Administration

>> Checking vi Version Installed on a Linux Machine

>> How to Display Wireless/WiFi Information in Real-time in Linux

>> Getting a Unique Machine Identifier

>> How to Properly Manage Multiple Python Versions

>> How to Write iptables Logs to a Separate File

>> Meaning of Systemd multi-user.target

>> Moving Files to Directories Based on the Extension

>> Set and Determine the Baud Rate of a Serial Port in Linux

>> How to Install LaTeX on Linux

>> How to Combine Two Logical Volumes on a Single Physical Volume With LVM

>> How to Login as User “jenkins” After Installing Jenkins

>> How to Operate as Root in GUI

>> How to Expire a Password for Initial Account Creation

>> Start Systemd Service After Specific Service

>> How to Read Log Files Between Two Dates

>> Start a systemd Service Conditionally

>> How to Leave a Message for Another Local User in Linux

>> IP Address Geolocation Lookups on Linux With GeoLite2

>> Viewing Apache Enabled Modules in Linux

>> Placing Files in RAM in Linux

>> Cleartext Passwords in the Shell and How to Handle Special Characters

>> Using Active Directory to Authenticate Linux Users

>> Good Place to Install Custom Bash Scripts in Linux

>> Checking Which Processes Are Using Semaphores

>> Encrypted Remote Backups via rsync

>> What Do ALSA Devices Like hw0,0 Mean?

>> System Calls and Library Calls in Linux

>> Setting the Default python to python3

>> Encrypting and Decrypting Directories on Linux With gocryptfs

>> How to Filter strace’s Output Using grep

>> What Happens to Scheduled Crontab Jobs When the Computer Is Shutdown

>> Dropping Page Cache in Linux

>> Increasing Scrollback Buffer of a Screen Session

>> How to Do a Complete Clean Reinstall of MySQL on Linux

>> Pass the Password to su/sudo/SSH Without Overriding the TTY

>> ssh-agent Forwarding and sudo Into Another User

>> What Does mdev Mean in ping Statistics?

>> How to Check Whether Terminal Can Print Colors

>> How to Remove Default Gateways via ip

>> Extracting the Contents of an RPM Package Without Installation

>> Checking Whether the Display Server Is Xorg or Wayland

>> How to Output a Variable in Nginx Log for Debugging

>> How to Navigate Man Pages Efficiently

>> Clear the Cache of Nginx

>> Why Is chmod -R 777 / Destructive

>> Splitting a Large Nginx Configuration File

>> Path of Bash Script From Symbolic Link

>> Custom Welcome Message for SSH

>> How to Change the Default vsftpd FTP Server Path

>> Difference Between apt and apt-get

>> How to Install and Set Up Headless Linux

>> Adding Other Operating Systems to the GRUB Bootloader

>> Locales and How to Find Character Encoding of Linux Terminal

>> Extend The Session Time for sudo

>> Nginx Flags: Difference Between break and last

>> How to Automount USB Devices in Linux

>> Difference Between apt-get update and apt-get upgrade

>> How to Reinstall Apt on Ubuntu/Debian

>> The Interactive and TTY Options in docker run

>> How to Manage and Keep Environment Variables When Using sudo

>> What Is an ELF File?

>> How to Create a Linux Live USB With Persistence Using Easy2boot

>> How to Solve the “sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set” Error

>> How to Automatically Suspend and Wake a Linux Machine

>> Managing the Way the File Is Cached in RAM

>> How to Control Variable Access in the sudo Environment?

>> Prevent Specific Package Update in Linux

>> /etc/shadow and Creating yescrypt, MD5, SHA-256, and SHA-512 Password Hashes

>> Reordering UFW Firewall Rules

>> How to Delete Files With Names That Contain Non-printable Characters

>> Swap Partition vs Swap File

>> What Is the /dev/mem File?

