To understand the shell, first look at the following picture: The shell is nothing more than a program that carries the user typed commands or instructions from the terminal and converts them into something that the kernel can understand. If you’re using popular operating systems
If you have been using Linux for a while, then you have definitely spotted this “#! /bin/bash” line at the beginning of an shell script. What is Shebang (#! /bin/bash) in Linux Shell Script The “#! /bin/bash” on Linux, famously known as shebang or hashbang,
While writing shell script, you might get stuck in the situation where you want to redirect a block of lines from your script to interactive commands like sed, cat, ssh, or ftp. The purpose of this redirection might vary from situation to situation. For example,
Like other programming languages, bash provides you with the option to ignore a single line, inline, or a block of lines from execution. The comments always received the least attention due to their simplicity but played a very important role while being used in a
The “$?” is a built-in variable that your shell uses to store the exit status code of the last executed command in integer format and remains unchanged unless the next command is executed. Using this exit status code, you can debug the problem that occurred
The unset command is a built-in Linux command used for flushing the value of variables or functions during program execution. Tutorial Details Description Unset Difficulty Level Low Root or Sudo Privileges No OS Compatibility Ubuntu, Manjaro, Fedora, etc. Prerequisites unset Internet Required No Syntax of
The set command is a built-in Linux command that can display or modify the value of shell attributes and positional parameters inside the current shell environment. This modification can help to debug your script by finding undefined variables, errors, job control, printing commands as they
Whenever you start a new shell session (by opening a terminal), a set of environment variables is loaded from the shell configuration file into your current shell session. These environment variables determine different customizations in your shell, like the default editor using “$EDITOR“, or setting
The PS, a.k.a. “process status”, is a native command-line utility for UNIX-based systems to monitor the currently running processes in your system. It reads the information from the virtual files in the /proc filesystem and gives the running processes information like memory consumption, CPU usage,
How do I write and run a shell script on Linux? Is there a way to run a shell script without executable permission, or can we run a shell script directly from a URL? Don’t worry; you are about to learn all those things in
The bash (Bourne-Again SHell) is a sh-compatible command-line interpreter that reads from standard input or from a file and gives you the resulting output. We have already written an article about bash and its differences from the standard POSIX shell. Today, you will learn how
Before understanding what is Bash shell, you must be familiar with the concepts of a command-line interpreter and Linux Shell (or sh). What is a Command-Line Interpreter? The term “command-line interpreter” refers to a program or text-based interface that sits between the user and the
