A way to check user input is valid folder name?

[Jaymond Flurrie]

Would there be some easy method (for example regular expression would do the trick, but I'm not fluent with them) to check that user gave me on input box something that I can use as a folder name? I know how to capture the string, but validating is the problem here.

 

[Ralajer]

The below function is a direct way to see if string would be a valid folder name. It tries to create the folder using the provide name in the temp directory if it already exist or was created successfully it returns true.

Function ValidFolderName(folderName As String) As Boolean

    Dim TestName As String
    Dim str As String

    TestName = Environ("Temp") & "\" & folderName
    On Error Resume Next
    str = Dir(TestName, vbDirectory)
    '// To Prevent existing folder from being deleted
    If str <> "" Then
        ValidFolderName = True
        Exit Function
    End If
    '// Try and make a directory with provided name
    MkDir (TestName)
    '// True if directory was created
    ValidFolderName = Dir(TestName, vbDirectory) <> ""
    '// Delete if directory was created to avoid clutter.
    If ValidFolderName Then RmDir TestName
    On Error GoTo 0
End Function

 

[RoryA]

You could use something like this (which I think originally came from XtremeVBTalk):

Public Function IsInvalidFileName(ByVal FileName As String) As Boolean

    Dim re As Object
    Set re = CreateObject("VBScript.RegExp")
    'forbidden characters in file names:
    re.Pattern = "[\\/:\*\?""<>\|]"
    IsInvalidFileName = (re.Execute(FileName).Count > 0)
    Set re = Nothing

End Function

 

[Jaymond Flurrie]

Ralajer's solution seems more for those who wants to understand everything in there, while Rory's is more flexible (if I don't want "a" in the name for some reason, Rory's solution is easier to modify).

Anyway, I think that both are great answers, thanks!