The servers of CSC use Linux operating systems. While the users local computer is normally used mainly through a graphical user interface, the remote usage of the servers of CSC is based on working on command line: instead of using mouse and command menus, the user types commands to a screen called command shell. Even though more and more tools provided by CSC can be used through graphical interfaces, using the basic linux commands is in many cases them most efficient way.

This chapter provides introduction to the usage of the Linux environment of CSC. The application server, hippu.csc.fi, is used in the examples but the same commands can be used in the other servers of CSC too. If you are using Linux or Mac OSX machine, you can use most of the commands in your local machine too. Once you are familiar with the basic linux commands, you should also study the chapters 3 Linux tools for working with data and 4 Managing files in linux environment  that go deeper to the file management commands of linux systems.

This guide is accurate for both bash and tcsh shells. If you are using some other linux command shell like sh or ksh, all the details may not apply

The default shell for new users in the CSC computing environment is bash. Before 1st June 2012 the default was tcsh. Users can change their shell using the chsh command. CSC fully supports both bash and tcsh shells. Customers using other shells are also supported, but may be asked to reproduce any issues in bash or tcsh.

Differences between bash and tcsh shells are described sections 2.3 and 2.4.

2.1 Using linux in command line
   2.1.1 Files and directories in linux
   2.1.2 Structure of linux commands
   2.1.3. Basic command for using directories
   2.1.4. Basic commands for files
   2.1.5. Special Characters
     2.1.5.1 Wild card characters
     2.1.5.2 Redirecting standard input and output

2.2 Text and image processing
   2.2.1 Nano
   2.2.2 Emacs
   2.2.3 Image and PostScript viewers

2.3 Working with tcsh shell
   2.3.1 Command line editor
   2.3.2 Automatic Tab completion
   2.3.3. Stopping programs and running programs in background

2.4 Working with tcsh shell
   2.4.1 Command line editor
   2.4.2 Automatic Tab completion
   2.4.3. Stopping programs and running programs in background

2.5 Changing shell