Linux ufw in Linux ufw (Uncomplicated Firewall) is a Linux utility that runs on top of iptables used to manage netfilter and managing the firewall. We look at ufw in Ubuntu and how to manage the firewall.
Linux vmstat command in Linux We use the vmstat command for system performance monitoring in Linux. It reports statistics about threads, system calls, CPU activity, memory, disks, and more.
Linux firewalld in RHEL firewalld is a Linux utility used to manage firewall rules. In this article we discuss firewall management using firewalld.
Linux iptables in Linux We use iptables to create firewall rules. In this article we learn about iptables and how to manage firewall rules in Linux.
Linux journalctl in Linux In Linux, systemd provides a centrally managed journal where all kernel and userland processes' logs are stored. We use journalctl to interact with journals.
Linux SSH passwordless login in Linux Passwordless login is useful in cases whereby we want to automate server administration tasks. We discuss how to configure ssh passwordless login in Linux.
Linux Accessing a remote server using SSH Secure Shell(ssh) is a cryptographic protocol for networking which encrypts communication between two remote hosts. In this article we learn how to safely access a remote server using ssh.
Linux Managing packages with yum/dnf in RHEL Package management involves managing software on a system. This includes installing, upgrading, downgrading, updating, removing, etc. We discuss package management in Red Hat Enterprise Linux Distros using yum and dnf.
Linux Managing Debian packages with dpkg In Linux software is considered a package and is distributed using remote repositories. As end-users, to access it we use package managers. We discuss the dpkg package manager for Debian-based Linux distros.
Linux Managing Debian packages with apt apt(Advanced Package Tool) is a package management tool. It is used to install, configure, search for, update and remove software in a Debian based Linux system.
Linux Bash until loop Loops are an important aspect in any programming language. In this article we look at the until loop that is used for looping in shell scripts.
Operating System Secure boot Secure boot is a security standard implemented in the advanced UEFI to prevent malware from attacking the computer during boot up when the computer is most vulnerable.
Computer Architecture UEFI and Legacy boot Both UEFI and BIOS are firmware that specify an interface between the computer operating system and the underlying firmware. Legacy boot involves booting the computer using legacy firmware such as BIOS and UEFI boot involves booting a computer using the more advanced UEFI.
Computer Architecture UEFI (Unified Extensible Firmware Interface) UEFI(Unified Extensible Firmware Interface) is the interface between the operating system and the low-level initialization firmware. It initializes hardware components and is responsible for executing the OS stored in a boot device.
Computer Architecture Firmware In this article we discuss firmware - software that is directly programmed into hardware devices such as routers, cameras, network cards etc.
Computer Architecture BIOS (Basic Input Output System) We discuss BIOS - firmware stored in non-volatile memory e.g EPROM, responsible for startup procedures such as POST before passing control to the bootloader which loads the OS.
Linux Types of Boot loaders A boot-loader is responsible for loading the operating system to the Linux kernel and the Linux initial RAM disk. In this article we discuss different boot loaders for the Linux operating system.
Linux GRUB bootloader GRUB is one of the many Linux boot loaders responsible for loading an operating system into memory during startup. In this article we discuss the booting process involving GRUB and how to configure and customize GRUB.
Linux Run levels in Linux Run levels are modes of operation for computer operating systems. We discuss the different run levels in the Linux OS and demonstrate how to change the default run level.
Linux Systemd Components Systemd is a suite of utilities that provide an array of system components for the Linux OS. We look at various components within systemd.
Linux Unit files in Linux A unit file is responsible for specifying how systemd starts and runs. In this article, we discuss unit files, the contents of these files, service and target unit and unit files and how to create and edit unit files.
Linux Systemctl and Systemd in Linux The systemctl command is a systemd utility used to manage services, get information about service unit files and service states and therefore a useful utility to know for managing services on the server while systemd is an array of components for Linux OS.
Compiler Design Data-flow analysis in Compiler Design All optimizations in a compiler depend on data-flow analysis. We discuss three instances of data-flow problems, reaching definitions, live variables and available expressions.
Compiler Design Sethi Ullman algorithm The Sethi-Ullman algorithm is an optimal algorithm used for finding an optimal ordering of a computation tree. We discuss two generalizations that increase its applicability without increasing the cost.
Compiler Design L-Attributed and S-Attributed definitions and grammar We have discussed two classes of definitions that can efficiently be implemented in connection to top-down or bottom-up parsing in compilers and corresponding attribute grammars that result from serious restrictions.