headers dynamically read in foreach loop php

Loop doesn't wait for PDF download process, that why you need to call function inside the loop, because loop is waiting for function process end.

function downloadFile(){

            $fileeename=$fileenames.'.pdf';
            $dl_file = preg_replace("([^\w\s\d\-_~,;:\[\]\(\).]|[\.]{2,})",'',$fileeename);
            $dl_file = filter_var($dl_file, FILTER_SANITIZE_URL);
            $fullPath = $path.$dl_file;
            if ($fd = fopen ($fullPath, "r"))
            {
                    $fsize = filesize($fullPath);
                    $path_parts = pathinfo($fullPath);
                    $ext = strtolower($path_parts["extension"]);

                    header("Content-type: application/pdf");
                    header("Content-Disposition: attachment; filename=\"".$path_parts["basename"]."\"");
                    header("Content-length: $fsize");
                    header("Cache-control: private");
                    while(!feof($fd)) {
                        $buffer = fread($fd, 2048);
                        echo $buffer;
                    }
            }
            fclose ($fd);
        } 

    foreach($file_names as $key){
             downloadFile();
    }