Tutorial: Introduction to CS1620 (This file found at http://www.cs.uleth.ca/~bomhof/cs1620A/tutorials/tutorial1.html)

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1. IMPORTANT !!!   NEVER, EVER, For Any Reason Turn off the Power to a Workstation!
   Why?  For 2 main reasons:
   1. These are Multi-User systems, which means that any number of people could be logged in and using the system.  So shutting down the machine could cause major grief to other people.
   2. Unless shutdown with the proper procedure, the File System, or what is on the hard drive could become corrupted and could even prevent the machine from rebooting properly.

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2. Lab C513 - Generally open 24 hours except on weekends. This lab has Dell Precision 370's running 3GHz Intel P4 processors. They have 1GB of RAM and 80GB Hard Drives. They are installed with Red Hat Fedora (Linux) operating system. All the machines will have a name ending in "er".
   The HP LaserJet 4300 PCL 6 printer is named "cs4".
   
   
3. Lab D519 - Generally open 24 hours except on weekends. This lab has Dell Precision 370's running 3GHz Intel P4 processors. The have 1GB of RAM and 80GB Hard Drives. They are installed with Red Hat Fedora (Linux) operating system. All the machines will have a name ending in "er".
   The HP4500 printer is named "cs1".
   
   

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4. Your Linux course account gives you:
• ownership of a home directory (e.g. /home/doej1620)
• 300MB disk space. You do not have access to the hard drive.
• For printing you will need to C513 and obtain a prepaid printing card. You can find instructions on the red "gum-ball" looking dispenser machinge in room C513.
• Access to the library directory "/home/lib1620" (it also can be referred to as $L).
• Access to the internet using Mozilla Firefox (no Microsoft products on these machines).
• Your Account is for course work only!

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5. Passwords:
• MUST be changed after your first login.
• MUST be at least 6 characters long. Only first eight are significant.
• MUST have at least two alphabetic characters.
• MUST have at least one non-alpha (numbers, punctuation).

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• Changing your password: First decide on your new password. Linux is very fussy about passwords as any dictionary word will not work. Neither will words in reverse. A suggestion for a password might be: The year you were born followed by the first three letters of the street you lived on followed by the address. Eg: 87Agn582. Anything that is not a word.
• REMEMBER: UNIX is case-sensitive (it matters whether it is upper or lower case) and this applies to passwords. REMEMBER: If your password is longer than eight characters your non-alpha must be within the first eight.
• Before you type in your new password write it down. Once you change it you must remember it. You will need to talk to Trent the system administrator (C512) if you forget it.
• Type "passwd" - this will ask for your old password and then your new one. You will need to type it in again to confirm it.
• The next time you login be sure to use your new password.

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6. Logging in from Home:
• If you have a broad-band connection (Shaw or Telus) just telnet to "linux[0-3].cs.uleth.ca".
• Remote logins:
• You can easily do you work from home by connecting to your doej1620 account from home. You need to do a remote login. The best way (and most secure) is to use a program called SSH which available for free. SSH is a program that allows you to remote login and a file transfer program in one.
• Simply download the SSH Shell Client program. You will be asked what to do and choose save it to disk. Double click the downloaded file to install it. Once you have it installed double click on the SSH client program to run it. To make the connection, on the Quick Connect option type linux[0-3].cs.uleth.ca as the host name followed by doej1620 as the user name. Then your password is required and voila, you have a terminal window from where you can do your work. Be aware that you do not have mouse control when editing programs on the shell window like you do in the labs.
• From within the SSH client program you can also call up the file transfer program if you need to move a file from your desktop to your doej1620 account. .

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7. An analogy of Software between Dos/Windows and UNIX

 

Windows XP	Gnome (Red Hat version)	GUI - Graphical User Interface / Windows Manager
MS-DOS	Solaris/Linux	O/S - Operating System - Responsible for Memory management, file management, etc. and standard utilities
MS-DOS Prompt	bash shell	interface that interprets the commands for the o/s
borland c++	gnu c++	compiler for c++ programs
notepad, wordpad	gedit, emacs, vi	editors for creating and modifying text files
Internet Explorer	Firefox	web browser




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8. UNIX File Structure:
• Tree Structure - root is "/"  (not to be confused with DOS's "\")
• Directory Structure Example

• Commands like "ls", "more", and "cd" are executable files, in the tree structure.
• Files can also be simple text, source code for programs, html files, data files, or directories.
• File extensions (the part after the ".") are often used (but not required) in filenames to indicate what kind of file they are.  e.g. HelloWorld.cc indicates that this is a C++ source code file.
• Filenames that start with "." e.g. ".bash_profile" and ".bashrc" are start-up or configuration files, so do not modify or delete them.
• When you are logged in, you are always "in" some particular directory, initially your home directory. You can get the name of the directory by typing the "pwd" (Present Working Directory) command.
• You can  "cd" (change directory) to or "ls" (list) files in another directory provided that the permissions on the directory or files in question, have had permissions set to allow you to.
• These and other commands will be further explained in subsequent tutorials and labs.

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9. Directory Abbreviations:
• .  (single period or dot) refers to the current directory.
• .. (double period or dot dot) refers to the parent directory (the one "above" the current directory).
• ~ (tilde) refers to your home directory.
• $L refers to the library directory (/home/lib162[0123] depending on which section you are in)  Remember that it must be a Capital L.

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10. Printers:
• cs4: In C513 (Linux lab, C section)
• cs1: In D519 (Linux lab, D section)
• Note: The only type of files you can print from the command line are "text" and "postscript" files
  eg. lp myfile.txt or lp -d cs1 myfile.txt
  The first prints a text file to printer cs4 in C513, the second prints the file to cs1 in D519. Any other files, especially if you have a .pdf file will need an application (OpenOffice, Acrobat reader [/usr/local/bin/arcoread], image viewer, etc...) to print from.
• ***WARNING*** Attempting to print non-text, non-ps files from the command line, usually results in a HUGE waste of paper (empties the entire paper tray, printing one line of garbage to each page). So, for the sake of our trees please think twice before you hit the Enter key?

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11. Pathnames:
• Simple - a filename or directory name in the current working directory
e.g. ls changing.password
ls -> UNIX command to show a directory listing.
• Absolute - a list of directories starting from '/' (root) to the desired directory or file with each name separated by '/'.
e.g. ls /home/lib1620/samples -> lists the files in the specified directory
Note: ls $L/samples is equivalent to the above.
• Relative - a list of directories below the current directory, separated by /'s ending with the desired file or directory. Note that relative pathnames NEVER start with / (root).
e.g.
cd  /home/lib1620 -> absolute (b/c it has '/' at front)
ls  my* -> simple (lists all files that start with my in current directory)
more  samples/HelloWorld.cc -> relative