Simple user identity detection in PHP

Question

What are some PHP identity detection libraries/functions that support cookies and IP? (and possibly other methods - like those in this awesome post: https://stackoverflow.com/a/16120977)?

I know cookies and IP are unreliable, this goes without saying.

Ideally, something like this:

if(!ID::detected())
{
  // my action (here, vote in a poll, one vote/day allowed)
  ID::establish(60 * 60 * 24, ID::COOKIE|ID::IP);
}

They should take care of logging the IPs to a file, and all. This is such a common problem I'm sure there are some, but somehow, 15 minutes of Googling failed me.

Thanks.