README

Lightweight .env file loader for PHP. Zero dependencies.

Why This Library?

There are established .env loaders for PHP, most notably vlucas/phpdotenv. This library exists because we needed something simpler:

• Zero dependencies — Nothing to install besides this package.
• Thread-safe by design — Only writes to $_ENV. No putenv()/getenv(), which are not thread-safe in async runtimes (Swoole, RoadRunner, FrankenPHP).
• No magic — No variable expansion (${VAR}), no multiline values, no interpreted escape sequences (\n, \t). What you write is what you get.
• Minimal footprint — Easy to audit, easy to understand.

If you need variable expansion, multiline values, or getenv() support, use phpdotenv instead.

Installation

composer require sodaho/env-loader

Usage

Basic Usage

use Sodaho\EnvLoader\EnvLoader;

// Loads .env into $_ENV (does not overwrite existing, no required keys)
EnvLoader::load(__DIR__ . '/.env');

echo $_ENV['DB_HOST'];

Options

// Overwrite existing $_ENV variables
EnvLoader::load('.env', overwrite: true);

// Require specific keys (throws exception if missing)
EnvLoader::load('.env', required: ['DB_HOST', 'DB_NAME']);

// Required keys as comma-separated string
EnvLoader::load('.env', required: 'DB_HOST,DB_NAME');

// Combine options
EnvLoader::load('.env', overwrite: true, required: ['DB_HOST']);

Parse Without Loading

// Returns array without setting $_ENV
$values = EnvLoader::parse('.env');

print_r($values);
// ['DB_HOST' => 'localhost', 'DB_NAME' => 'myapp', ...]

Supported .env Syntax

# Comments
DB_HOST=localhost

# Empty values
EMPTY_VAR=

# Values with equals sign
PASSWORD=val=ue=with=equals

# Double quotes (supports escaped quotes)
MESSAGE="Hello World"
ESCAPED="Say \"Hello\""

# Single quotes (no escape processing)
SINGLE='Hello World'

# Inline comments
API_KEY=secret123 # this is ignored
QUOTED="value with # hash" # comment outside quotes

# export prefix
export DB_PORT=3306

# Whitespace is trimmed
  SPACED_KEY  =  value

Exceptions

All exceptions extend EnvLoaderException for easy catching:

use Sodaho\EnvLoader\EnvLoader;
use Sodaho\EnvLoader\Exception\EnvLoaderException;
use Sodaho\EnvLoader\Exception\FileNotFoundException;
use Sodaho\EnvLoader\Exception\MissingRequiredKeyException;

try {
    EnvLoader::load('.env', required: ['API_KEY']);
} catch (FileNotFoundException $e) {
    // File does not exist
} catch (MissingRequiredKeyException $e) {
    // Required key not found
} catch (EnvLoaderException $e) {
    // Any other EnvLoader error
}

Key Naming Rules

Valid keys must:

• Start with a letter or underscore
• Contain only letters, numbers, and underscores

DB_HOST      ✓
_PRIVATE     ✓
API_KEY_2    ✓
123KEY       ✗ (starts with number)
MY-KEY       ✗ (contains hyphen)
MY KEY       ✗ (contains space)

Why $_ENV Only?

This library intentionally writes only to $_ENV, not putenv() or $_SERVER.

Reason: Thread Safety

putenv() and getenv() are not thread-safe. In modern PHP runtimes like:

• Swoole
• RoadRunner
• FrankenPHP
• ReactPHP

...concurrent requests can overwrite each other's environment variables, causing hard-to-debug race conditions.

$_ENV is process-local and safe. Use $_ENV['KEY'] instead of getenv('KEY') in your application.

// Safe
$host = $_ENV['DB_HOST'];

// Not recommended (not set by this loader)
$host = getenv('DB_HOST');

When to Use

• Development environments
• Shared hosting where system ENV is not available
• Simple projects without framework
• Modern async PHP (Swoole, RoadRunner, FrankenPHP)

When NOT to Use

• Production with proper system ENV configuration
• When you need variable expansion (${OTHER_VAR})
• When you need multiline values
• When you must support legacy code using getenv()

Requirements

• PHP ^8.2

Acknowledgments

Parts of this project (refactoring, documentation, code review) were developed with AI assistance (Claude).

License

MIT