Lab - Intro to UNIX / Linux

1. openSUSE 11 distribution of Linux (see System Monitor)

2. This uses GNOME GUI - many different GUIs - what you see here will not be the same on other Linux/UNIX
   • bottom LHS - Start button
   • bottom RHS - show desktop (or Ctrl-Alt-D) (actually toggle raise/lower all windows)
   • Alt-Tab - switch between applications
   • Keyboard shortcuts on different OSes and GUIs

3. multiple desktops
   • If you go to corner, it flips to other desktop.
   • To turn this off: Control Center - Desktop Effects - Edges

4. Web browser - Firefox (also on Win)
5. Email client - Thunderbird (also on Win)
6. To view Microsoft Office files see OpenOffice

7. Explore:
   • Computer - Control Center
   • Computer - More Applications
   • Calculator
   • Take Screenshot (PrintScreen pops up an application to save as PNG)

8. File Browser
   • dirs = directories (folders)
   • View - Show Hidden Files

9. hidden files (begin with .)
   • .profile - run at login
   • .bashrc - run for every shell instance (e.g. shell script)

10. Terminal - bash command line - very powerful - similar to all other Linux/UNIX
    • Unix shell
    • List of Unix utilities
    • Shell script
    • clear - clear screen
    • Ctrl-C - interrupt program

11. command history
    • up/down arrows
    • history
    • !n - repeat command n
    • !string - repeat last command that began with string
    • !c - repeat last command that began with character c
    • !! - last command

12. see files
    • ls
    • ls -a
    • ls -l
    • ls -al
    • echo * (all non-hidden files)
    • echo .* (all hidden files)
    • echo .* * (all files)
    • ls -l * (if dir, will display contents)
    • ls -ld * (if dir, display name not contents)
    • ls -l .* (don't need -a if going to actually name the hidden files)
    • ls -ld .*
    • . (current dir)
    • .. (parent dir)

13. show environment variables
    • set
    • env
    • env | sort
    • echo HOME - the string "HOME"
    • echo $HOME - the global (environment) variable HOME
    • PATH = list of dirs searched for command when you type a command, separated by colons (:)

14. multi-user file system
    • HOME = something like:

        /users/mse1/username  
        /users/gdf1/username 
      

    • For historical reasons, my test account is here:
      /users/gdf1/mhtest09
    • cd to go home
    • cd .. to go up one level:

        /users/mse1
        /users/gdf1
      

    • directory permissions
    • rwx-----x
      • rwx - "user" can do read-write-execute
      • --- - "group" cannot access at all
      • --x - "others" can access files if you know the file name (cannot list contents with ls) - http server can serve up file if it is named

15. simple text editor - gedit
    • right-click on file - open with gedit
    • $ gedit file &
    • launch any windowed app from command-line - use "&" to detach app or else command-line hangs until app exits
    • saves backup files: file~
    • has syntax highlighting
    • touch file - make new file
    • or just run gedit with new filename - if doesn't exist, gedit creates it

16. other editors
    • Emacs