Drupal自定义模块无法工作

这是我的custom.info

name = Custom
description = Custom module
core = 7.x
package = Own

和custom.module

<?php
/**
 * @file
 * An example custom module for selecting, updating and deleting query
 */
/**
 * Implementation of hook_block_info()
 */
echo 'Today: 'n';
echo date('m/d/Y');
function custom_block_info() {
    $block['custom'] = array('info' => t('Custom block'))   
    return $block;
} 
/**
 * Implements hook_block_view.
 */
function custom_block_view($delta = '') {
  global $user;
  $block['content'] = t('Hello @user from IP @host',array(
    '@user' => format_username($user), 
    '@host' => $user->hostname`enter code here`
  ));
  $result = db_select('node','a')
    ->fields('a', array('title'))
    ->execute();
  foreach($result as $node) { 
    $items[] = array(
      'data' => t($node->title)
    );
  }
  $block['content'] .= theme('item_list', array(
    'items' => $items
  ));
  return $block;
}

但是这个自定义模块没有在我放置块的侧边栏中显示数据。我把echo语句放在代码上面，它甚至没有在块中显示echo语句，有人能告诉我如何解决这个????

注:我已经安装了drupal，我没有改变数据库!