Manual for new users FreakNet Medialab, Catania -------------------------- This text was composed by asbesto@freaknet.org, with some precious contributions written by vinx@freaknet.org, martin@freaknet.org, and by some of the hackers from the Florence Linux User Group (FLUG). It was translated into English from the original Italian by martin. Minimal bibliography: : A.Banahan, T.Rutter, Unix - The Book ------------------------------------------------------------ Introduction ------------ If you have this document in your hands, you've probably just been given a mail address on the Freaknet Medialab network. If that's not the case, get one assigned to you as soon as you can: electronic communication is an extremely powerful way to exchange information between people and between different realities (antagonisto or not) throughout the whole world: I hope that as time goes by you will come to realise this for yourself, learning to use this powerful tool to the full. If you haven't yet got your own personal access to our network, don't worry, you can still study this document and try things out as much as you want. Do you know how to read? Great! In that case you have a very good chance of becoming a good user of our Linux system. Our network of computers works thanks to a completely free system of programs, developed by thousands of programmers the world over. This set of programs allows the computer to work and is called the "Operating System". Its name is Linux. Linux was originally written by a Finnish programmer (Linus Torvalds) who decided to share his creation with the the Hacker community of the whole world, thereby giving everybody the possibility to "get their hand on it", improving it continually and writing new programs. This beatiful work is still going on, and almost all Linux programs follow the same philosophy of distributing information freely, which is one of the basic tenets of Hackers. On this subject, the Florence Linux User Group has found better words than mine, writing: "Open source (or Free Software) is a way of thinking about software that was born many years ago, mostly due to Richard Stallman. A program is seen like a poem or a mathematical theorem, as an intellectual work that, as such, should be free to use. People who develop Free Software place their work under certain licences that allow other programmers and users to freely use, copy and modify the program, whose source code is also supplied." More precisely, we can say that Linux is a dialect of UNIX. To avoid confusion, from now on we'll say that Linux is the same as UNIX, they are practically the same thing. If you want to know more, have a chat with one of the people at the Medialab: those strange creatures are there specifically to explain everything you want to know: take advantage of them! The best way to learn to use Linux is simply: try, try and try again. and the best fuel for learning to run with us in our little digital trazzera is simply: CURIOSITY Don't be afraid to sit down at one of the terminals of our network, write with the keyboard, try commands out, read documents etcetera: you cannot in any way do any damage, so just try to have fun! The most common error made by beginners is to sit down in front of the computer, and to turn IMMEDIATELY to one fo the gurus and ask unhappily: "I don't understand a thing! What must I do?" Tha main thing that a beginner MUST always do is to CAREFULLY READ WHAT'S WRITTE ON THE SCREEN. In fact, very often it's enough to read what's written there to know what to do. For example, reading the bulletin of the social centres is very simple and it's clearly written what to do in the screen of any of our terminals. You do know how to read, don't you? Knowing English, you'll be at a great advantage: in fact many of the commands are English words whose meaning tells you straight away what the command is for. What is this strange network of glowing boxes? ---------------------------------------------- The FreakNet MediaLab network is a collection of computers, each of which has a name. Some of these computer perform specific tasks, while others are simple terminals used to access the rest of the network. The names of the computers are almost always the names of artificial satellites, mostly russian. On the ground floor we have Skylab (on the bar), Mir and Mariner in the main hall, and Hubble at the entrance to the printing press room. On the first floor are other computers that are used to manage networked services, such as electronic mail and information bulletins and more. THe main computer of the network is "medialab". On this computer is all the information beloging to the users of teh network, their electronic mail, their work areas and more. Medialab manages the network, checks who logs into the network and offers electronic mail to other users of medialab and to the rest of the Internet. Finding a terminal ------------------ The first thing to do to start working with our network is to find a terminal: an electronic device with a screen like the one the TV has, and a keyboard that is similar to the one on a typewriter. At the moment (July 1999) at Auro there are four terminals available to the public in the first room of the Centre, that can be used when the centre is open, plus a similar number in the Freaknet laboratory on the first floor, available when "the technicians" are present. At Auro there are