PHP: How to rename folders

Question

I'd like to ask you for a one small thing.
I have a few another folders in a main folder. This sub-folders are named:

v1, v2, v3, v4...

I would like to know, when I delete one of these folders,

e.g. v2 -> so I have v1, v3, v4

how to rename all of this folders back to

v1, v2, v3.

I tried this code, but it doesn't work:

$path='directory/';
$handle=opendir($path);
$i = 1;
while (($file = readdir($handle))!==false){
    if ($file!="." && $file!=".."){
        rename($path . $file, $path . 'v'.$i);
        $i++;
    }

Thank you!

Answer 1

This code retrieves all the directories with names starting with "v" followed by numbers.

Directories filtered: v1, v2, v3, .....
Directories excluded: v_1, v2_1, v3a, t1, ., .., xyz

Final directories: v0, v1, v2, v3, .....

If the final directories needs to start from v1, then I would again get the directories list and perform one more renaming process. I hope this helps!

$path='main_folder/'; $handle=opendir($path); $i = 1; $j = 0; $foldersStartingWithV = array();  

// Folder names starts with v followed by numbers only
// We exclude folders like v5_2, t2, v6a, etc
$pattern = "/^v(\d+?)?$/";

while (($file = readdir($handle))!==false){
    preg_match($pattern, $file, $matches, PREG_OFFSET_CAPTURE);

    if(count($matches)) {
    // store filtered file names into an array
    array_push($foldersStartingWithV, $file);
    }
}

// Natural order sort the existing folder names 
natsort($foldersStartingWithV);  

// Loop the existing folder names and rename them to new serialized order
foreach($foldersStartingWithV as $key=>$val) {
// When old folder names equals new folder name, then skip renaming
    if($val != "v".$j) {
        rename($path.$val, $path."v".$j);
    }
    $j++;
}