choroba is correct.
Though if this were some sort of riddle, I'd respond with this:
cat << EOF | sh
> echo 'visit:$site'
> EOF
As jander points out this is wide open for an injection attack. It wasn't a serious answer, so if anyone was considering using something like this, don't use it with untrusted input. For example, validate the $site string as being a valid URL before blindly executing the content. Something like thisthis could help (but the expression provided isn't perfect because it still allows injection, but use that sort of mechanic to test it).