Linux and Java Basics

What is Linux? Operating system by Linus Torvalds that was a clone of Unix (thus Linux) Free and open source – this is the reason for its success Unix and Linux now both very closely related

Where is Linux? iOS and OSX (Linux like Unix called BSD) Android (Linux) Our server Deep Blue, Watson, CERN’s LHC Military tanks, missile systems, satellites, robots, etc… ~65-80% all internet servers and security devices

Supercomputing?

What’s with all this text only non-sense?

Command Line Interface Every operating system needs to be able to take instructions. The interface for all OSs is done is called the command line. Other names you might see: Shell Command prompt CLI Console / Terminal

But… why are we learning it? The GUI is heavyweight – a robot has limited computing power and using it on running a GUI is a huge waste – Interacting with most of these systems is command line only Understanding this is underneath all the shiny stuff helps you understand computing Will allow you to do advanced non-programming things on your computer

Connecting to Aegis ssh – secure shell connection. How you would work with a robot’s operating system using your computer

Basic Linux Commands - Navigation ls – list. Shows the files in the current or specified directory cd – Change Directory. Switches you to a different directory. rm – ReMove. Removes a file(s) mv – MoVe. Moves a file(s) from one location to another cp – CoPy. Copies a file(s) from one location to another mkdir – MaKe DIRectory. Makes a new directory.

Anatomy of a Command

Tab TAB is your friend! Pressing tab on an incomplete command or argument Finishes it for you (if only 1 possibility) If more than 1 possibility, double tab lists options Saves so much typing and memorization! You should press it… (reasonably) a lot

Your Turn Now, you try!

ls

cd

rm

More Commands! pwd – Present Working Directory. Display the full path of the current directory you are in cat – concatenate. Most used for quickly displaying contents of a file, but can be used to add stuff to ends of files. clear – puts the last line at the top so you have a fresh screen man - get the manual for a specific program, e.g., man ls

Wildcards Wildcard – a character that can be used as a substitute for some set of other characters * - match anything ? – match exactly 1 character of any kind

Wildcards

F! YEA JAVA!

Compiling and Running Java Programs