Introduction to Linux

Delve into all the basic concepts of Linux Shell.

Linux is a free open-source operating system that works just like Windows and Mac OS X. It is a Unix clone, multi-tasking and a multi-user operating system that was developed by Linus Torvalds with the collaboration of the developers around the world.

Linux - A Kernel, not an Operating System

Strictly speaking, Linux is a kernel, not an entire operating system. A kernel provides access to computer hardware and a controlled access to system resources such as:

  • Security and firewall
  • GNU libraries and utilities
  • Other management and installation scripts
  • Logged in users
  • Running and loading programs to memory
  • Networking systems
  • Files and data
  • Process management
  • Device management
  • I/O management

Shell Classification

  • Command line shell
  • Graphical shell

Introduction to Linux Shell

A shell is an environment provided for the user to interact with the machine.

Shell is not a part of Linux kernel, but it uses the kernel to execute programs, create files etc. Several command line shells are available for Linux including:

  • BASH ( Bourne-Again SHell ) - It’s the default open source shell on many Linux distributions today
  • CSH (C SHell) - The C shell’s syntax and usage are very similar to the C programming language
  • KSH (Korn SHell) - It is a high-level interactive command language
  • TCSH - It is an enhanced but completely compatible version of the Berkeley UNIX C shell (CSH)
  • ZSH - It is an interactive shell that incorporates features of other Linux shells including some unique ones too
  • Fish (Friendly Interactive Shell) - It is a smart and user-friendly interactive shell along with some other features