Add to a plugin or to a theme’s functions.php file.
The PHP Code
function custom_media_column_headings($defaults) {
$defaults['parr_filename'] = 'Filename';
return $defaults;
}
function custom_media_column_content($column_name,$id) {
$none = 'None';
switch ($column_name) {
case 'parr_filename':
$filename = basename(get_attached_file($id));
echo $filename ? $filename : $none;
break;
}
}
add_filter('manage_media_columns','custom_media_column_headings');
add_action('manage_media_custom_column','custom_media_column_content',10,2);