I am working on a plain PHP project where I have some files structures as below.

project_folder
--> .env
--> autoload.php
--> index.php
--> Controllers
    --> IndexController.php

Now my files contain the below codes.

.env

# App Constants
APP_ENV = localhost
APP_URL = http://localhost/project_folder
APP_DOMAIN = https://localhost/project_folder
APP_DIR = __DIR__

# Database Connection
DATABASE_HOST = localhost
DATABASE_NAME = test
DATABASE_USER = root
DATABASE_PASSWORD = root

autoload.php

$ENV_filepath = '.env';
$lines = file($ENV_filepath, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
foreach ($lines as $line) {
    if (strpos(trim($line), '#') === 0) {
        continue;
    }
    list($name, $value) = explode('=', $line, 2);
    $name = trim($name);
    $value = trim($value);
    if (!array_key_exists($name, $_SERVER) && !array_key_exists($name, $_ENV)) {
        putenv(sprintf('%s=%s', $name, $value));
        $_ENV[$name] = $value;
        $_SERVER[$name] = $value;
    }
}

index.php

<?php
session_start();
require_once 'autoload.php';
?>
<form onsubmit="return submitted(this)">
    <input type="text" name="UserName" required="" maxlength="200">
    <input type="password" name="UserPassword" required="" maxlength="200">
    <div id="showGeneralAjaxMsg"></div>
    <input type="submit" title="Sign In Now" value="Sign In"/>              
</form> 
<script type="text/javascript">
function submitted(incomingForm) {
    var FD = new FormData(incomingForm);
    FD.append("Function", "Login");
    var ajx = new XMLHttpRequest();
    ajx.onreadystatechange = function () {
        if (ajx.readyState == 4 && ajx.status == 200) {
            document.getElementById("showGeneralAjaxMsg").innerHTML = ajx.responseText;
        }
    };
    ajx.open("POST", "Controllers/IndexController.php", true);
    ajx.send(FD);
    document.getElementById("showGeneralAjaxMsg").innerHTML = "LOADING: Server Is Responding.";
    return false;
}
</script>

IndexController.php

<?php
echo "This Text Is Showing After Submit At index.php Page Only";
print_r($_ENV);
echo getenv('APP_ENV');
?>

But I am returning empty environment variables. Nothing is showing in the response result and I am only able to see "This Text Is Showing After Submit At index.php Page Only".

Now my question is that what is the scope of environment variables in PHP? Remember I am not using the OOP concept. It's simple programming. Also, I am confused that should I have to load the autoload.php file on each PHP page? If your answer is yes then I have some relative variables set in .env in future that can only be saved from the project root folder and not from any other level.

Waiting for a clarification...

CodePudding user response：

You may use session variables to store data in variables which can be accessed in different pages of the system

1. Say if the variable name is var1, then simply use $_SESSION['var1']
2. Make sure session_start(); is placed at the top of all the PHP scripts using the session variables

<?php

session_start();

$_SESSION['var1'] = $var1;


// other statements

?>