two different types of terminal: o the simple teminals used to gain access to the services of "medialab", tha main computer of the FreakNet network, also known as "serial terminals". One of these is on the ground floor at the entrance to the printing press room, and it is called "Hubble" (after the famous orbiting telescope) o small independent computers, known as "satellites", that can run programs on their own, as well as being used to gain access to the wider range of public services on "medialab". Some of these are: Skylab, on the bar, Mir and Mariner, on the two sides of the central column in the main hall. First, let's see how to use a simple terminal, then we'll move on to using the satellites, which are not much different. Switching the terminal on ------------------------- If the picture on the screen is all black, press the ENTER key on the keyboard (also known as INVIO on Italian keyboards, or marked with a left-pointing arrow with a bent tail <--' ). If nothing appears on the screen, it might be that the monitor (the part of the terminal that looks like a TV) is off. If no lights are on in the frame of the screen, search the bottom of the frame, the sides and the back for a switch or a press button marked "0 - 1" and make sure it is pressed in (or switched towards "1"). If at this point it doesn't turn on, seek help from someone who knows more about it than you, or find another terminal. Gaining access to the system ---------------------------- Every computer on the network presents a welcome screen, which shows the name of the computer a some useful information. At the bottom of the screen it says "login:" followed by a flashing cursor (a little white rectangle that flashes on and off). Every time you want to use a networked service, like for example electronic mail, you must "make yourself known" to the system. Here's the difference we hinted at earlier, between the "satellite" computers and the "simple terminals". The simple terminals are connected directly to medialab, while the satellites are independent machines that to which we have to explain that we want to use the services on Medialab. In fact, to use the electronic mail services you need to connect to "medialab", tha main computer of the network. If you are using a simple terminal, the coloured welcome screen will show the name of the computer you are connected to, in this case Medialab. If this is the case, you can skip a few lines of this document, to the part marked with (##########). If you are using a satellite computer, the usual box will appear with the name of the sattelite that you are using in it (Mir, Skylab, Mariner). In this case you must persuade it to connect you to medialab to be able to make use of its services. To do this, it is enough to write "medialab" at the login, and then press the ENTER key. * Remember that, after every command of piece of information that you * give to the computer, you MUST press the "ENTER" key, otherwise the * computer will sit there waiting for you to confirm the command you * have given (by pressing ENTER). * * Normally, the computer will not carry out anything you have typed in * until you press the ENTER key, which tells the system that the line * you have typed is complete. * * Sometimes beginners forget to do this, type in a line and then stop, * waiting proudly for the results that they will never see. This is * because they have forgotten to press the enter key. You won't do that, * will you? If, for eaxample, you're using the satellite Skylab, on the bar, you'll get a screenful looking something like: ------------------------------------------------------------------ Freak net MediaLab Skylab 192.168.1.61 Freak Net Media Lab Network Anonymous FTP available I tentativi di HACKING su questo computer sono INCORAGGIATI !!! :) Accesso libero : al login scrivere 'luther', password : 'luther' Per leggere il bollettino : al login scrivere 'boll' Welcome to Linux 2.0.30/i386 #3 Tue Jun 24 03:49:52 CDT 1997 skylab login: medialab medialab login: ------------------------------------------------------------------ (##########) The message "medialab login" means that at this moment you are connected to the central computer of the network, ans you can therefore gain access with your name and your personal password. In fact, you must always present yourself to "medialab" to be able to use the electronic mail service. To do this, you need to "log in", typing the name you chose to register under. If you don't have your own personal "login" yet, you can use the free-for-all name "luther". Type "luther" (without the quotation marks!) and press ENTER. skylab login: luther Password: Now you will be asked for your "password", which is a secret word known only to you. This is used by the computer to tell the various people who use the computer apart, so that each person has their own work area which is separate from everybody else's, and is protected against accidentally being erased or read by other people. If you don't yet have your own personal login and you have put in "luther", you can give luther's password, which is also "luther". So type "luther" again (obviously, without the quotation marks") and press ENTER. NOTE: while you are typing the password, what you type does not appear on the screen. This is normal! If someone were standing behind you at that moment, they would be able to read your password, and then they