>> Ways to Stop and Restart a Linux system or the Difference Between halt, poweroff, shutdown -H, and shutdown -P

>> Resolving Unmet Dependencies on Linux

>> Using systemctl to List All Failed Units

>> Use Bash With Alpine Based Docker Image

>> Temporarily or Permanently Disable Every Job Listed in a Crontab

>> How to Use which on an Aliased Command

>> How to Run a Cron Job Periodically Between a Time Range

>> How to Backup Cron Files

>> Manual Network Configuration in Linux and How to Set a Static IP Address

>> Manually Add a User Without Tools Like useradd and adduser

>> How to Allow Only SSH Access Using iptables

>> Using SSH Name Resolution to Associate Name with IP

>> Adjusting Screen Resolution in Linux

>> How to Use the Batch Mode of rsync

>> Automate Commands Upon SSH Connection

>> Docker Image Storage on the Host Machine

>> How to Setup a Base Package Repository in RHEL

>> Using Colors With the watch Command

>> SSH Key Types and Formats or How to Convert PuTTY .ppk to OpenSSH Keys Under Linux

>> How to Uninstall Nginx Completely

>> SSH Key Comments and Adding a Comment to an Existing Key

>> Check How Long the Linux System Has Been Running

>> Send a Message to the Systemd Journal From the Command Line

>> Output a List of Changed Files From rsync

>> Docker Compose: Wait for Container X Before Starting Y

>> Properly Remove an RPM Package

>> How to Fix Docker’s No Space Left on Device Error

>> Disable Hyperthreading From a Running Linux System

>> Using sar to Show Current and Past System’s Statistics

>> Running a Docker Image as a Container

>> Difference Between VBoxVGA, VMSVGA, VBoxSVGA in VirtualBox

>> Connecting to a Windows Machine From Linux With Putty

>> Check if IP Multicast Is Enabled

>> How to Clear Logs in Linux

>> Creating a Non-login User on Linux

>> How to Disable IPv6 Globally and on a Specific Interface

>> Check Whether a MySQL Database Exists Using Shell

>> Guide to the Boot Process of a Linux System

>> Add a Volume to an Existing Docker Container

>> Obtain Kernel Config from Currently Running Linux System

>> Passing Multiple Parameters to a systemd Service

>> Creating and Removing systemd Services

>> Get Username by User ID in Linux

>> How to Verify the Speed of My NIC?

>> Add a User in Alpine Docker Image

>> Script to Automatically Test if a Website Is Available

>> List All Superusers in Linux

>> Linux Error “No passwd entry for user”

>> Create a Virtual Machine in VirtualBox From a Physical Installation of Linux

>> How to Set Default Entry for the Grub Menu

>> Reset a Lost User’s Password

>> Check If a User Exists in Linux

>> How to Check Cron Logs in Linux

>> Using Environment Variables in Nginx Config File

>> Difference Between sites-available, sites-enabled, and conf.d Directories

>> Run a Shell Script Without Using “sh” or “bash” Commands

>> The update-alternatives Command in Linux

>> Force Logout a User in Linux

>> The /proc/meminfo File in Linux

>> Make Apache Web Server Listen on Two Different Ports

>> How to Use UFW (Uncomplicated Firewall)

>> How to Install and Use Popular Linux Bootloaders

>> Running MongoDB as a Docker Container

>> Monitor Device Events in Linux

>> How To Detect Disk’s I/O Bottlenecks

>> How to Change the Timezone on Linux

>> Optimize Battery Life in Linux

>> Linux GUI Tools for Git Similar to Sourcetree

>> Purpose of Swap Files in Vim

>> Allow Users in fstab File to Read and Write to a Partition

>> Restart a Stopped Docker Container

>> How to Clean Up a Linux System

>> Expand the LVM Space on a Server Accessible Only via SSH

>> How to Resize and Move Partitions in Linux

>> Linux error ‘sudo: no tty present and no askpass program specified’

>> Checking a User’s Sudo Access

>> Linux Memory Overcommitment and the OOM Killer

>> Unlocking a Linux User Account After Too Many Failed Attempts

>> Setup Default Desktop Environment on Start Up

>> Wipe Free Space in Linux

>> What Is X11?

