remote user name

Is it possible to get remote us开发者_高级运维ername when I get a referral link without involving any server side code from the referral link?

Do you mean like if I clicked a link to your site on Stack Overflow, you would want to be able to see that my username is "Agent Conundrum"? No, you can't do that without the help of the referring site. The only information you should be able to get is the (permanently misspelled) HTTP_REFERER in the $_SERVER superglobal array, which tells you the page the user came from. Even then, there are ways to block or change this so you shouldn't count on it being set (especially since it wouldn't be set if the user navigated directly to your page via the address bar).

Frankly, I wouldn't want to use a site that leaked personal information (and for some sites, even the username qualifies as personal information), and I wouldn't want to use a site that tries to harvest such leaked information without my knowledge.

Generally, any site where you have a legitimate reason to broadcast this information would have some sort of API built in, like FacebookConnect. Even then, it should be strictly opt-in for the user.

As a general thing: no. The HTTP protocol does not involve the transmission of a remote user name.

Hey, it could help to answer if you would be a little more specific on which kind of service are you trying to fetch the data from.

Large/Public services tend to have somekind of an accessible API that you can fork on your referrer, but other than that its mostly that you need to regexp the site and know the structure of the HTML pretty much.