setcookie(
  <key>,
  <data here>,
  time()+60*60*24*30,
  $_SERVER['HTTP_HOST']=="localhost"?"/ivy/":"/",
  $_SERVER['HTTP_HOST'],
  $_SERVER['HTTP_HOST']=="localhost"?false:true,
  true
);

// The documentation for it - matching up params.
bool setcookie (
  string $name
  [, string $value
  [, int $expire = 0
  [, string $path
  [, string $domain
  [, bool $secure = false
  [, bool $httponly = false ]]]]]] )