Custom extension get_client_version supports more client information

gitbox 2025-05-11

When developing web applications, understanding the details of the client can help us perform more granular functional adaptation, security verification, and user behavior analysis. PHP is a flexible server-side language that can parse the client's User-Agent through functions, but we can also implement more powerful and extensible client information extraction functions through the customized get_client_version function.

1. Basic ideas

The core purpose of the get_client_version function is to extract the client's type (such as browser, operating system, device type) and version information from the request header. We will implement this by parsing $_SERVER['HTTP_USER_AGENT'] and support loading custom extension rules.

2. Function implementation

The following is the basic version of the get_client_version function implementation, and supports loading user-defined extensions:

 function get_client_version($user_agent = null, $custom_rules = []) {
    if (is_null($user_agent)) {
        $user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
    }

    $clients = [
        'Chrome' => '/Chrome\/([0-9\.]+)/',
        'Firefox' => '/Firefox\/([0-9\.]+)/',
        'Safari' => '/Version\/([0-9\.]+).*Safari/',
        'Edge' => '/Edg\/([0-9\.]+)/',
        'Opera' => '/OPR\/([0-9\.]+)/',
        'Internet Explorer' => '/MSIE\s([0-9\.]+);/',
        'Windows' => '/Windows NT ([0-9\.]+)/',
        'macOS' => '/Mac OS X ([0-9_\.]+)/',
        'iOS' => '/iPhone OS ([0-9_\.]+)/',
        'Android' => '/Android ([0-9\.]+)/',
    ];

    // Merge custom rules
    if (!empty($custom_rules) && is_array($custom_rules)) {
        $clients = array_merge($clients, $custom_rules);
    }

    $result = [];

    foreach ($clients as $name => $pattern) {
        if (preg_match($pattern, $user_agent, $matches)) {
            $result[$name] = str_replace('_', '.', $matches[1]);
        }
    }

    return $result;
}

3. Use examples

 $client_info = get_client_version();

// Output client information
echo '<pre>';
print_r($client_info);
echo '</pre>';

4. Support custom extensions

You can detect exclusive client characteristics by passing custom rules, such as customized application clients within the enterprise or some special browser shells.

 $custom_rules = [
    'MyAppClient' => '/MyApp\/([0-9\.]+)/'
];

$client_info = get_client_version(null, $custom_rules);

// Output client information，Include custom content
echo '<pre>';
print_r($client_info);
echo '</pre>';

V. Typical application scenarios

User analysis : Statistics the browser and version distribution used by users.
Functional compatibility processing : Compatibility optimization is made for different browsers or systems.
Security Policy : Identify unsupported clients and prohibit access.
API Restrictions : Restrict certain clients to call certain interfaces based on client information.

VI. Deployment Suggestions

It is recommended to call get_client_version at the public entrance of the project and cache the results to $_SESSION or logging.
For high concurrency environments, it is recommended to combine Redis or file cache to avoid repeated parsing.

7. Reference link

User agent information can refer to MDN's documentation: https://developer.mozilla.org/
More browser identifiers: https://www.useragentstring.com/

get_client_version