A Beginner's Guide to Linux




What is Linux?

Linux is an operating system, which is intended to be used as an alternative to other operating systems, such as Windows or Mas OS. Linux acts as an interface between computer/server hardware and the programs which run on it. It can be used for general purpose use on desktops and servers, computer architecture support, embedded systems, security, and support for real-time applications.

Linux in the LTC

Having a working understanding of Linux is very important in the LTC. Students use Linux to maintain their webpage; webpages include at the very least: a biography, research journal, and report. The hostname for the server in the LTC is laser.physics.sunysb.edu and student's username will generally be their first name. We use the Bash interface. We also use SSH, secure shell client, a cryptographic network protocol, which can be to communicate securely and transfer files between two networked computers. Anyone with an active Stony Brook NetID can download SSH for free.

Basic Terms

Directory- a collection of files that are all in on place; can tell you are in directory if command line starts with a d [It is important to note that the parent is unique to a directory meaning you cannot travel "sideways", you can only go up and down]

Command line- where the user issues commands to the program in the form of successive lines of text as a means of interacting with a computer program

Basic Commands

A good 'dictionary' of commands can be found at this website. A basic, although sometimes confusing tutorial about Linux for beginners can be found here. Also if you ever are on another student's website and they have done something, say created a table, that you would like to do, you can ctrl click or right click and choose view source code to see the code they used to create their webpage. Past LTC researcher, Azure Hansen also compiled a list of Linux commands.


In the directory...

  • enter- enters command

  • cd directoryname- changes(opens) directory

  • ls -l- displays all of the files in a directory

  • pico filename- opens/creates file

  • tab- completes filename (if filename is unique)

  • mv filename- moves file

  • cd ..- move up a directory

  • up and down arrows- scroll through past commands

  • cp filename- copy file

  • more- displays output one more screen at a time

  • mkdir directory name- creates new directory

  • ctrl & d- logout


    Once you are in a file...

  • ctrl & o- save without exiting file

  • ctrl & x- save and exit file

  • ctrl & ins- copy

  • shift & ins- paste

  • < a href="websiteurl.html" >words< /a >- links to a website

  • < img src="filename.html">- inserts picture

    1. To change image width and height: < img src="filename.html" width=# height=#>

  • ctrl & a- brings cursor to the beginning of the line

  • ctrl & e- brings cursor to the end of the line

  • ctrl & w word- search a file for a word

  • ctrl & k- cut a line of text

  • ctrl & u- uncut text

  • ctrl & t- spell check [WARNING: will spell check commands as well]


    Formatting

    For all of the commands below, the spaces should be removed

  • < i>word< /i>- italic

  • < b>word< /b>- bold

  • < u>word< /u>- underline

  • < hr>-adds a divider line

  • < font color=color>word< /font color>- changes font color (ex. < font color=red>word< /font color> becomes word)

  • < font size=#>text< /font size>- changes the font size of your text

  • < sup>word or number< /sup>- superscript word or number

  • < sub>word or number< /sub>- subscript word or number

  • < h#>text< /h#>- changes text to different heading style (1 through 3 should be set up for you account)

  • < center, left, or right>text< /center, right, or left>- aligns text to left, right, or center


    How to upload photos

  • ON MACS:

    1. Make sure you are signed out of your account

    2. Enter scp filelocation username@laser.physics.sunysb.edu:public_html into the command line

    3. Sign in to ensure the picture was uploaded correctly and move it to another location if desired

  • ON PCS:

    1. Click the icon at the top of the window on the first toolbar that looks like a file with blue beads wrapped around it

    2. A window will pop up, the left half of the window will represent your computer, the right will represent your Linux account

    3. Find the file you are trying to upload on the left and drag it over to the appropriate location on the right


    Creating bulleted lists

  • < li>< p>- creates new entry in list

  • < ol>

    < li>< p>- creates numbered list; used for bibliographies

    < /ol>


    Special characters

  • & letteracute;- adds acute symbol over the letter (ex. & eacute; becomes é)

  • & greekletter;- writes symbol for greek letter (ex. & mu; becomes μ)