How to change variables in the .env file dynamically in Laravel?

In Laravel, the .env file contains environment variables that configure your application's behavior across different environments (local, staging, production). While these variables are typically static, you can modify them dynamically using PHP file operations.

Understanding the .env File

The .env file contains key-value pairs for configuration

APP_NAME=Laravel
APP_ENV=local
APP_KEY=base64:BUdhVZjOEzjFihHKgt1Cc+gkQKPoA4iH98p5JwcuNho=
APP_DEBUG=true
APP_URL=http://localhost

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=test
DB_USERNAME=root
DB_PASSWORD=

These variables are used throughout Laravel's configuration files in the config/ folder and should not be committed to version control as they vary per environment.

Fetching Current Environment

You can retrieve the current environment using Laravel's App facade

<?php
use Illuminate\Support\Facades\App;

$environment = App::environment();
echo $environment;
?>

local

Reading Environment Variables

Use the env() helper function to fetch specific environment values

<?php
echo env('APP_URL');
echo "<br/>";
echo env('APP_ENV');
echo "<br/>";
echo env('DB_DATABASE');
?>

http://localhost
local
test

Changing Environment Variables Dynamically

To modify .env variables at runtime, read the file, replace values, and write back

<?php
$path = base_path('.env');
$envContent = file_get_contents($path);

if (file_exists($path)) {
    $newContent = str_replace(
        'APP_ENV=local', 
        'APP_ENV=production', 
        $envContent
    );
    file_put_contents($path, $newContent);
    echo "Environment changed to production";
}
?>

Alternative Method Using $_ENV

Access all environment variables using the global $_ENV array

<?php
print_r($_ENV);
?>

Array(
   [APP_NAME] => Laravel
   [APP_ENV] => local
   [APP_DEBUG] => true
   [DB_CONNECTION] => mysql
   [DB_HOST] => 127.0.0.1
   ...
)

Key Points

• Changes to .env require application restart in production
• Use escapeshellarg() when handling user input for security
• Consider using Laravel's config cache in production environments

Conclusion

Dynamic environment variable changes in Laravel require file manipulation using file_get_contents() and str_replace(). Always validate changes and restart your application to ensure new values take effect.