could enter the system pretending to be you, read your electronic mail, play tricks on you and so on... :) Once you have given your login and your password, and the system recognises you and gives you a "welcome" message, showing you some "useful" information (which you would do well to read) and gives you the "system prompt", which is a line of text which means that the computer is ready to recieve your commands. Normally the system prompt looks like this: yourname@medialab:~$ or, if you entered with luther's login and password, the prompt will be luther@medialab:~$ At this point the computer is ready to receive your commands. A simple command: echo ---------------------- "Echo" repeats whatever you typed. Try typing this on a terminal - it will encourage you if you're feeing a bit down and need some comfort. echo how are you Don't forget the ENTER key! The system will reply: how are you Isn't that cute? I've finished working. Now what? -------------------------------- An EXTREMELY IMPORTANT command that you must remember is the one to say that you have finished working, and that you are going away. That command is "exit". When you have to go, REMEMBER ALWAYS TO GIVE the command "exit" to the system prompt. If you don't do it, and you go away without giving it, your system prompr will remain on the terminal, and someone else will be able to gain access to your private electronic mail, delete your work, play tricks on you, etcetera. A couple of words about the terminal you are using -------------------------------------------------- The terminal is your only means of communication with the system; it's what you use to give your commands, to check the results of them and to ponder over the relics of dead programs. The terminal is the eyes and ears of your dialogue with the Linux operating system; you should get to know it well. What should we say about typing? -------------------------------- You might be one of those lucky people who never make mistakes, a member of that select group that sits at the terminal all day with their fingers flying over the keys without ever touching the wrong one. Or you might be the opposite, a normal human being - the sort who thinks that carving inscriptions on stone seems easy compared to typing something on a computer. UNIX (that is, Linux) has a place for you too. Unfortunately, one of the most variable characteristics of UNIX systems is the way in which they choose to handle their terminals. One of the sore points is the way you cancel typing errors. Making typing errors disappear isn't particularly difficult on most terminals - you cancel what you typed with the backspace key, which is usually the one above the ENTER key, marked with a left-pointing arrow <-- This button cancels the characters that are on the LEFT of the flashing cursor. So if, for example, we write echo i drink a lot of water_ without pressing ENTER, and we want to cancel "shit", we just have to press the backspace key 5 times, which will leave this: echo i drink a lot of _ and at this point we can complete our phrase writing whatever our favourite liquid is instead of "water". Try it out! Another way of cancelling errors is to use the arrow keys and the "CANC" key, which is normally on the RIGHT of the ENTER key, and it's a button with "Canc" or "Del" written on it. For example, if we write echo yesterday evening i found a box of sweets without pressing ENTER, and we wanted to cancel "evening" and put "night" instead, we should go back using the left arrow key to position the cursor at the start of the word "evening", press the CANC (or Del) key 7 times, and then type "night". Have a go! Sometimes, on some terminals, or using certain programs, you will notice that the backspace key doesn't really cancel the characters to the left of the cursor, but erases the characters on its right instead. This often happens on "simple" terminals, because the way they work is slightly different from the satellite computer. But it's not a problem! With a little imagination and by trying the CANC, DEL and backspace keys out, you'll soon discover what they do and you'll soon know how to adapt to the various differences. Make a note of these keys, that way you won't forget them! Some possibile problems with the terminals and their solutions -------------------------------------------------------------- Problem: When I typed "luther", "LUTHER" appeared on the screen. Then when I pressed "Enter", it asked me PASSWORD: instead of Password:, and when I put the password in, it said "LOGIN INCORRECT". It won't let me in, and keeps coming back and asking me "MEDIALAB LOGIN:" all in capital letters! Has it gone stupid? Reason: The keyboard of the terminal is sending everything in capital letters instead of little letters. There may be two reasons: 1) "Caps Lock" has been pressed in the past, which sets the keyboard so that everything you type come out in capital letters. Usually that key is on the far left of the keyboard, on the third row of keys, and is marked with a padlock or with the legend "Caps Lock". This key works like some light switches, you press it once and it turns on, you press it again and it turns off, and there's probably a tiny light on the keyboard in the top right corner, which is also marked "Caps Lock" which shows whether this function is active or not. If the light is on, press the "Caps Lock" key, and it will turn off, going back to the usual lower case letters. 