FFFiiinnngggeeerrr --- AAA UUUssseeerrr IIInnnfffooorrrmmmaaattti Michael T. Horne, KA7AXD _1_9_5_9_5 _S_W _M_a_r_t_i_n _S_t _A_l_o_h_a, _O_R _9_7_0_0_7 _A_B_S_T_R_A_C_T With the recent explosion in amateur TCP/IP activity, primarily made possible by the KA9Q Internet Package, the need has arisen for a use vice. Users on the amateur network can now retrieve important information about other amateurs through the use of a new application called _f_i_n_g_e_r. This paper describes fing source for information retrieval in the amateur net- working world. 111... BBBaaaccckkkgggrrrooouuunnnddd ten primarily by Phil Karn with contributions from others, ama- teurs have been able to build computer networks based around their own personal computers. The package offers the amateur a complete system receiving mail, remote computer log-in facilities, and simple keyboard-to-keyboard conversations, far more advanced and power- ful than a standard Terminal Node Controller. What has been lacking is the m vice, allowing amateurs to exchange basic, yet important, infor- mation about each other. In the commercial world of networking and UNIX computers, such an information service exists. This service is calle Finger has its origins at the University of California at Berkeley, written as a means for users of the UNIX system to retrieve information about other UNIX users [1]. A user on the system could telephone number, what project he was working on, and other use- ful facts. Other system dependent information, such as whether or not he was logged on and what terminal he was using, was returned to th this information is directly applicable to the amateur network- ing world, but something similar to this could be very useful. 222... FFFiiinnngggeeerrr Amateurs have historically been curious about their fellow hobbyists. Most conversations you listen to on the HF bands consist of an exchange of name, location, and other personal in other for this same information in order to get to know each other. Up until now, one has had to ask the amateur personally for the information, or lookup the information in a Callbook. Seeing the nee service, I proceeded to write an application for the KA9Q pack- age that would allow amateurs to lookup information when they need it. The finger application I wrote allows amateurs using the information about themselves. Users can now retrieve such important facts as name, address, and telephone number, QSL information, station equipment used, projects currently under- taken, and man limit to what information can be exchanged! At the same time, amateurs have complete control over what information about them- selves can be retrieved by other hams. As our network expands, this applicatio other quickly and efficiently. 333... HHHooowww tttooo UUUssseee FFFiiinnngggeeerrr Th following three ways: 1) finger user 2) finger user@host 3) finger @host UUUssseeerrr is the user's name you wish to query and hhhooossst of the host, or computer, that the user is at. The first form of the command is used to find out informa- tion about a user at the local host, namely your own system. It is useful for testing finger on a ning. The second form of the command is used to find out infor- mation about a user at a remote host. If you don't know the name of a particular user at a remote host, you can use the third form of th users currently known on the remote computer. To enable the finger server on your system so that others may query the users on your system, you must type `start finger'. If you don't start the f other systems will not be able to finger users on your system. 444... TTThhheee FFFiiinnngggeeerrr IIInnnfffooo By now you are probably wondering how the computer knows information about a particular user. In order to provide a cer- tain amount of privacy, _f_i_n_g_e_r _w_i_l_l _o_n_l_y _r_e_t_u_r_n _i _t_h_e _u_s_e_r _p_r_o_v_i_d_e_s _i_n _a _f_i_l_e. Each user maintains a text file of information. The local user's text file is returned to the remote user each time the local us does not want to have information about himself sent to other systems trying to finger him, he simply does not create the file. On an MS-DOS system running net, all of the finger files nized by the finger system must create a uuussseeerrr...tttxxxttt file in the finger directory. For example, on KA7AYF's system he may have two users; ` these two users, he must create two text files: \finger\glen.txt and \finger\lisa.txt . What you put in the finger information files is completely up to you, but here are some guidelines: 1) address, and telephone number in your finger file so other hams can contact you. 2) You might add information such as your license class, sta- tion configuration, and occupation. you are currently working on. This will provide helpful information for others who have similar interests. 4) Remember that the longer your finger file is, the longer it may take to transfe 555... AAAnnn EEExxxaaammmpppllleee FFFiiinnngggeeerrr SSSeeessssssii On my system, I have two users; `mike' and `teresa'. If someone fingers mike@ka7axd.ampr, it might look something like this: net> fffiiinnng SYN sent Established [ka7axd.ampr] Hello and welcome to ka7axd.ampr running the KA9Q TCP/IP code! User: mike (KA7AXD) Real Name: Michael T. Horne Address: Michael T. Horne 19595 SW Martin Beaverton, OR 97007 (503) 591 - 0488 System: IBM AT Clone MFJ TNC2 KISS TNC Occupation: Hardware/Software Engineer 2710 Spectrum Analyzer Group Tektronix, Inc. Close wait Last ACK Closed (Normal) net> 66 Finger uses the well known port number 79 using TCP. When fingering a remote host, a socket is opened to the remote host using port 79. Once established, the client sends the name of the user on th return/line feed sequence if system information is desired (such as a list of known users). The server attempts to find a file in the finger database directory under the name user.txt. If it fails, it retu with that name is known on the remote system, then closes the socket. If it succeeds, the server returns the contents of the user.txt file to the client, then closes the socket. If the form `finger us the local host, and program flow follows that described above. 777... SSSuuummmmmmaaarrryyy The finger application under the KA9Q Internet Pac vides amateurs with a simple, but powerful, user information lookup service. Amateurs can use the application to quickly find important information about other amateurs on the network. As our network e and may eventually serve as a primary resource for obtaining the information amateurs need. RRReeefffeeerrreeennnccceee 1. _P_r_o_g_r_a_m_m_e_r_'_s _M_a_n_u_a_l, University of California, Berkeley, 1986.