Linux Overview. Local facilities. Linux commands. The vi (gvim) editor

Transcription

1 Linux Overview Local facilities Linux commands The vi (gvim) editor

2 MobiLan This system consists of a number of laptop computers (Windows) connected to a wireless Local Area Network. You need to be careful not to turn the wireless sensors off or you won t be able to connect to the network. The computer needs to stay in the same room as the cart the wireless is fairly local Be sure to shut the computer down before bringing the computer back to the cart.

3 Secure Shell We will be using the SSH program to connect to onyx Start the program Start a new session Type your user name and password Now you can practice using the command-line interface to Linux as I talk about it

4 Working with Linux There are a number of links to handouts about Linux and vi at Local Linux Guide basic Unix commands getting started with vi

5 command line interface Using the console can be faster than navigating graphical windows and menus. When you access the server via the Internet, the console mode is much faster to use than the graphical mode. If you are coming in from Windows than the console mode is all you have. So it makes sense to learn your way around the console mode. You can start up a console window by clicking on the icon for the Terminal program (the monitor icon) on the panel. Once you have opened a console, use it to learn a few basic commands. navigating directories (also known as folders) creating directories moving across directories copying files deleting files

6 Basic Linux commands Command cd Effect takes you to your home directory cd dir1 takes you to directory dir 1 cd.. ls ls -l mkdir skills pwd cp file1 skills mv file2 junk mv xyz skills rm junk go up one level in the directory tree list all files in the current directory shows detailed listing (includes file sizes, date created etc.) makes a new directory called skills print the name of the working directory copy file named file1 to the directory skills rename file2 to junk move file xyz to the directory skills remove file junk

7 Changing your password You can use the command passwd to change your password to something that is easier to remember. But don t make it too easy or it will not be secure. You should use a mixture of letters and digits up to 8 characters. When you type passwd, you will be asked to enter your current password once to log into the main onyx server and again for the passwd command. Then you will be asked to enter the new one twice.

8 You have several choices of clients on onyx. When you are in the lab, you have a graphical program called evolution available to use. Once it has been set up, it should be reasonably self-explanatory. If you are logging in remotely, there are several text-based programs: mutt, pine, elm, mail (in decreasing order of user-friendliness in my opinion)

9 Forwarding mail If you don t want to deal with mail on onyx, you can forward everything to another account. Go to your home directory (Type cd) Create a text file named.forward which should contain the address you want to forward to and nothing else. You can use vi.forward i user@isp.net ESC ZZ If you want to keep a copy of your mail on onyx, you can replace the 3rd line with \onyxuser, user@isp.net Grades for programming assignments get sent to onyx so you need to do something about either using mail on onyx or forwarding your .

10 Redirection We will be writing programs that read from the keyboard and write to the console. You will probably find yourself typing in the same sequence of text over and over as you debug the programs. You can save yourself some typing by using input redirection. Basically, this allows you to replace the keyboard with a text file for a single run of the program. Put the text that you would have typed into the program in a file (datafile below) and then type java MyProg < datafile Similarly, you can redirect the console output to a file by typing java MyProg > outfile You can do both at once as well java MyProg < datafile > outfile

11 Logging out Make sure you are completely logged out before you leave the lab. The logout option is on the start menu on the main panel at the bottom. Be sure the login screen is visible before you leave the lab. There are gremlins in the lab who have been known to play tricks on people who forget to log out before leaving the lab. Typing exit will close an xterm window but it does not log you out.

12 Remote Sessions via ssh Download a free Secure Shell Client for your home computer from PC: Mac: Once you install this package, you have two programs: 1. the ssh terminal that lets you connect to onyx remotely 2. a secure copy (scp) client that lets you copy files between onyx and your computer. The ssh programs are secure since they encrypt your password and data before sending over the Internet.

13 Using the workstations in the lab The computer labs are ET 213 and ET 214. You can enter through ET 239 when it is open You can use the combination for the keypad lock (96350) anytime you can get into the building

14 Logging in Choose a computer and make sure everything is turned on. Move the mouse if necessary so that you can see the login screen. Enter your user name and password in the appropriate dialog boxes. Now you should see the KDE desktop which provides you with a graphical interface (GUI) to the operating system

15 The KDE Desktop The KDE desktop looks similar to the Windows desktop. Icons on the desktop can be double clicked to open/start them. The taskbar at the bottom of the screen (usually) has a number of useful things. The Red Hat icon is a menu that lets you start programs and logout. The icon that looks like a terminal opens up a Terminal window. Here you can type commands. More on this later. The control center lets you modify the looks of your desktop. The life-saver opens up a help window. The house icon will give you a window showing the files and directories in your home directory. Use the Lock/Logout applet (either in the taskbar or in the red-hat menu) to log out of your session.