Linux guide:

 Short command Summary:


Allows system to identify you as a user and apply the appropriate ownership to files you create and modify. Each user has his or her own environment and can run Programs simultaneously with other users.


Closes open files and ends processes that are "owned" by the current user. Always log out of the system when finished using it.

 Command Line

The UNIX command line allows you to create complex functions by stringing together a variety of built-in commands. What requires specialized software on other systems can usually be accomplished using built-in UNIX utilities.


See below for a summary of what a shell is.

There are many shells available for UNIX. Which one you will use depends on your needs. Are you a:

  • Programmer
  • Power user
  • Everyday user
How you see yourself will guide your choice of Shell

Using the





Using Shells

"When you are typing commands into Linux, you are typing them into what is known as a shell. For all the old DOS users out there, a shell is equivalent to COMMAND.COM. If you remember the days of DOS, you probably also remember different DOS shells that added capabilities to your computer. UNIX has a wide variety of shells that you can use, each offering a different set of capabilities."

"Shells also provide a scripting language, much like a DOS batch file, but far more capable. Programs written using a shell are called shell scripts."

Available Shells

To use a shell: (note: these will probably not work in the KDE desktop.)


Commands are CASE SENSITIVE.

Be aware of the PATH environmental variable.

Only those commands that are in the directories specified in the PATH variable can be run just by typing the command name.

To run a program in a non-environmental-path directory, specify the path to it

To run a program in the current (but non-environmental-path) directory,

  • Type ./program-name
  • ./ always refers to the current directory.


To short out a program (from the command prompt)

  • Ctrl+d -tells the computer you are finished sending input to a command. Useful if you’ve accidentally started a program and can’t get out
  • Ctrl+c -the UNIX break character. Kills any program that is running and returns you to the command prompt.
  • Ctrl+z -suspends current process you were running, returns you to a command prompt. Logging out kills the suspended command.