2) The keyboard has been filled with beer, and one of the "Shift" keys (in the lower left and right corners of the keyboard, marked with a large arrow pointing up) has got stuck down. (This often happens to Skylab). These keys are different from the "Caps Lock" key; they make capital letters come out as long as you hold one of them pressed down, and go back to normal lower case letters as soon as you let go of them. Try to free up the key in question to make it come back up. ritornare su. But the problem is not yet completely solved. Unfortunately, when you reply to "login:" with just capital letters, Linux assumes that you are using an ancient terminal that only HAS capital letters. To make it go back to using the usual lower case letters, you must restart the login procedure, which you do like this: o If the last line of the screen asks for "PASSWORD:", press the "Enter" key to get "LOGIN:" again. o At "LOGIN:", reply with a sequence of keys that is called "Control-D": press down the "Ctrl" key, and while you are holding it down, prod the "D" key, then let go of the "Ctrl" key. This sequence terminates the current login procedure (which has gone wrong!) and brings you back to the initial coloured screen. A few words about your personal password ---------------------------------------- Linux is like most multiuser systems as far as user names and passwords are concernced. The user names are used to identify the individual users of the system and are related to the ideas of privileges and protection - which users can gain access to which files and which users can user which commands. Since (as you will learn) UNIX commands themselves are memorized in files, the whole question of who is allowed to do what is decided by the filestore and you should expect to find out how it works. Obviously, there's no point having a system to protect its users from each other if they only need to know each other's names to impersonate their victims. To prevent this, each user has a secret password which they must give when they try to gain access to the system. If they give the wrong password, they wonw't be allowed into the system. UNIX (Linux) lets its users change their passwords to personalise them; some very common passwords are the names of people's idols, of people they love, telephone numbers and this kind of thing. Unfortunately they are easy to guess, and are the first thing that will be tried by people trying to find out what your password is. Your choice of password is up to you, and if you are interested in security, here are some suggestions: - choose unusual passwords - use a mixture of capital and lower case letters - include digits and punctuation characters - NEVER let anyone watch you while you log in - change your password regularly - keep an eye out for signs of intrusion Why all these rules? It's simple. An unusual password is difficult to guess when they are trying to breach your defences. Mixed case, digits and punctuation in a password make it extremely unusual and make it hard for people to tell what you are typing while you log in. Gaining access to the system under the eyes of others is dangerous, since you offer them a good chance of finding out the first few characters of your password. This will help them enormously if they are resorting to the "brute force" method to break your password, which consists in trying every possibile password one after the other. Even if someone does discover your password, probably after having spent a huge amount of time and effort on the problem, they will have to start all over again as soon as you change it. It's also good for them to know that you change it regularly, because they might give up straight away, since after the time it takes to find it out, they'd find themselves with your password from the day before, which would be useless to them. How can you tell that someone has discovered your password? ----------------------------------------------------------- UNIX systems, and therefore also Linux, normally keep a record of who has entered the system and when, so you can look every now and then and see if you seem to have used the system when you weren't (as far as you know) anywhere near a terminal. This information is given to you as soon as you log into the system. Among the various useful pieces of information that are presented to you after you put in your user name and password, there's a line that says, for example Last login: Tue Sep 21 18:57:42 on ttyp3 from skylab.freaknet.org This means: The last time that you entered was on Tuesday the 21st of September at 18:57, from the computer Skylab. If this doesn't corrispond to the truth (for example, if you were at elsewhere at that time on the 21st of September), this means that someone else entered into the system pretending to be you. Ask one of the gurus for further explanations. There are some truly awful methods used by the champion password thieves, who tend to consider it as a sort of intellectual challenge: for them, the security system has been built to be broken. Some of these methods are so hard to beat that their names are only ever mentioned in closed rooms at the dead of night, and the secrets are passed between the initiates like a kind of pagan ritual. For the moment, we have no intention of hinting at these techniques, which are already powerful enough in the hand of the