apply_filters( ‘wp_unique_filename’, string $filename, string $ext, string $dir, callable|null $unique_filename_callback, string[] $alt_filenames, int|string $number )

Parameters

$filenamestring

Unique file name.

$extstring

File extension. Example: ".png".

$dirstring

Directory path.

$unique_filename_callbackcallable|null

Callback function that generates the unique file name.

$alt_filenamesstring[]

Array of alternate file names that were checked for collisions.

$numberint|string

The highest number that was used to make the file name unique or an empty string if unused.