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Spring term 2000
Using Linux at the ITU data bars
Department of Information Technology, Technical University of Denmark
Michael R. Hansen, Jørgen Arendt Jensen, Morten Olsen and Hans Rischel
The IT University of Copenhagen
Niels Hallenberg, Anders Steen Rasmussen and Peter Sestoft
These notes explain how to use Linux at the ITU data bars at ITU.
ITU has many data bars located in the buildings at Glentevej 65 and Glentevej 67. At Glentevej 65,
we have a data bar in room 0.05. At Glentevej 67, we
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1 Logging in The access to the computers in the ITU data bar system requires a user id (login) and a password. You will get your user id and password on a sheet of paper which is issued by the ITU administration. Your user id (login) and e-mail address, minus@itu.dk, are the same, that is, with loginnh your e-mail address isnh@itu.dk. You start a session by logging in at a PC and you terminate the session by logging out. Logging in comprises the following steps: 1. If the PC is running Windows,
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2 Executing commands via the button-bar The desktop environment consists of a button-bar to the left and a task-bar at the right of the button-bar. The button-bar provides an easy way for executing some commonly used commands (programs). The picture at the right shows the button-bar. A button is activated by clicking on the button (moving the cursor to the button and pressing the left mouse key): K opens a menu similar to the start button in Windows. From the menu you can start various applicati
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close button system menu button maximise button title bar sticky button minimise button Figure 1: A window 3 Windows and icons A window displays a separate dialogue with the operator. A window in a data bar has the general lay-out as shown in Figure 1, with a system menu button, a sticky button, a title bar, a minimise button, a maximise button, and a close button located at the top of the window. A window is selected (and gets into the foreground) when the the left mouse key is clic
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Figure 2: A task bar 4 Printing Printers are located in various rooms; use the URLhttp://localhost:631/printers to see which printers are available and where they are located. You can also choose the item “Printere” in the menu found by pressing the [Book and ?] button on the button-bar, see Section 2. A printer is namedpXXX, whereXXX is the room-number where you find it (e.g., printerp165 is located in room 1.65). We also have copy machines that can be used as printers. They are namedcXXX. Curre
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Figure 3: The Emacs editor with an SML program Figure 4: The SML session window Meta- means: hold down the “Alt” or “Alt function” key and press the key . Ctrl- means: hold down the “Ctrl” key and press the key . This a brief step-by-step guide to editing programs. 1. Start Emacs by use of the emacs button in the button-bar. An empty Emacs window called *scratch* appears. Move the cursor to the Emacs window and click the left mouse button to select this window. Do not type your program i
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This creates an SML session, and loads the program into the SML session. 6. TypeCtrl-c Ctrl-s to see the output from the SML session. The SML session will be in a new window named mosml, as in Figure 4 on page 6. 7. Resize and move the Emacs window (as described in Section 3) to make the two Emacs buffers gcd.sml and*mosml* larger. You can left-click on the buffer you want active. 8. If the program has syntax errors or type errors, the SML session prints messages about them. Use Ctrl-c ‘ to move
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id type value exception compile string -> unit compile unit ( ) Fail load string -> unit Load unit and any units it needs Fail loadOne string -> unit Load unit only Fail printVal ’a -> ’a Print value onstdOut printDepth int ref Limit printed data depth printLength int ref Limit printed list and vector length quit unit -> unit Quit the interactive SML system system string -> unit Execute operating system command use string -> unit Include file in program verbose bool ref Pe
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while the fileHelloWorld.java is specified by a path using the parent directory symbol “..”: (’ )* ,+ - - . / .! 0-!1*$32 4 504 .. Other users may read the fileex1.tex by using a path containing the user name preceded by a tilde character (unless reading by other users has been prohibited): ,9 : 9 8 ! * ! #" $&%0 ˜ 687 Notice, that in Linux the file system is case sensitive, that is, the file nameDBD anddbd refers to two different files. To change current directory usecd. To ge
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A Figure 6: A LT X buffer in Emacs E \usepackage[latin1]{inputenc} \begin{document} This document is type set with \LaTeX. \end{document} To compile the document typeCtrl+c Ctrl+c and answer the questions. If errors occur, then type Ctrl+c Ctrl+l to view the compiler messages. Correct the errors and type Ctrl+c Ctrl+c again. On succesful compilation you can view the document typing Ctrl+c Ctrl+c again and pressreturn. 10 Some useful UNIX commands The commands described in this section are execut
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Changing password At the beginning you get a password which has been generated automatically. This must be changed to one you invent yourself. Creating and removing directories cd move to another directory. mkdir create new directory. rmdir remove directory. pwd show path to current directory Using files cp copy file chmod change protection of file. find find files. locate find files based on a database – much faster thanfind. less display contents of file. ls list attributes of file(s). mv rename file. r
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Manipulation of text files diff compares two files and reports the differences. grep search file for pattern (regular expression). sort sorts textfiles. head prints first 10 lines of file. tail prints (surprise) last 10 lines of file. a2ps “pretty-prints” ASCII files on a printer – actually a PostScript file i generated and sent to a printer. wc counts lines/words/letters in a file. Redirection of input or output To redirect the input or output for a program invoked by a command you use< and>. For example
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KDE - The K Desktop Enviroment This is one of the most mature and full featured desktops available for Linux. The developers of KDE seem to have been inspired by MS Windows quite a bit, and KDE is nauseatingly alike it. Of course if you use MS Windows at home, you should feel quite at home in KDE. Using so called “themes” you can change the look of windows, borders, backgrounds ect., giving opportunity for countless hours of fun doing “window shopping”. KDE is the default window manager in the d
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User-guides and HOWTO’s can be found onhttp://howto.linuxberg.com General computer and Linux related news onhttp://www.slashdot.org Danish user groups The Skane-Sjællands ˚ Linux User Group (SSLUG) has a lot of material on their web-site. They also run mailing-lists/newsgroups where new-bies can get friendly help with all aspects of Linux. They also maintain a very nice user-guide, it is available on their website. SSLUG -http://www.sslug.dk “Linux - Friheden til at vælge”http://www.sslug.dk/ li
