In this article, you will learn what the difference is between variables and parameters, what special parameters are, and a list of predefined special parameters in Bash. What are “Special Parameters” in Bash? Before you can understand what special parameters are, you must first understand
If you are a sysadmin, then wall command can be your next favorite Linux tool, thinking why? With the help of this tool, you can broadcast messages to all logged-in users on your system, either locally or via SSH. This tool comes in handy, especially
The ps and top commands are the most popular and commonly used command-line programs to view the currently running processes on your Linux system. The pstree is also similar to them, except that it outputs the running process in the form of a tree; if
This article will show you three methods for determining whether your Linux system is using systemd or another init system. If you are unfamiliar with this term, check the following section; otherwise, skip to the next section. What are Init and SystemD in Linux? The
This article will teach you what systemd is and why it replaced SysVinit; what systemd unit files are; how to list all and specific unit files; and how to view the content of a unit configuration file. Why SystemD? To understand Systemd, you must first
In this article, you will learn about the short description of the init process, the runlevels of init, and the init command in a Linux system. What is Init Process? In layman’s terms, when you press the power button, your system will first look for
Proc file system (short for “procfs”, referring to “/proc” dir) is a virtual file system (not a real file system) that is mounted on system boot to store information related to running processes. The proc file system stores useful information about the running process and
In this article, you will learn everything about file descriptors, like their uses in Linux, what a file descriptor table is, how to view the file descriptors under a specific process, and how to change the limit of a file descriptor in Linux. What are
In this article, you will learn what an inode is, how to check an inode and its size in Linux, and their roles in soft/hard links and system updates. What is Inode in Linux? In your Linux filesystem, an inode (or index node) is a
When you interactively login to your system, you usually interact with your main shell from the terminal to execute commands; however, from your main shell (or parent shell), you can spawn a subshell (or child shell). Confused? I knew this would be more difficult, especially
The UNIX/Linux shell is a command-line program that creates a bridge between the terminal emulator and kernel to allow users to enter commands, execute programs, and perform various other tasks by typing commands at the command prompt. Once the shell has finished executing the user
The “login shell” is a term used to define which shell (like Sh, Bash, or Zsh) will be used to load the environment variables and shell configuration files when you log into an interactive session. 💡 Once you log into your system using a pre-defined
