PHP Get Site URL Protocol - http vs https

Question

I know it's late, although there is a much more convenient way to solve this kind of problem! The other solutions are quite messy; this is how I would do it:

$protocol = stripos($_SERVER['SERVER_PROTOCOL'],'https') === 0 ? 'https://' : 'http://';

...or even without condition if you prefer:

$protocol = strtolower(substr($_SERVER["SERVER_PROTOCOL"],0,strpos( $_SERVER["SERVER_PROTOCOL"],'/'))).'://';

Have a look at $_SERVER["SERVER_PROTOCOL"]

This works for me

if (isset($_SERVER['HTTPS']) &&
    ($_SERVER['HTTPS'] == 'on' || $_SERVER['HTTPS'] == 1) ||
    isset($_SERVER['HTTP_X_FORWARDED_PROTO']) &&
    $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https') {
  $protocol = 'https://';
}
else {
  $protocol = 'http://';
}

It is not automatic. Your top function looks ok.

Some changes:

function siteURL() {
  $protocol = ((!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off') || 
    $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
  $domainName = $_SERVER['HTTP_HOST'];
  return $protocol.$domainName;
}

short way

$scheme = $_SERVER['REQUEST_SCHEME'] . '://';