Need help with Regex or wildcard-like functionality

[WildByDesign]

I need help with creating a function that I can pass a path to and have it confirm whether it's the root of the drive or not.

Example:

$sDriveC = "C:"
$sDriveD = "D:"
$sDriveE = "E:"
$sDriveR = "R:"
$sNotRoot = "C:\Example"

If IsRootDrive($sDriveC) Then ConsoleWrite("This is root drive." & @CRLF)
If Not IsRootDrive($sNotRoot) Then ConsoleWrite("This is not a root drive." & @CRLF)

Func IsRootDrive($sDrive)
    ;
    ; something like:
    ; "*:"
    ; needs to confirm 2 characters
    ; first character being a single drive letter
    ; second character being a colon
    ; there is no backslash in this situation
    ;
    ; if root drive, Return True
    ; if not root, Return False
EndFunc

I hope that I explained it well enough within the code box. I have literally zero understanding of regex.

Thank you for your time.

[WildByDesign]

I just noticed the _WinAPI_PathIsRoot() function which I may be able to work with.

My scenario does not provide the backslash which is required to return True with the _WinAPI_PathIsRoot() function. However, I can certainly append the backslash for this purpose or even modify the _WinAPI_PathIsRoot() slightly.

[MattyD]

PathIsRoot is probably the better solution, but just for the exercise.

• \A and \z matches the start and end of the string.
• [A-Za-z]: matches any letter and the colon
• \\? matches a backslash, ? means 0 or 1 times.

$sDriveC = "C:"
$sDriveD = "D:"
$sDriveE = "E:"
$sDriveR = "R:"
$sNotRoot = "C:\Example"

If IsRootDrive($sDriveC) Then ConsoleWrite("This is root drive." & @CRLF)
If Not IsRootDrive($sNotRoot) Then ConsoleWrite("This is not a root drive." & @CRLF)

Func IsRootDrive($sDrive)
    ;
    ; something like:
    ; "*:"
    ; needs to confirm 2 characters
    ; first character being a single drive letter
    ; second character being a colon
    ; there is no backslash in this situation
    ;
    ; if root drive, Return True
    ; if not root, Return False


;~  Return StringRegExp($sDrive, "\A[A-Za-z]:\\?\z") ;Optionally has backslash
    Return StringRegExp($sDrive, "\A[A-Za-z]:\z")
EndFunc

If you're interested and have the time, I believe there's a tutorial in the autoit help file on regular expressions. They can be a bit of a headache at times, but it's a powerful thing to have the kit bag

[jchd]

Warning that subst-ed drives may point to non-root, soft and hard links as well.

[WildByDesign]

On 1/1/2026 at 8:04 PM, MattyD said:

If you're interested and have the time, I believe there's a tutorial in the autoit help file on regular expressions. They can be a bit of a headache at times, but it's a powerful thing to have the kit bag

Thank you for the script. It always blows my mind how small the regex is. Small yet powerful.

I think that you are right. I should learn at least some of the basics of regex. I don't think that I would quite need anything more advanced with it but the basics would be good to learn. I'll do some reading today.

49 minutes ago, jchd said:

Warning that subst-ed drives may point to non-root, soft and hard links as well.

Good point, thank you. I haven't quite gotten that far yet with the script but that is absolutely a solid point.