How can I find the current language in a Laravel view?

BenjaminRH's answer is very good, and his suggested approach works perfectly. I've improved the snippet a bit. Now it detects the browser language and checks if that language is supported according to the application's config file.

It's a quick hack, but it works on my app. Note that the application language is also set now. Feel free to use ore improve it.

Route::filter('before', function()
{
    // current uri language ($lang_uri)
    $lang_uri = URI::segment(1);

    // Set default session language if none is set
    if(!Session::has('language'))
    {
        // use lang in uri, if provided
        if(in_array($lang_uri, Config::get('application.languages')))
        {
            $lang = $lang_uri;  
        }
        // detect browser language
        elseif(isset(Request::server('http_accept_language')))
        {
            $headerlang = substr(Request::server('http_accept_language'), 0, 2);

            if(in_array($headerlang, Config::get('application.languages')))
            {
                // browser lang is supported, use it
                $lang = $headerlang;
            }
            // use default application lang
            else
            {
                $lang = Config::get('application.language');
            }
        }
        // no lang in uri nor in browser. use default
        else 
        {
                // use default application lang
                $lang = Config::get('application.language');            
        }

        // set application language for that user
        Session::put('language', $lang);
        Config::set('application.language',  $lang);
    }
    // session is available
    else
    {
        // set application to session lang
        Config::set('application.language', Session::get('language'));
    }

    // prefix is missing? add it
    if(!in_array($lang_uri, Config::get('application.languages'))) 
    {
        return Redirect::to(URI::current());
    }
    // a valid prefix is there, but not the correct lang? change app lang
    elseif(in_array($lang_uri, Config::get('application.languages')) AND $lang_uri != Config::get('application.language'))
    {
        Session::put('language', $lang_uri);
        Config::set('application.language',  $lang_uri);    
    }
});

In the newer Laravel versions, you can get the current language with:

Config::get('app.locale');

The cleanest way to know the current language of your website in Laravel appears to be :

Lang::locale();

https://laravel.com/api/5.8/Illuminate/Translation/Translator.html#method_locale

It's different than this command that will return the default language of your website :

Config::get('app.locale');

An alternative, a bit shorter way could be using something like this:

app()->getLocale()

The advantage of this is that IDEs such as PHPStorm recognize this function and can help you develop much faster.