require_once(' ')をすると何も表示されなくなる

php
1<?php
2    require_once('config.php');     
3    require_once('functions.php'); 
4?>
5<!DOCTYPE html>
6<html lang="ja">
7<head>
8    <meta charset="utf-8">
9    <meta http-equiv="X-UA-Compatible" content="IE=edge">
10    <meta name="viewport" content="width=device-width, initial-scale=1">
11    <meta name="Description" content="example">
12    <title>example</title>
13    <link rel="stylesheet" href="index.css">
14    <!--[if lt IE 9]>
15        <script src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script>
16        <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
17    <![endif]-->
18</head>
19<body>
20    <h1>お問い合わせ</h1>
21</body>
22</html>
23

上記の**require_once('config.php');require_once('functions.php'); を消せば<h1>お問い合わせ</h1>**が表示されるのですが、**require_once('config.php');require_once('functions.php'); があるとgaaruto<h1>お問い合わせ</h1>**が表示されません。なぜですか？

config.php

php
1<?php
2
3    define('DSN','mysql:host=localhost;dbname=contacts_php');  
4    define('DB_USER','dbuser'); 
5    define('DB_PASS','**********'); 
6
7    define('SITE_URL','http://example.loc/contacts_php/');
8    define('ADMIN_URL', SITE_URL.'admin/');
9
10    error_reporting(E_ALL & ~E_NOTICE); 
11
12    session_set_cookie_params(0,'/contacts_php/');
13

functions.php

php
1<?php
2    function connectDB(){
3        try{
4            rerurn new PDO(DSN, DB_USER, DB_PASS);
5        }catch(PDOException $e){
6            echo $e->getMessage();
7            exit;
8        }
9    }
10
11    function h($s){
12        return htmlspecialchars($s, ENT_QUOTES, "UTF-8");
13    }
14