wp_check_filetype_and_ext()

wp_check_filetype_and_ext() — Attempts to determine the real file type of a file. If unable to, the file name extension will be used to determine type. If it’s determined that the extension does not match the file’s real type, then the “proper_filename” value will be set with a proper filename and extension. Currently this function only supports renaming images validated via wp_get_image_mime().

Inputs: $file (string): Full path to the file. $filename (string): The name of the file (may differ from $file due to $file being in a tmp directory). $mimes (string[]|null): Optional. Array of allowed mime types keyed by their file extension regex. Defaults to the result of get_allowed_mime_types().

Returns array: Values for the extension, mime type, and corrected filename. Field $ext (string|false): File extension, or false if the file doesn’t match a mime type. Field $type (string|false): File mime type, or false if the file doesn’t match a mime type. Field $proper_filename (string|false): File name with its correct extension, or false if it cannot be determined.