What is Linux?

Fig. 1 Tux, the official Linux mascot

Linux is a family of free and open-source operating systems based on the kernel created by Linus Torvalds in 1991. A kernel is software that coordinates/interfaces the computer’s hardware and other sofware. An operating system based on Linux is called a distro or distribution.

Every entry on the Top 500 runs Linux. The Palmetto cluster is running a Linux distro called Rocky Linux 8.

This workshop will teach you how to use the Linux command line interface or CLI. For this purpose, we will use a terminal software, such as MobaXTerm or Putty (on Windows machines) or Terminal (on Mac and Linux machines).

The terminal is a wrapper program that provides text-only input and output from the shell. The shell is a program that will allow us to interact directly with the operating system kernel. There are many different shells, but the most common (and the default on Palmetto) is Bash. Bash provides it’s own scripting language which allows us to run commands automatically.

Note

Linux is case-sensitive and typo-sensitive. Commands need to be entered directly as shown; it is important to use the right case (upper or lower), to use spaces when they are needed, and not to use spaces when they are not needed.