shorten.php

<?php

/**
 * .htaccess file:
 * 
 * RewriteEngine On
 * RewriteBase /
 * 
 * # Skip existing files and directories
 * RewriteCond %{REQUEST_FILENAME} !-f
 * RewriteCond %{REQUEST_FILENAME} !-d

 * # Placeholder for shortened URLs
 * # shorten.php will append rules below this line
 * # ------------------ SHORT LINKS BELOW ------------------
 */

// Configuration
$htaccessFile = '.htaccess';
$slugLength = 5;

// Create random slug
function generateSlug($length = 5): string {
    return substr(str_shuffle(str_repeat('abcdefghijklmnopqrstuvwxyz', $length)), 0, $length);
}

// Check if slug already exists in .htaccess
function slugExists($slug, $file): bool {
    if (!file_exists($file)) return false;
    $contents = file_get_contents($file);
    return str_contains($contents, "RewriteRule ^$slug\\b");
}

// Store redirect rule in .htaccess
function saveToHtaccess($slug, $url, $file): bool {
    $rule = "RewriteRule ^$slug\$ $url [R=302,L]" . PHP_EOL;
    return file_put_contents($file, $rule, FILE_APPEND | LOCK_EX) !== false;
}

// Handle form submission
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $url = trim($_POST['url'] ?? '');

    if (!filter_var($url, FILTER_VALIDATE_URL)) {
        die("Invalid URL.");
    }

    do {
        $slug = generateSlug($slugLength);
    } while (slugExists($slug, $htaccessFile));

    if (saveToHtaccess($slug, $url, $htaccessFile)) {
        echo "Short URL created: <a href='/$slug'>/$slug</a>";
    } else {
        echo "Failed to save to .htaccess.";
    }

    exit;
}
?>

<form method="post">
    <input type="url" name="url" required placeholder="Enter full URL">
    <button type="submit">Shorten</button>
</form>