open_login.php

<?php
session_start();
$message = "You can open/close the gate<br>via Monban.";
if (isset($_POST["login"])) {
$local_id=$_POST["local_id"];
$file_name="i_files/i_$local_id.txt";
if(file_exists($file_name)){
$fp = fopen("i_files/i_$local_id.txt","r") or die("Error");
$the_time = fgets($fp);
fclose($fp);   
$hp = fopen("j_files/j_$the_time.txt","r") or die("Error");
$opcl = fgets($hp);
fclose($hp);    
if($opcl=="1"){
$message = "The gate is closed. <br>You can open it via Monban.";
goto a;
}    
if ($_POST["local_id"] == "FAWJG59" && $_POST["password"] == "647448") {
$_SESSION["local_id"] = $_POST["local_id"];
$local_id=$_POST["local_id"];       
$login_url = "https://{$_SERVER["HTTP_HOST"]}/files/file_$local_id.php";
header("Location: {$login_url}");
exit;
}else{$message = "ID and/or password is wrong.";}
a:
}else{$message = "no file";} 
}
?>
<!DOCTYPE html>	
<html lang="ja">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="style.css">		
<title>sample</title>
</head>
<body>
<header>
<p>sample</p>
</header>
<main>   
<form action="open_login.php" method="POST">
Local_ID:<input type="text" name="local_id" value="" /><br/><br>
password<input type="password" name="password" value="" />
<input type="submit" name="login" value="login" />
</form>
<p><a href="https://<?=$_SERVER['HTTP_HOST']?>/personal_ent.php">Monban</a></p>    
<p id="light">
<?php
if ($message) {print $message;}
?>
</p>
<p><a href="https://<?=$_SERVER['HTTP_HOST']?>/index.html">exit</a></p>
</main>
<footer>
</footer>
</body>
</html>
※サンプルのLocal_ID(=FAWJG59)やpassword(=647448)は各々のサイトに合わせて変更してください。
exit