How to make Cyrillic readable in HTTP_REFERER?

Question

PHP

I have a PHP handler for sending requests to mail, it contains the element [email protected]$_SERVER['HTTP_REFERER']. , to indicate the link that the client came from.
Part of this link is in Cyrillic (dynamic utm tags). At the same time, a link of the following form is sent to the mail: test.ru/?utm_source=%D0%A2%D0%95%D0%A1%D0%A2
Is it possible to make the link displayed in Cyrillic in the received letter, or "on the fly" converted to transliteration?

Answer 1

$str = 'test.ru/?utm_source=%D0%A2%D0%95%D0%A1%D0%A2';
print urldecode($str);

test.ru/?utm_source=ТЕСТ

Answer 2

instead of putting a text link in the body of the email, put its html incarnation

<a href='http://ссылка'>текст, который будет виден в письме, подчеркнутым как ссылка</a>

in the text, you can write anything and in any way, as long as the headings of the letter and in the head correspond to the encoding