whoami, or who am i is a UNIX command for showing the username of the current user.

And we could use the $_SERVER variable in PHP to extract some information of the visitor (Yes, you. Big brother is watching you!).

$_SERVER['HTTP_USER_AGENT']

CCBot/1.0 (+http://www.commoncrawl.org/bot.html)

$_SERVER['REMOTE_ADDR'] + $_SERVER['REMOTE_PORT'] (Your IP address and port)

38.107.179.226:35779 (You are from Washington, District of Columbia, United States [Show on Google Maps])

$_SERVER['HTTP_REFERER']