The Unix Finger

Is there a way to find out what users are connected to a server? For example, if I want to see if a particular someone is currently connected to a commercial ISP like AOL, can I finger the AOL server? When I have tried this there seems to be some server communication but I never get a response.


More and more, finger has been turned off or buried behind firewalls so that you can’t use it. A few schools and research institutions still allow it, but as far as I can tell the popularity of it has been going downhill for at least the last ten years and it’s gotten to the point where I’m almost surprised if I get anything back from the request.

Some of the functionality of the ‘finger’ command has been taken over and improved upon by authentication daemons. While a lot of places are not willing to give a random external site a complete listing of who’s logged on, they are somewhat more willing to tell an external site that a local user is attempting to connect to what the username of the person concerned is.

You specifically mention AOL. If all you want is to check and see if your buddies are on, you can get the AOL Instant Messenger and try that. I don’t know if other large ISPs have something similar or not.

Alternatively, you could get ICQ and persuade your friends to do the same.

Time was when you could often do:


and get the whole dealie.

Nowadays, as torq sez, most places have finger disabled. I used to use finger for browsing people’s .plan files, but now they’re on the web (indeed, many old schoolers call their web directories “hyplan”, for Hy[pertext] plan file), and for checking to see if I had the right email address after getting infuriating bounces. The former function is taken care of by the web, the second can occasionally be achieved by hacking in through the mail port thusly:

>telnet 25
connected to, awaiting somethingorother
Hello yourmailserver.what.ever, pleased to meet you
>vrfy joeblow
ERROR: No such user
>vrfy jblow
ERROR: No such user
>vrfy josephb

I may have made the last line up. Your results may vary wildly. Haven’t had to do it in ages.


A lot of places have turned off VRFY, too (or at least made it unusable: quite a few sites will happily verify that djkldsfjsdfj or any other line noise you type in is a valid user).

Some places have VRFY turned off, but EXPN still works. Others have both turned off.

It would be a worthwhile exercise to try a RCPT TO:<jblow> and then quit.