install_theme_search_form( bool $type_selector = true )

function install_theme_search_form( $type_selector = true ) {
	$type = isset( $_REQUEST['type'] ) ? wp_unslash( $_REQUEST['type'] ) : 'term';
	$term = isset( $_REQUEST['s'] ) ? wp_unslash( $_REQUEST['s'] ) : '';
	if ( ! $type_selector )
		echo '<p class="install-help">' . __( 'Search for themes by keyword.' ) . '</p>';
	?>
<form id="search-themes" method="get">
	<input type="hidden" name="tab" value="search" />
	<?php if ( $type_selector ) : ?>
	<label class="screen-reader-text" for="typeselector"><?php _e('Type of search'); ?></label>
	<select	name="type" id="typeselector">
	<option value="term" <?php selected('term', $type) ?>><?php _e('Keyword'); ?></option>
	<option value="author" <?php selected('author', $type) ?>><?php _e('Author'); ?></option>
	<option value="tag" <?php selected('tag', $type) ?>><?php _ex('Tag', 'Theme Installer'); ?></option>
	</select>
	<label class="screen-reader-text" for="s"><?php
	switch ( $type ) {
		case 'term':
			_e( 'Search by keyword' );
			break;
		case 'author':
			_e( 'Search by author' );
			break;
		case 'tag':
			_e( 'Search by tag' );
			break;
	}
	?></label>
	<?php else : ?>
	<label class="screen-reader-text" for="s"><?php _e('Search by keyword'); ?></label>
	<?php endif; ?>
	<input type="search" name="s" id="s" size="30" value="<?php echo esc_attr($term) ?>" autofocus="autofocus" />
	<?php submit_button( __( 'Search' ), '', 'search', false ); ?>
</form>
<?php
}