Linux

1. November 2011 Linux A UMass Amherst M5 workshop Sean Klaiber

2. November 2011 General information

3. November 2011 Why Use Linux? • Save Money • Initial purchase and maintenance • Resume • Linux is used by MANY organizations • More choices • Tons of Linux operating systems

4. November 2011 What is Linux? • Contains the Linux kernel • The kernel is the low-level software that manages hardware, multi-tasks programs, etc. • Linux Operating System • Includes the kernel • Also various utilities to get things done (program to copy files, etc) • Linux Distributions • Software companies will sell extra software • E.g. the desktop environment, games, etc. • Ubuntu is one of many Linux distributions

5. November 2011 Licensing The GNU General Public License Linux is under This means that Linux can be: • Freely copied, changed, and distributed • No distribution restrictions can exist • The source code must be made available to the public

6. November 2011 How Can It Be Free? • Linux developers make money by: • Custom applications for large companies • Tech support • Other jobs that don’t involve Linux Linux (and the Open Source movement as a whole) is an example of how the highest quality results come from those who do work of their own free will

7. November 2011 Ubuntu • Just one of many distributions or “distros” of Linux • Oneiric Ocelot is version 11.10 • Released October 2011 • Developed by Canonical Ltd. • About 500 paid workers and thousands of volunteers • Features: • Unity Desktop Environment • LibreOffice suite • Ubuntu Software Center

8. November 2011 LibreOffice • Fork of OpenOffice • Development began January 2011 • Oracle purchased Sun Microsystems in Jan 2010 • Sun owned OpenOffice and developers didn’t trust that Oracle would continue development • Discontinued development on Sun’s OpenSolaris operating system

9. November 2011 Package Management • Maintains a database of software dependencies & version info • Prevents software redundancies • Automatically organizes software • Ian Murdoch has called it “the single biggest advancement Linux has brought to the industry” • Ubuntu uses the “Ubuntu Software Center” • Can browse, download, and remove software

10. November 2011 Common Problems with Linux • Cannot develop or pre-install proprietary drivers • Doesn’t always work fluidly with all hardware • E.g. Mac touchpads • Cannot run many proprietary software packages • Larger learning curve

11. November 2011 Questions so far?

12. November 2011 Boot time

13. November 2011 Boot Time • Hold ‘c’ while turning on a Mac to boot from the disk drive • Will probably need to install Wireless Card drivers • Top right hand corner • There should be a pop-up announcement • Turn on two-finger scrolling (Macs) • System Preferences • Very top right

14. November 2011 The Command line

15. November 2011 Why Use The Command Line? A relatively simple string of text provides direct and unambiguous access to complicated tools

16. November 2011 POSIX Portable Operating System Interface for UniX • As set of standards that Unix-y (including Linux) operating systems follow to provide portability • Most basic command line tools are POSIX compliant • Means that code written with Ubuntu can be easily run with Mac OSX or Debian or Gentoo or Damn Small Linux… … but not Windows

17. November 2011 OPEN THE TERMINAL Useful Commands cd => change directory ls => list directory contents cp=> copy files/directories cat => concatenate and print files echo => print text mkdir => make directories pwd => prints working directory man => open manual pages less => read file with scrolling find => search for files date => print / modify date

18. November 2011 Task #1 Navigate, Create, Destroy

19. November 2011 Navigation / => root directory ~ => home directory (also ‘/home/<user>/’) .. => directory one level up . => current directory • ‘cd’ allows movement between directories • Syntax: ‘cd PATH_NAME’ • PATH_NAME can be any of the symbols above, a directory name, or some combination for complex movement • ‘pwd’ will print the current directory in case you get lost

20. November 2011 Task #1: Navigate, Create, Destroy • Using the ‘cd’ command, navigate to the Desktop • Hints: The ‘ls’ command will help you find the Desktop • Create a directory in the Desktop using ‘mkdir NAME’ • NAME can be anything you desire • Navigate into this new directory • Create a file and fill it with junk • Use command ‘echo JUNK > FILE_NAME’ • Read the contents with ‘cat FILE_NAME’ • Read the contents with ‘less FILE_NAME’ • Exit ‘less’ by hitting ‘q’ • Remove the file with ‘rm FILE_NAME’

21. November 2011 Standard Files • Standard Outputis printed to the computer screen • ‘>’ will overwrite a file with a functions standard output • ‘>>’ will append the standard output to the end of a file • Standard Input is by default what we type on the keyboard • Use ‘<‘ to take input from a file • Standard Error is an alternative type of output for errors • Use ‘2>’ to overwrite a file with standard error

22. November 2011 Try… $ cd ~ $ ls Desk > FILE_NAME $ cat FILE_NAME $ ls Desk 2> FILE_NAME $ cat FILE_NAME Note that the standard error is not only being written to the FILE_NAME but is being redirected from the terminal to FILE_NAME

23. November 2011 Input Arguments • Try deleting the directory with the ‘rm’ command. Tricky? Command line tools often use input arguments to extend their functionality • Delete the directory with ‘rm –r DIRECTORY_NAME’ • ‘-r’ stands for ‘recursive’ and will delete any file in the directory

24. November 2011 Save Time • Hit the  button at any point to recall the last command • ‘tab’ will fill in the remaining characters for file and directory names if there is only one possible option Use  and tab often

25. November 2011 TASK #2 Process Handling

26. November 2011 What’s a Process? • A process is a program in action • Programs in executable form reside on disk, when run, they are moved into memory and become a process • Linux assigns each process a Process Identification or PID

27. November 2011 Task #2: Process Handling $ gbrainy ‘ctrl-c’ to kill $ gbrainy & $ ps $ baobab & $ps $ kill <PID> $ history (do in new terminal) $ ps $ ps aux | grepgbrainy $ top $ tty

28. November 2011 Nano Text Editor Nano is one of the simplest command line text editors • To create a file, save it, and exit nano: $ nano FILE BWONGG wubwubwubwub<- enter text ctrl-o <- command to save ctrl-x <- command to exit nano

29. November 2011 Piping • Symbol is the vertical line, ‘|’ • Found at ‘shift+backslash’ • Takes standard output left of pipe and uses it as standard input to the function on the right of the pipe

30. November 2011 Piping Hot Example • Create a file with a whole bunch of random words OR random text • Make it so each SET of words or numbers have their own line • While in that directory: $ sort FILE - if using numbers, ‘sort –g’ $ sort FILE | grep ITEM $ sort FILE | grep ITEM | uniq $ sort FILE | grep ITEM | uniq -c

31. November 2011 Task #3 Bach and Forth Between Audio Formats

32. November 2011 APT Package Manager • The Advanced Packaging Tool is what Ubuntu Software Center is built on • ‘apt-get install PACKAGE’ will install and organize software • ‘apt-cache list PACKAGE’ will search for PACKAGE in the local database • ‘apt-get update’ update the local package database

33. November 2011 FFMpeg FFMpeg is a multimedia transcoder • Command line tools to convert sample rates, bit rates, file types, cut, copy, stream, and filter almost any audio, video, or image file • We’ll convert a lossless .flac file to an .mp3 for iTunes $ sudo apt-get install ffmpeg $ cd DIRECTORY_OF_FLAC_FILE $ ffmpeg –iFILE.flac NEW_FILE.mp3 $ man ffmpeg

34. November 2011 Wasn’t that easy?