Prior to the finger program, the only way to get this information was with a who program that showed IDs and terminal line numbers for logged-in users, and people used to run their fingers down the who list. Earnest named his program after this concept.
Finger is based on the Transmission Control Protocol, using TCP port 79 decimal. The local host opens a TCP connection to a remote host on the Finger port. An RUIP (Remote User Information Program) becomes available on the remote end of the connection to process the request. The local host sends the RUIP a one line query based upon the Finger query specification, and waits for the RUIP to respond. The RUIP receives and processes the query, returns an answer, then initiates the close of the connection. The local host receives the answer and the close signal, then proceeds closing its end of the connection.
The Finger user information protocol is based on RFC 1288 (The Finger User Information Protocol, December 1991). Typically the server side of the protocol is implemented by a program fingerd (for finger daemon), while the client side is implemented by the name and finger programs which are supposed to return a friendly, human-oriented status report on either the system at the moment or a particular person in depth. There is no required format, and the protocol consists mostly of specifying a single command line. It is implemented on Unix, Unix-like systems and current versions of Windows.
The program would supply information such as whether a user is currently logged-on, e-mail address, full name etc. As well as standard user information, finger displays the contents of the .project and .plan files in the user's home directory. Often this file (maintained by the user) contains either useful information about the user's current activities, or alternatively all manner of humor.
fingerd(among others) to spread.
For these reasons, while finger was widely used during the early days of Internet, by the 1990s the vast majority of sites on the internet no longer offered the service. Notable exceptions include John Carmack and Justin Frankel, who until recently still updated their status information occasionally. In late 2005, John Carmack switched to using a blog, instead of his old