All You Need To Know About Finger Protocol

Here is the amazing case study and a open source.

Are you curious about TPC/IP's Finger utility? You are not alone. This gives a terrific overview on this search tool, with some examples of how to use it, and some alternatives commonly used today.  

Have you noticed that Windows NT and Windows 2000 have a TCP/IP utility called Finger? If you have, you’ve probably wondered what this Finger utility is and what you would use it for. Well, the Finger utility is an old TCP/IP tool that matches an e-mail address with the person who owns it and provides information about that person. While the Finger utility is actually a bit archaic—there are now more advanced tools out there that perform the same general operation—it still works and can be a useful tool in some situations

In this Daily Feature, I’ll introduce you the Finger utility and provide a little background. I’ll show you how to use the Finger utility in Windows NT and Windows 2000. I’ll also tell you about some of the Finger utility’s modern counterparts.

A bit of history on Finger
The Finger utility is actually called the Finger Information Protocol and was designed to provide an interface to the Remote User Information Program (RUIP). RUIP provides information about users who have accounts on UNIX-based computer networks. The Finger utility came into being six years before the Internet was born. In fact, the first documentation on the Finger utility is dated Dec. 1977, in a document titled RFC742. (You can view and learn more about this document on the Internet RFC/STD/FYI/BCP Archives.)
 
Since the utility was basically designed for tracking down people and at the time, a popular slogan for marketing the use of the phone book’s yellow pages was “Let your fingers do the walking,” the utility was christened “Finger.” Finger Information Protocol provided UNIX users on college campuses with the ability to create a fairly elaborate profile, called a Plan page, which could include personal and job-related information. You can think of a Plan page as the crude equivalent of a personal home page on the Internet today. Thus, when someone “Fingered” your e-mail address, they learned more about you.

Using the Finger utility
Since the Finger utility is a command line tool, to use it in either Windows NT or Windows 2000, you have to first access a command prompt window. You then type the command followed by an e-mail address.

The syntax for the Finger utility is
Finger [-l] [user] @hostname

The parameters are described in Table A.

Table A

Parameter	Description
-l	Specifies the use of the long list format
User	Indicates the user you want information about
@hostname	Specifies the hostname or IP address of the system whose users you want information about

Finger utility parameters

For example, if you wanted to learn more about a person whose e-mail address is jimbob@andrew.cmu.edu, you would type:
Finger jimbob@andrew.cmu.edu

While this is a fictitious account, if it were real, the results returned by the server might look something like those shown below. In this example, the Finger server provided some basic information about the user, such as the name, phone number, login name, and when the person last logged on to the server. There’s also a brief Plan page.
 [andrew.cmu.edu]
          name:    Jim R. Bobbins
         phone:    502-555-1212
   affiliation:    Senior, Computer Science
    login name:    jimbob
  account used:    Mon Apr 30 22:36 (7 days 13 hours ago)
        e-mail:    jimbob@andrew.cmu.edu
          Plan:    Graduating in May and am pursuing a Master’s degree in Computer Science at Washington University in St. Louis.

If there isn’t any information to display or if the Finger server isn’t running, the Finger utility will return an error message stating that either the connection was refused or it timed out. However, it may also return just a login name, which usually indicates the account doesn’t exist.

If you know the person’s name and that they have an account on a certain server, you can also try using either the first name or the last name. For example, you could use command:
Finger jim@andrew.cmu.edu

or
Finger bobbins@andrew.cmu.edu

Of course if there is more than one account using either of these names, the Finger command will display information about all the users with those names.

You can also just Finger the host system with the command:
Finger @andrew.cmu.edu

This form of the command will display a summary of all the users logged on to the server. If you omit the user parameter and just use the @hostname parameter, you can get information about all the users on the specified host.

Is it still a viable tool?
As you may have guessed by now, only UNIX-based servers running the Finger server (or Finger daemon) support the Finger Information Protocol. Thus, you can only use the Finger utility to track down information about users with accounts on UNIX-based servers. Furthermore, not all UNIX administrators permit their servers to be subject to the Finger utility due to privacy and security concerns. For example, a hacker with a valid login name provided by the Finger command can systematically attempt to guess the password associated with that login name and try to break in to the server. Even so, the Finger utility is still a useful tool to have in your arsenal. In certain situations, it can provide you with ways to quickly access information that might not be available elsewhere.

Web-to-Finger gateways
If you’re not running Windows NT or Windows 2000 but want to experiment with the Finger utility, you can download a shareware Finger client, such as Total Finger, or you can visit a Web-to-Finger Gateway site. These sites will provide you with a way to send a Finger command via a form on a Web page. For example, you can visit Brett’s Web to Finger Gateway to find out if someone is logged on to his or her account and see some basic information that they’ve supplied.

Finger alternatives
Since the days when the Finger utility and UNIX reigned over the Internet, other more universal technologies for searching for people on the Internet have been developed. For example, Lightweight Directory Access Protocol (LDAP), which is a set of protocols for accessing information directories, has been employed to create global directories of names, e-mail addresses, and phone numbers. These LDAP databases are now available on the Internet via Web browsers as well as many popular e-mail programs.

For example, using your Web browser, you can search for people and e-mail addresses at Bigfoot.com, Lycos Network’s WhoWere, or at Yahoo’s People Search just to name a few. At these sites, you’ll fill in a form, initiate your search, and view the results within a matter of seconds.

If you’re using Eudora, Netscape Communicator, or Outlook Express, you can easily perform similar searches from within your e-mail client. To do so within Outlook Express, open the Address Book and click the Find People button on the toolbar. When the Find People dialog box appears, select one of the directory servers in the Look In dropdown list, type in a name or e-mail address, and click the Find Now button. The results will then be displayed at the bottom of the Find People dialog box.

Conclusion
Many folks are unfamiliar with the TCP/IP Finger utility that is shipped with Windows NT and Windows 2000. Now that I’ve introduced you to the utility and explained how to use it to search for information about people on the Internet, you can try it out with a shareware version or via a command prompt in Windows NT or 2000.

and also look at ars technica post.