computer network A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...

ing, the Name/Finger protocol and the Finger user information protocol are simple

network protocols A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics, and synchronization of ...

for the exchange of human-oriented status and user information.

Name/Finger protocol

The Name/Finger protocol is based on

Request for Comments A Request for Comments (RFC) is a publication in a series from the principal technical development and standards-setting bodies for the Internet, most prominently the Internet Engineering Task Force (IETF). An RFC is authored by individuals or ...

document RFC 742 (December 1977) as an interface to the name and finger programs that provide status reports on a particular computer system or a particular person at network sites. The finger program was written in 1971 by Les Earnest who created the program to solve the need of users who wanted information on other users of the network. Information on who is logged in was useful to check the availability of a person to meet. This was probably the earliest form of

presence information In computer network, computer and telecommunications networks, presence information is a status indicator that conveys ability and willingness of a potential communication partner—for example a user (computing), user—to communication, communicat ...

for remote network users. Prior to the finger program, the only way to get this information on

WAITS WAITS is a heavily modified variant of Digital Equipment Corporation's Monitor operating system (later renamed to, and better known as, " TOPS-10") for the PDP-6 and PDP-10 mainframe computers, used at the Stanford Artificial Intelligence Labor ...

was with a WHO program that showed IDs and terminal line numbers (the server's internal number of the communication line over which the user's terminal is connected) for logged-in users. In reference to the name FINGER, Les Earnest, wrote that he saw users of the WAITS

time-sharing In computing, time-sharing is the Concurrency (computer science), concurrent sharing of a computing resource among many tasks or users by giving each Process (computing), task or User (computing), user a small slice of CPU time, processing time. ...

system run their fingers down the output of the WHO command.

Finger user information protocol

The finger

daemon A demon is a malevolent supernatural being, evil spirit or fiend in religion, occultism, literature, fiction, mythology and folklore. Demon, daemon or dæmon may also refer to: Entertainment Fictional entities * Daemon (G.I. Joe), a character ...

runs on TCP port 79. The client will (in the case of remote hosts) open a connection to port 79. An RUIP (Remote User Information Program) is started on the remote end of the connection to process the request. The local host sends the RUIP 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 to close 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 or in.fingerd (for ''finger

''), 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 A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user ...

. The program would supply information such as whether a user is currently logged-on,

e-mail address An email address identifies an email box to which messages are delivered. While early messaging systems used a variety of formats for addressing, today, email addresses follow a set of specific rules originally standardized by the Internet Engineeri ...

, 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 A home directory is a directory (file systems), file system directory on a multi-user operating system containing computer file, files for a given user (computing), user of the system. The specifics of the home directory (such as its name and loc ...

. Often this file (maintained by the user) contains either useful information about the user's current activities, similar to

micro-blogging Microblogging is a form of blogging using short posts without titles known as microposts or status updates. Microblogs "allow users to exchange small elements of content such as short sentences, individual images, or video links", which may be the ...

, or alternatively all manner of

humor Humour ( Commonwealth English) or humor (American English) is the tendency of experiences to provoke laughter and provide amusement. The term derives from the humoral medicine of the ancient Greeks, which taught that the balance of fluids i ...

Security concerns

Supplying such detailed information as e-mail addresses and full names was considered acceptable and convenient in the early days of networking, but later was considered questionable for privacy and security reasons. Finger information has been used by

hacker A hacker is a person skilled in information technology who achieves goals and solves problems by non-standard means. The term has become associated in popular culture with a security hackersomeone with knowledge of bug (computing), bugs or exp ...

s as a way to initiate a social engineering attack on a company's computer security system. By using a finger client to get a list of a company's employee names, email addresses, phone numbers, and so on, a hacker can call or email someone at a company requesting information while posing as another employee. The finger

has also had several exploitable security holes crackers have used to break into systems. For example, in 1988 the

Morris worm The Morris worm or Internet worm of November 2, 1988, is one of the oldest computer worms distributed via the Internet, and the first to gain significant mainstream media attention. It resulted in the first felony conviction in the US under the ...

exploited an overflow vulnerability in fingerd (among others) to spread. For these reasons, by the late 1990s the vast majority of sites on the Internet no longer offered the service.

Application support

It is implemented on

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

(like

macOS macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

Unix-like A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Uni ...

systems (like

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

and

FreeBSD FreeBSD is a free-software Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable ...

), and current versions of

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

(finger.exe command). Other software has finger support: *

ELinks ELinks is a free text-based web browser for Linux, DOS, and Windows operating systems. It began in late 2001 as an experimental fork by Petr Baudiš of the Links Web browser, hence the E in the name. Since then, the E has come to stand for En ...

Lynx A lynx ( ; : lynx or lynxes) is any of the four wikt:extant, extant species (the Canada lynx, Iberian lynx, Eurasian lynx and the bobcat) within the medium-sized wild Felidae, cat genus ''Lynx''. The name originated in Middle Engl ...

Minuet A minuet (; also spelled menuet) is a social dance of French origin for two people, usually written in time. The English word was adapted from the Italian ''minuetto'' and the French ''menuet''. The term also describes the musical form tha ...

*Kristall *Lagrange

References

{{DEFAULTSORT:Finger Protocol Internet protocols Internet Standards OS/2 commands Unix user management and support-related utilities Unix network-related software Windows administration 1977 software

Name/Finger protocol

Finger user information protocol

Security concerns

Application support

See also

References