few who can dream them up for themselves, without needing us to spread them around. This is in line with the well-known military security principle: "the longer your enemies have to think about how to attack you, the less time they have to do it." We would just like to underline that it is not just UNIX that is vulnerable to this kind of attack; all operating systems that use a combination of username and password are equally at risk. I want to change my password! ----------------------------- Let's spend some time on changing your password. The preceding paragraphs will probably have scared you and that's not really a bad thing. Decide what password you would like, and make sure you able to remember it. It is very troublesome if you forget it, and the number of forgetful people who manage to forget their passowrd is a constant source of amusement for the people who have to sort it out for them. The command to change your password is called "passwd". It is an unusual command because it interacts with you. Most UNIX commands prefer not to ask you any questions. To call up "passwd", type (after hacing logged into the system): passwd This will make passwd ask you your old password; it's making sure you really are who you claim to be, in case some joker tries to change your password should you leave your terminal connected by mistake. If it's correct it will ask you for the new password, and will not echo it on the screen, then you will be asked to type it again for safety. If both of the new password are the same, passwd will change your password to whatever you typed. Passwd tried hard to make you choose a password that is in line with the simple security rules we mentioned previously, and if it thinks your new password is too simple, it will refuse to accept it. Try again, using a more complex password. Here is a practical example, and while you're using it, remember that the passwords you type will not appear on the screen. ienzo@medialab:~$ passwd Changing password for ienzo Old password: Incorrect password for ienzo. The password for ienzo is unchanged. ienzo@medialab:~$ In this case, someone has tried to change the password for the user "ienzo", but has not supplied the correct password. ienzo@medialab:~$ passwd Changing password for ienzo Old password: Enter the new password (minimum of 5, maximum of 8 characters) Please use a combination of upper and lower case letters and numbers. New password: Re-enter new password: Password changed. ienzo@medialab:~$ In this example, instead, ienzo has changed his old passwd for a new one. ------------------------------------------------------------------------ Electronic mail --------------- Your electronic mail address is: yourname@freaknet.org To exchange messages with users in Internet, obviously you must give them your electronic mail address :) There are two electronic mail programs: "mail" and "pine". "mail" is a very simple program athat is very eaasy to use, and it's convenient for writing electronic mail. Let's see how! To write a message to another user of medialab, for example to "asbesto", you just write "mail asbesto" and press Enter. yourname@medialab:~$ mail asbesto Subject: The "mail" program asks you the "Subject:" of your message to "asbesto" (that is, what you want to talk to asbesto about). Obviously, you can type whatever you want, and press ENTER. The cursor will go down to the following line, the blank one, and at this point you can write whatever you want, that is to say, your message. To end your message, you just need to give a "." (full stop) on a line by itself. For example, this is the screenful that you'll get if you write a generic message to asbesto. --------------------------------------------------- yourname@medialab:~$ mail asbesto Subject: Hi, how are you? I've realised that this system is very powerful, and at last I can write to people and get their news about how things are going where they are. This is all wonderful! bye, see you soon . Cc: ---------------------------------------------------- As you can see above, after you give the "." on an empty line, a message appears saying "Cc:", which means "Carbon Copy". This is useful if you want to send a copy of the same message to other people at the same time. You can reply to "Cc:" with the user name sof other peopel whi use email, such as "luther", "shining" and others. If you only want to write to one person (in this case just asbesto, since we gave the command "mail asbesto"), just press Enter, your message will be sent automatically, and you'll get the usual system prompt back: Cc: yourname@medialab:~$ That's anough about the "mail" program, which as we have seen, is very simple and lets you send message easily to other users of electronic mail. Internet mail ============= For mail to other people on the internet, it's better to use the program "pine". Pine is the program that allows you to read and write electronic mail, both to other users on medialab and on the Internet (ie in the whole world!) Let's see step by step how you can perform the following operations: 1) Write an email message 2) Read the email you have received 3) Crate a file with your own personalised signature 4) Change the name from you write messages Okay, let's start with the basics. Once you have logged in to medialab, with your own user name and password, you just have to type "pine" and press Enter to start the mail program