#include <Array.au3>
#include <File.au3>

;The directory to search in
Global $workingDirectory = "C:\Users\User\Desktop\New folder"

;Create an array of all the CHKNs found in the working directory
$array = _FileListToArray($workingDirectory, "*.chkn")

;If no CHKNs were found
If @error = 4 Then
   MsgBox($MB_SYSTEMMODAL, "", "No CHKNs were found.")
   Exit
EndIf

;Iterate through the CHKNs
For $i = 1 to $array[0]
   Local $newName = genRandomName()

   FileMove($workingDirectory & "\" & $array[$i], $workingDirectory & "\" & $newName & ".chkn")

   ConsoleWrite($array[$i] & " was renamed to " & $newName & ".chkn" & @LF);
Next



;This function returns a random string
Func genRandomName()
   ;Create an array of ASCII codes to generate the string from.
   ;We do this rather than using Chr(Random(num,num,1)) because
   ;this is less work
   Local $characters = StringToASCIIArray("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")

   ;create a variable to store the random string in
   Local $name = ""

   ;the size of the random string to generate
   Local $size = 10

   For $i = 1 To $size
     ;Create local variable to store the previously chosen character
     Local $previousC = ""

     ;Create a variable to store the chosen character and give it a value
     ;by selecting a random ASCII code from the $characters array And
     ;converting it to a character
     Local $c = Chr($characters[Random(1, UBound($characters))])

     ;prevent duplicate characters side-by-side by repeatedly generating a new character
     ;using the same technique as above until a unique one is found
     Do
       $c = Chr($characters[Random(1, UBound($characters))])
       ;ConsoleWrite($c & @LF)
     Until Not ($c = $previousC)

     ;Set the newly selected character as the previous one
     $previousC = $c

     ;append the character to the string
     $name &= $c
   Next

   Return $name
EndFunc