Linux Guides

Introduction to Linux

Linux is a UNIX-like operating system, composed of three fundamental components:

  • Kernel : Manages hardware resources and handles process execution, memory, device drivers, and system calls.

  • Shell : A command-line interface that interprets user input and communicates with the kernel.

  • System Programs : Provide essential functionalities such as user environments, file and process management, networking tools, and scheduling services.

In Linux, everything is treated as either a file or a process:

  • A file is any collection of data, including directories, device nodes, and configuration files.

  • A process is an executing instance of a program.

Directories themselves are implemented as a special type of file that contains mappings of filenames to index node references.


Linux FAQs

How can I check my shell?

$ echo $SHELL or $ echo $0

How can I view my environment variables?

$ env or $ env | sort

How can I check command/software availability and location?

$ which executable, for example $ which vim

How can I get help with commands/software?

Use the Linux manual pages: $ man executable, for example $ man vim