>> Monitor Internet Bandwidth Usage on Linux

>> How to Check if a Shared Library Is Installed

>> How to Delete a User in Linux When the System Says Its Currently Used in a Process

>> How to Add Public Key to known_hosts File

>> Boot Linux in Command Line Mode Instead of GUI

>> How to View CPU Speed on Linux

>> Limits on the Number of Linux File Descriptors

>> Customizing Bash Prompt

>> Difference Between a Terminal, Shell, TTY, and Console

>> Docker Error Bind: Address Already in Use

>> Installing and Managing Multiple Node.js Versions in Linux

>> Changing the Primary Monitor in X and Wayland

>> How to Ignore File Properties When Using rsync

>> Add a User to Multiple Linux Groups

>> Running Docker Without sudo

>> Terminal Shortcuts and How to Unfreeze the Terminal After Pressing Ctrl-S

>> Run Part of a Shell Script as a Different User With Runuser

>> Primary and Secondary Groups in Linux

>> Checking the Health of a Storage Device in Linux

>> Figuring Out Which Files in /dev are Block USB Devices

>> Introduction to Flatpak in Linux

>> List All Users in a Linux Group

>> Find Out Linux Distro Through the Command Line

>> Allowed Characters in Linux Environment Variable Names

>> List Installed Packages in Linux

>> Creating and Restoring a Linux System Image

>> Get the Current User in Linux

>> Where Are sudo Incidents Reported?

>> Find Out System Hardware Info From the Linux Command Line

>> How to Completely Remove a Package in Linux

>> What Is /dev/sda in Linux?

>> Monitoring Linux File Access With auditd

>> Guide to Virtual Disk Images

>> Syncing Time With Network on Linux

>> Get Current System Time Zone in Linux

>> Monitor Resource Usage of a Single Process

>> Restrict Size of the Buffer Cache in Linux

>> How to Set or Change System Hostname in Linux

>> Benchmarking Linux Systems

>> The Difference Between Systemctl and Service Command in Linux

>> Checking the Battery’s Status via the Terminal

>> Log the Memory Consumption on Linux

>> How to Compile 32-bit Binary on 64-bit Linux System

>> How to Extract IPv4 Addresses from Files in Linux

>> List All Available Commands and Aliases in Linux

>> Find Out CPU Temperature from the Command-Line

>> Bash Command to Check if Oracle or OpenJDK is Installed

>> How to Obtain Basic Information About System and Disk Partitions?

>> Linux Setuid Programs and Their User IDs

>> Start, Stop, and Restart Nginx on Linux

>> The Exclamation Mark (!) in Interactive Shells

>> Linux Shells Performance: dash vs bash

>> How to Give Sudo Privileges to a User in Linux

>> Dealing with Frozen Windows and Desktop on Linux

>> Cannot Write to Directory Despite Having Group Permission in Linux

>> Managing Users and Groups in Linux

>> Bash, LAMP and LEMP Stack Professional (remote, part-time)(not open)

>> Find All Serial Devices on Linux Without Opening Them

>> Disassembling Machine Code in Linux

>> Different Ways of Running Jenkins in Linux

>> Managing gnome-terminal From the Command Line

>> What Do Identifiers Mean in Linux?

>> Check and Monitor Active GPU in Linux

>> Find Out What Symbols Are Exported From a DLL File on Linux

>> How Is the Linux Kernel Tested

>> Buffer and Cache Memory in Linux

>> View the List of Functions Exported by a Linux Shared Library

>> Find Out When a Linux System Was Installed

>> Find Swap Memory Usage by Processes in Linux

>> An Overview of ARM64, ARMel and ARMhf Processor Architectures

>> Linux envsubst Command with Examples

>> Remove Redundant Paths From the $PATH Variable

>> Substitute Shell Variables in a Text File

>> Redirect the Output of systemd Service to a File

>> Using the passwd Command from Within a Shell Script

>> Running a Linux Command on Start-Up

>> Setting the Vim Background Colors

>> Multiple glibc on a Single Linux Machine

>> Configure a Systemd Service to Restart Periodically

>> How To Disable User Logins On Linux

>> Find All Storage Devices Attached to a Linux Machine

>> Configuration Files in Linux

>> Linux Administration Guide

>> Fixing the “Command Not Found” Error When Using Sudo

>> Automating User Account Creation with Password in Shell

>> Check if an SMTP Server Is Working From the Linux Terminal

>> Empty the Buffer and Cache in Linux

>> Understanding Bind Mounts

>> Shell Script for Logging Into a SSH Server

>> The “Oldconfig” Target In The Linux Kernel Makefile

>> How to Show the wget Progress Bar Only?

