Basic Linux usage#

All the VSC clusters run the Linux operating system. Specifically, all clusters currently run some flavor of Red Hat Enterprise Linux.

This means that, when you connect to one of them, you get a command line interface, which looks something like this:

vsc30001@login1:~>

When you see this, we also say you are inside a shell. The shell will accept your commands, and execute them.

Some of the most often used commands include:

ls

Shows you a list of files in the current directory

cd

Change current working directory

rm

Remove file or directory

joe

Text editor

echo

Prints its parameters to the screen

Most commands will accept or even need parameters, which are placed after the command, separated by spaces. A simple example with the echo command:

$ echo This is a test
This is a test

Important here is the $ sign in front of the first line. This should not be typed, but is a convention meaning that “the rest of this line should be typed at your shell prompt”. The lines not starting with the $ sign are usually the feedback or output from the command.

More commands will be used in the rest of this text, and will be explained then if necessary. If not, you can usually get more information about a command, say the item or command ‘ls’, by trying either of the following:

$ ls --help
$ man ls
$ info ls

You can exit the last two manual by using the q key.

Tutorials#

For more exhaustive tutorials about Linux usage, please refer to the following sites: