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apply_filters( 'pre_wp_unique_filename_file_list', array|null $files, string $dir, string $filename )

Filters the file list used for calculating a unique filename for a newly added file.

Returning an array from the filter will effectively short-circuit retrieval from the filesystem and return the passed value instead.

$files: (array|null) The list of files to use for filename comparisons. Default null (to retrieve the list from the filesystem).
$dir: (string) The directory for the new file.
$filename: (string) The proposed filename for the new file.

Used By	Description
wp-includes/functions.php: wp_unique_filename()	Get a filename that is sanitized and unique for the given directory.

Version	Description
5.5.0	Introduced.