>> How to Monitor Disk IO in a Linux System

>> Use sudo Command in Non-Interactive Mode

>> Fixing the “Too many open files” Error in Linux

>> GUI Under Linux

>> Linux Process States

>> Setting Command Timeouts in Bash

>> Linux in Virtual Machine vs. on Native Hardware

>> Including Additional Files in .bashrc

>> A Guide to POSIX

>> Understanding the /dev Directory in Linux

>> How to Run a Script at a Certain Time on Linux

>> Rotating Logs With Logrotate in Linux

>> Find the Graphics Card Version from the Command Line

>> Solving the “bad ELF interpreter” Error

>> Get Overall CPU Usage on Linux

>> Deploying Long Running Applications in Linux

>> Get the Number of Processors/Cores in Linux

>> “No such file or directory” Error When Executing a Binary

>> Determine the Current Shell in Linux

>> How to Create a CPU Spike in Bash

>> Network Failures Simulation in Linux

>> How to Find Which Process Was Killed by Linux OOM Killer

>> What’s the Difference Between sh and Bash?

>> Command Line Clipboard Access and Alternatives

>> Find Out the Total Physical Memory (RAM) on Linux

>> The Most Common Flags in /proc/cpuinfo with Examples

>> SSH Tunneling and Proxying

>> Copying SSH Keys To Another Machine

>> What are .a and .so Files?

>> tmux in Linux

>> How to Load Environment Variables in a Cron Job

>> Is My Disk SSD or HDD?

>> Find the Java SDK Location

>> How to Find All Links for a Specific File

>> Command Chaining: Inline or Already Running Processes

>> Kill All Members of a Process Group

>> How to Remove Symbolic Links

>> Mounting Remote Directory in Linux Using SSHFS

>> Remote File Synchronization in Linux

>> List All Groups in Linux

>> Changing the Default Shell in Linux

>> The strace Command in Linux

>> Bash HISTSIZE vs. HISTFILESIZE

>> How to Check Logs Using journalctl

>> Run a Java Application as a Service on Linux

>> How to Delete the History of the Last n Commands?

>> Monitoring Network Usage in Linux

>> Specify an Editor for Crontab

>> Run a Script on Startup in Linux

>> Mapping Hostnames with Ports in /etc/hosts

>> Encrypting and Decrypting Directory in Linux

>> Linux Interview Questions

>> Difference Between .bashrc, .bash-profile, and .profile

>> Why Should We Disable Root-login over SSH?

>> Preserve Bash History in Multiple Terminal Windows

>> Using the find -exec Command Option

>> Evolution of Docker from Linux Containers

>> Running Script or Command as Another User in Linux

>> How to Use the mysql Client and Related Utilities

>> How to Record Linux Terminal Sessions

>> How to Force Detach Screen From Another SSH Session

>> How to Change the Default Home Directory of a User

>> What does /opt mean in Linux?

>> Tracking Down Where Disk Space Has Gone on Linux

>> Linux Kernel Versions: 32-Bit vs 64-Bit

>> Easy Ways to Determine Virtualization Technology

>> Why Do We Use su – and Not Just su?

>> Configuring and Managing Core Dumps in Linux

>> Combine and Execute Multiple Linux Commands

>> Starting a Shell in the Alpine Docker Container

>> Managing Environment Variables in Linux

>> Sudo Command in Linux

>> How to Use Multiple Databases with docker-compose

>> Locale Environment Variables in Linux

>> Display System Information in the CLI with Neofetch

>> Free Command in Linux

>> Guide to the Linux screen Command

>> How to Determine the Number of RAM Slots in Use

>> Linux man Command

>> Linux last Command

>> Shut Down and Reboot Linux Systems From the Terminal