Just a basic block with a search box.
--- /dev/null
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Global search block.
+ *
+ * @package block_globalsearch
+ * @copyright Prateek Sachan {@link http://prateeksachan.com}
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Global search block.
+ *
+ * @package block_globalsearch
+ * @copyright Prateek Sachan {@link http://prateeksachan.com}
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class block_globalsearch extends block_base {
+
+ /**
+ * Initialises the block.
+ *
+ * @return void
+ */
+ public function init() {
+ $this->title = get_string('pluginname', 'block_globalsearch');
+ }
+
+ /**
+ * Gets the block contents.
+ *
+ * If we can avoid it better not check the server status here as connecting
+ * to the server will slow down the whole page load.
+ *
+ * @return string The block HTML.
+ */
+ public function get_content() {
+ global $OUTPUT;
+ if ($this->content !== null) {
+ return $this->content;
+ }
+
+ $this->content = new stdClass();
+ $this->content->footer = '';
+
+ if (\core_search\manager::is_global_search_enabled() === false) {
+ $this->content->text = get_string('globalsearchdisabled', 'search');
+ return $this->content;
+ }
+
+ $url = new moodle_url('/search/index.php');
+ $this->content->footer .= html_writer::link($url, get_string('advancedsearch', 'search'));
+
+ $this->content->text = html_writer::start_tag('div', array('class' => 'searchform'));
+ $this->content->text .= html_writer::start_tag('form', array('action' => $url->out()));
+ $this->content->text .= html_writer::start_tag('fieldset', array('action' => 'invisiblefieldset'));
+
+ // Input.
+ $this->content->text .= html_writer::tag('label', get_string('search', 'search'),
+ array('for' => 'searchform_search', 'class' => 'accesshide'));
+ $inputoptions = array('id' => 'searchform_search', 'name' => 'q', 'type' => 'text', 'size' => '15');
+ $this->content->text .= html_writer::empty_tag('input', $inputoptions);
+
+ // Search button.
+ $this->content->text .= html_writer::tag('button', get_string('search', 'search'),
+ array('id' => 'searchform_button', 'type' => 'submit', 'title' => 'globalsearch'));
+ $this->content->text .= html_writer::end_tag('fieldset');
+ $this->content->text .= html_writer::end_tag('form');
+ $this->content->text .= html_writer::end_tag('div');
+
+ return $this->content;
+ }
+}
--- /dev/null
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Global search Block caps.
+ *
+ * @package block_globalsearch
+ * @copyright Prateek Sachan {@link http://prateeksachan.com}
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+$capabilities = array(
+
+ 'block/globalsearch:myaddinstance' => array(
+ 'captype' => 'write',
+ 'contextlevel' => CONTEXT_SYSTEM,
+ 'archetypes' => array(
+ 'user' => CAP_ALLOW
+ ),
+
+ 'clonepermissionsfrom' => 'moodle/my:manageblocks'
+ ),
+
+ 'block/globalsearch:addinstance' => array(
+ 'captype' => 'write',
+ 'contextlevel' => CONTEXT_BLOCK,
+ 'archetypes' => array(
+ 'manager' => CAP_ALLOW
+ ),
+
+ 'clonepermissionsfrom' => 'moodle/site:manageblocks'
+ ),
+);
--- /dev/null
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Strings for component 'block_globalsearch'.
+ *
+ * @package block_globalsearch
+ * @copyright Prateek Sachan {@link http://prateeksachan.com}
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+$string['globalsearch:addinstance'] = 'Add a new global search block';
+$string['globalsearch:myaddinstance'] = 'Add a new global search block to Dashboard';
+$string['pluginname'] = 'Global search';
--- /dev/null
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Global Search version details.
+ *
+ * @package block_globalsearch
+ * @copyright Prateek Sachan {@link http://prateeksachan.com}
+ * @copyright Daniel Neis
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die;
+
+$plugin->version = 2016012000;
+$plugin->requires = 2015111000;
+$plugin->component = 'block_globalsearch';