flatpress/fp-plugins/searchbox/plugin.searchbox.php

<?php
/*
 * Plugin Name: SearchBox
 * Version: 1.0
 * Plugin URI: https://www.flatpress.org
 * Author: FlatPress
 * Author URI: https://www.flatpress.org
 * Description: Adds a search box widget. Part of the standard distribution.
 */
define('SEARCHBOX_BIG', false);

function plugin_searchbox_widget() {
	global $lang;

	$url = BLOG_BASEURL . 'search.php';

	$content = '<ul><li>
		<form method="get" action="' . $url . '">
		<input type="hidden" name="stype" value="full" />';

	if (SEARCHBOX_BIG)
		$content .= "<p><a href=\"{$url}\">{$lang['search']['moreopts']}</a></p>";

	$content .= '<p><input type="text" name="q" /></p>';

	if (SEARCHBOX_BIG)
		$content .= '<p><label><input type="radio" 
					name="stype" value="titles" checked="checked" />' . $lang ['search'] ['onlytitles'] . '</label><br />' . '<label><input type="radio" name="stype" value="full" />' . $lang ['search'] ['fulltext'] . '</label></p>';

	$content .= '<div class="buttonbar"><p><input name="search" type="submit" value="' . $lang ['search'] ['submit'] . '" /> </p></div>
		</form>
		</li></ul>';

	return array(
		'subject' => $lang ['search'] ['head'],
		'content' => $content
	);
}

register_widget('searchbox', 'SearchBox', 'plugin_searchbox_widget');

?>