up. yourname@medialab:~$ pine Once Pine has started up, it will show you a screen showing various things that you can do. The one we are interested in first of all is C, COMPOSE MESSAGE. (1) COMPOSING A MESSAGE Move up and down with the arrow keys onto COMPOSE and press Enter (or just press 'C' directly) to go into the section for writing an email. At this point you are presented with a new page in which you must do the following things (you can move up and down with the arrow keys) a) "To:" is the internet mail adddress of the person you want to write to. Just type their internet email address, which will some combination of letters, digits, dots and an @ sign, or just the user name of someone on medialab. b) On the second line (identified by "Cc:") you can add other addresses to which the same message will be sent at the same time, separating the addresses with commas E.g.: vinx@freaknet.org, asbesto@freaknet.org, avex@freaknet.org If the addresses have been put in correctly separated by commas, the program will display the addresses each on its own line when you move down to the next field. If you just put the name of another user of medialab, this will be "completed" automtically, adding "@freaknet.org" to it: this is because pine has been programmed to work automatically for mail on the Internet. d) "Attchmnt:" is useful if you want to send a file or document together with the message (for example, a picture, a photograph, a program, a virus :); you just have to type the name of the file that you want to send along with the mail. e) In the last field, "Subject:", you should insert a one-line summary of the email that youäre writing. It's a good habit to put some relevant words here, because people who receive a lot of email look at the subjects first, and decide from them which messages they're going to read first and which later. It's the "title" of the message. f) At this point, still moving up and down with the arrow keys, you get to the main part of the screen where you can type the body of the email. Once you've finished your message you are various things you can do. Fundamentally, we are interested in SENDING the message or NOT SENDING it. To SEND the message when you've finished, you need to press CTRL X (while holding the CTRL key down, press "X" once). The program calls this "Send", and it explains this on the bar at the bottom of the screen, which explains various commands. The one we are using is this one \ | \|/ ^G Get Help ^X Send ^R Rich Hdr ^Y PrvPg/Top ^K Cut Line ^O Postpone ^C Cancel ^D Del Char ^J Attach ^V NxtPg/End ^U UnDel Line^T To Files To ABORT the message that you've written (if you have changed your mind and don't want to send it any more) you need to hold down CTRL and press C. After you press one of these combinations, you'll be asked to press Y (yes) to confirm the action, or N (no) to say "No, not yet". Often, after you give a command to Pine like CTRL-X or CTRL-C, you'll be asked to confirm it: to reply just press Y (yes) or N (no). (2) READING MESSAGES To read the message you have received, the option you are interested in is "I", MESSAGE INDEX: using the arrow keys to move up and down and then pressing "Enter", or simply pressing "I", you enter into a screenful in which you can see a list of the messages you have received. If there are any messages there, you can move between them with the arrow keys and by pressing "Enter" it will be possible to read the full text of each one. At this point, while you a re reading a messgage, you can decide to REPLY to it, DELETE it or FORWARD IT TO SOMEONE ELSE. a) REPLY: press 'R' and you'll be asked whether you want to reply to eveyone mentioned in the message; it's normal to say NO. Press the N (or the Y) and you'll find yourself in the writing phase we mentioned earlier. It's worth noting that the phrases written by the person who sent you the message are highlighted by a character '>' at the start of each line. This is so that you can have a reference to what you are talking about. With time and experience you will understand :) b) DELETE the message, by pressing 'D' and maybe getting it back again by pressing 'U' (UNDELETE) if you change your mind and don't want to delete ir any more. c) FORWARD the message to someone else, by pressing 'F'. In this case it'll be like writing a new message, but with the text alreadz written for you. To get out of Pine, from the main menu just press the Q (QUIT) key or move onto QUIT with the arrow keys and press ENTER. If you've finished working, remember to give the command "exit"! -------------------------------------------------------------------- How can I get into FreakNet MediaLab from home? ----------------------------------------------- You will need internet access from home. If you are using Linux or Windows, you can open up a "Shell" or an "MSDOS Prompt" and type: telnet medialab.freaknet.org or you can visit our Web page at the same address, where there are three other ways to logging in to MediaLab over the internet. Once you have connected, as if by magic the FreakNet access page will appear on your screen, you can to type your login name and your password, and you'll be able to use all the services of our network from the comfort of your own home. ------------------------------------------------------------------- That's all for now. Thankyou for reading this document! asbesto, 21/9/99 / martin 10/2/04