In Linux, the alias command is used to create shortcuts for long commands that have the same functionality as if you were writing the whole command.

The eval command is used to execute specified arguments as a single command in the current command-line processing and return its result.

The WC command is used to count various parameters from the specified file, like the number of lines, word counts, byte counts, character counts, and many more.

In this article, you will learn to count the number of string occurrences in a text file using the grep, wc, and tr commands, including the VIM text editor.

The absolute and relative paths are different ways to navigate through directories in your Linux file system that everyone must know.

Learn how to write and run a shell script using the bash or source command, or run it from the URL and execute it using its path.

The PS is a native command-line utility for UNIX-based systems that monitors the currently running processes in your system.

The export command is used to create environment variables or update variable values in the current shell session by newly forked child processes without starting a new shell session.

The set command is a built-in Linux command that can display or modify the value of shell attributes and positional parameters inside the current shell environment.

The unset command is a built-in Linux command used for flushing the value of variables or functions during program execution.

The “$?” is a built-in variable that your shell uses to store the exit status code of the last executed command in integer format and remains unchanged unless the next command is executed.

The "#! /bin/bash" in Linux, famously known as shebang or hashbang, starts with a pound/hash ("#") sign together with an exclamation ("!") sign.

Like other programming languages, bash provides you with the option to ignore a single line, inline, or a block of lines from execution.

In Bash and also for other implementations of the shell, like zsh and fish, you can use the HereDoc to redirect a multi-line or block of lines from the script as an input to interactive commands.

The shell is nothing more than a program that carries the user typed commands or instructions from the terminal to the kernel.

The kernel is the core of the system that bridges the hardware and software layers and smoothly creates interaction between them to transport data.

The ZSH (or Z shell) can be said to be an extended version of the standard Bash shell interpreter, written by Paul Falstad in 1990 while studying at Princeton University.

The UNIX/Linux CD command is popularly used to move into different directories from the current working directory using the command line.

The read command is a built-in Linux utility that allows shell script writers to take single line input from the keyboard or from the file descriptor and store it in a variable.

Fish is a user-friendly UNIX/Linux shell program that focuses on providing most of the known features by default without requiring any manual configuration.