====== Linux Basics ======

===== Files, Directories and Paths =====
  * a //file// is a collection of data with a name (a //filename// to be precise).  Although it may be stored in separate chunks in different location on the hardware, programs will generally work with a file as a single continuous collection of data.

  * a //directory// is construct for grouping and organizing //files//.  In UNIX and Linux, //directories// can contain, //files//, other //directories//, //links// and //devices//.  You may be use to calling directories //folders// or //namespaces//. 

  * a //path// is a way of naming the location of a file, directory, link or device.  //Paths// can be //relative// or //absolute// and are often used as the prefix to a filename. For example, if I want to list the contents of a directory that is in my home directory called ''cheese'', I can type: <code>ls ~/cheese/</code> 

  * a //link// is a filesystem pointer.  You may be use to calling a //link// an //alias// or a //shortcut//  


===== Shell commands =====

  * **//ls//**: lists the files in your current working directory for that shell.
    * more ways: **//ls -a, ls -l, ls -la//**
  * **//cd directory//** : changes the current working directory to directory where directory may be a fully qualified path. A ~ indicates your home directory. ~bob indicates the home directory of bob.
  * **//rm filename//** : removes the file filename where filesname may be a fully qualified path
  * **//cp source destination//** : copies the file source to the file destination where source and destination may be fully qualified paths.
  * **//mv source destination//** : the same as //cp//, but it moves the source file instead of copying it. mv can also be used to rename a file with mv oldname newmane
  * **//chmod #### file or directory//** : changes the file or directory permissions for letter yourself and other people access your files. see //man chmod// for more info.
===== Basic Utilities =====

  * Printing: the **lpr** command is the basic printing command. in your shell, type: "lpr filename " to print the file filename to the printer specified in printername or "lpq" to get a list of jobs sent to the printer.
  * File compression: "gzip filename" will compress the file filename and give it the .gz name extension. "gzip -d filename.gz" or "gunzip filename.gz" will decompress the file and remove the .gz extension.