject("Scripting.FileSystemObject")
  Set objFile = objFSO.GetFile(path) 
  sName = objFile.Name 
  sPath = objFile.Path 
  ParentFolder = Left(sPath, Len(sPath)-Len(sName)-1) 
  Set objFile = Nothing 
  Set objFSO = Nothing 
End Function

' Get the list of files within the given directory path.
' Note: the Function is not recursive and does not returns the list of directories within the given path.
Function GetFiles(path)
  Set objFSO = CreateObject("Scripting.FileSystemObject")
  Set objFolder = objFSO.GetFolder(path) 
  
  Set GetFiles = New List
  
  'Get all files in given directory
  Set colFiles = objFolder.Files
  For Each objFile in colFiles
    GetFiles.Add( objFile.Path )
  Next
  Set colFiles = nothing
  
  Set objFolder = Nothing 
  Set objFSO = Nothing 
End Function

' Get the list of directories within the given directory path.
' Note: the Function is not recursive.
Function GetSubFolders(path)
  Set objFSO = CreateObject("Scripting.FileSystemObject")
  Set objFolder = objFSO.GetFolder(path) 
  
  Set GetSubFolders = New List
  
  'Get all files in given directory
  Set colFolders = objFolder.SubFolders
  For Each objFolder in colFolders
    GetSubFolders.Add( objFolder.Path )
  Next
  Set colFolders = nothing
  
  Set objFolder = Nothing 
  Set objFSO = Nothing 
End Function

' Get the list of files within the given directory path.
' Note: the Function is recursive.
Function GetFilesRecursive(path)
  Set objFSO = CreateObject("Scripting.FileSystemObject")
  Set objFolder = objFSO.GetFolder(path) 
  
  Set GetFilesRecursive = New List
  
  'Get all files in the given directory
  Set files = GetFiles(path)
  If files.HasElements Then
    For Each element In files.GetArray
      GetFilesRecursive.Add( element )
    Next
  End If
  Set files = nothing
  
'Get all subfolders in the given directory
  Set subfolders = GetSubFolders(path)
  If subfolders.HasElements Then
    For Each folderPath In subfolders.GetArray
      'Get files of the current subfolder
      'WScript.Echo "folderPath=" & folderPath
      Set subfiles = GetFilesRecursive(folderPath)
      If subfiles.HasElements Then
        For Each subSilePath In subfiles.GetArray
          GetFilesRecursive.Add( subSilePath )
        Next
      End If
      Set subfiles = nothing
    Next
  End If
  Set subfolders = nothing
  
  Set objFolder = Nothing 
  Set objFSO = Nothing 
End Function

' List class definition.
' Disclaimer: I am not the author of this class.
' Reference: https://stackoverflow.com/questions/13585660/lists-in-vbscript
Class List
  Private mArray
  
  Private Sub Class_Initialize()
    mArray = Empty
  End Sub
  
' Appends the specified element to the end of this list.
  Public Sub Add(element)
    If IsEmpty(mArray) Then
      ReDim mArray(0)
      mArray(0) = element
    Else
      If mArray(UBound(mArray)) <> Empty Then
        ReDim Preserve mArray(UBound(mArray)+1)        
      End If
      mArray(UBound(mArray)) = element
    End If
  End Sub
  
'  Removes the element at the specified position in this list.
  Public Sub Remove(index)
    ReDim newArray(0)
    For Each atom In mArray
      If atom <> mArray(index) Then
        If newArray(UBound(newArray)) <> Empty Then
          ReDim Preserve newArray(UBound(newArray)+1)
        End If
        newArray(UBound(newArray)) = atom
      End If
    Next
    mArray = newArray
  End Sub
  
' Returns the number of elements in this list.
  Public Function Size
    Size = UBound(mArray)+1
  End Function
  
' Returns the element at the specified position in this list.
  Public Function GetItem(index)
    GetItem = mArray(index)
  End Function
  
' Removes all of the elements from this list.
  Public Sub Clear
    mArray = Empty
  End Sub
  
' Returns true If this list contains elements.
  Public Function HasElements
    HasElements = Not IsEmpty(mArray)
  End Function
  
  Public Function GetIterator
    Set iterator = New ArrayIterator
    iterator.SetArray = mArray
    GetIterator = iterator
  End Function
  
  Public Function GetArray
    GetArray = mArray
  End Function
  
End Class

' ArrayIterator class definition.
' Disclaimer: I am not the author of this class.
' Reference: https://stackoverflow.com/questions/13585660/lists-in-vbscript
Class ArrayIterator
  Private mArray
  Private mCursor  
  
  Private Sub Class_Initialize()
    mCursor = 0
  End Sub
  
  Public Property Let SetArray(array)
    mArray = array    
  End Property
  
  Public Function HasNext
    HasNext = (mCursor < UBound(mArray)+1)
  End Function
  
  Public Function GetNext
    GetNext = mArray(mCursor)
    mCursor = mCursor + 1
  End Function
End Class

To facilitate the use of the script, one can create a batch file along the vbs file (using the same name) for quickly launching the script:

force_crlf.bat:

@echo off
cscript //nologo "%~dpn0.vbs"
pause