How to url-encode only non-ASCII symbols of URL in PHP, but leave reserved symbols un-encoded?

Question

I have a URL that looks like this (note the “„ symbols):

http://tinklarastis.omnitel.lt/kokius-aptarnavimo-kanalus-klientui-siulo-„omnitel“-1494

I receive it from SimplePie parser, if that matters. Now, if you try going to this specific URL in your browser and copy it from the address bar, you would get a URL that has the non-ASCII symbols percent encoded:

http://tinklarastis.omnitel.lt/kokius-aptarnavimo-kanalus-klientui-siulo-%E2%80%9Eomnitel%E2%80%9C-1494

I am trying to understand how can I mimic the same conversion in PHP. I cannot simply use urlencode() or urlrawencode() as they encode both non-ASCII symbols and reserved symbols, while in my case the reserved symbols (/?&, etc) should stay as they are.

So far I have only seen solutions that involve splitting the URL into pieces between reserved symbols and then using urlencode(), but that feels hackish to me and I hope there's a more elegant solution. I have tried various variations of iconv(), mb_convert_encoding(), yet with no success yet.

Answer 1

I have a simple one-liner that I use to do in-place encoding only on non-ASCII characters using preg_match_callback:

preg_replace_callback('/[^\x20-\x7f]/', function($match) {
    return urlencode($match[0]);
}, $url);

Note that the anonymous function is only supported in PHP 5.3+.

Answer 2

After researching a bit, I came to a conclusion that there's no way to do nicely in PHP (however, other languages like python / perl do seem to have functions exactly for this use case). This is the function I came up with (ensures encoding of path fragment of the URL):

function url_path_encode($url) {
    $path = parse_url($url, PHP_URL_PATH);
    if (strpos($path,'%') !== false) return $url; //avoid double encoding
    else {
        $encoded_path = array_map('urlencode', explode('/', $path));
        return str_replace($path, implode('/', $encoded_path), $url);
    }   
}