confirmed this one doesn't really purge cache:
but after adding my.url.domain.com's IP, it has worked!
i.e.,
#php purge_cache_byurl.php -r my.url.domain.com /hello.php IP-of-my.url.domain.com 80
the syntax is:
/usr/local/lsws/admin/misc>php purge_cache_byurl.php
Invalid arguments!
Usage: php...