Comptia Linux+ course

fstab (File System Table)

A configuration table designed to ease the burden of mounting and unmounting file systems to a machine.

vim

A basic GUI based text editor that comes with distribution of Linux, BSD, and MacOS.

nmcli (Network Manager Command Line Interface)

A command-line tool used for controlling NetworkManager and reporting network status.

du (Disk Usage)

Unix/Linux command used to check disk usage of files and directories on a system.

xfs (High Performance Scalable File System)

A high-performing, 64-bit journaling Linux file system originally created by Silicon Graphics.

cp (Copy)

A Unix/Linux command that allows for the copying of files from one location to another.

rm (Remove)

A Unix/Linux command that allows for the removal of files from one location to another.

mkdir (Make Directory)

A Unix/Linux command that creates or "makes" a directory within a File System.

mv (Move)

A Unix/Linux command that moves a selected file from one location to another.

df (Disk Free)

A Unix/Linux command that displays the amount of disk space available on the filesystem.

exFAT (Extended File Allocation Table)

A 64-bit version of the file allocation table file system designed for use on large USB flash drives.

ext4 (Extended File System 4)1

A file system designed for Linux platforms as a successor to the previous version, that allows for standard functions such as formatting volumes, drives, and other computing storage solutions.

SSH (Secure Shell)

A cryptographic network protocol for operating network services securely over an unsecured network. Uses Port 22 TCP.

enable

A Linux process to have a process open upon system startup.

start

A Linux command to start a process upon it's demand.

restart

A Linux command to restart a process upon command.

stop

A Linux command to stop a process upon command.

udevadm (Udev Management Tool)

A device management tool in Linux which manages all the device events and controls the udevd daemon.

systemctl (System Control Temporal Logic)

Manages both system and service configuration, enabling administration to manage the OS and control the stats of services.

systemd

A software suite that provides an array of system components for Linux operating systems with the aim to unify service configuration and behavior across Linux Distributions.

firewalld

A firewall management tool for Linux to provide firewall features; acting as the front-end of the Linux kernel's netfilter framework.

ps (Process Status)

A Linux command that displays information related to running processes.

iostat (Input/Output Statistics)

A Linux monitor tool used to collect and show operating system storage input and output statistics.

arp (Address Resolution Protocol)

A Linux command that allows users to manipulate the neighbor cache or ARP table.

ls (List)

Linux command that lists the files and sub-directories in the current directory.

ping

Sends a message from one computer to another to check whether it is reachable and active.

timedatectl

Linux command used to set and change system clock settings and enable or disable time synchronization services.

ntp (Network Time Protocol)

An internet protocol used to synchronize with computer clock time sources in a network. Runs off of Port 123 UDP.

telnet

A network protocol that allows a user on one computer to log into another computer that is part of the same network. Not secured at all. Runs off of Port 23 TCP.

host

A Linux command used to find a variety of information through Domain Name System (DNS).

dpkg (Debian Package)

A medium-level too to install, build, remove, and manage Debian Linux packages.

rpm (Red Hat Package Manager)

A package manager developed for Red Hat/Fedora distributions of Linux.

zypp

An open-source package manager engine for certain Linux applications, meant for openSUSE and SUSE Linux Enterprise.

apt (Advanced Packaging Tool)

A Ubuntu based packaging tool meant for installing new software packages, upgrading existing packages, updating package list indexes, and upgrading entire Ubuntu systems.

.deb

A file format for software packages, meant for Debian Linux Distributions and their derivatives.

yum (Yellowdog Updater, Modified)

The primary package management tool for installing, updating, removing, and managing software packages in Red Hat Enterprise Linux.

cron

A method to automatically run commands on a schedule within Linux.

/etc/yum.repos.d

Linux Directory that contains um configuration files (.repo files), which contain the URL to servers to fetch packages from.

/var/log/secure

Linux Directory meant to keep authentication logs for both successful or failed logins, and authentication processes.

modprobe (Module Probe)

A Linux program used to add or a loadable kernel module to the Linux kernel.

ioping (Input/Output Ping)

A Linux command used to monitor I/O latency in real time, showing disk latency the same way as the ping command showing network latency.

lsmod (List Modules)

A Linux command used to display the status of modules in the Linux kernel.

depmod (Dependency Modules)

A Linux command used to generate a list of dependency descriptions of kernel modules and its associated map files.

LDAP (Lightweight Directory Access Protocol)

An open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed directory information services over an Internet Protocol network.

PAM (Pluggable Authentication Modules)

A suite of libraries that allows a Linux system administrator to configure methods to authenticate users.

Public Key (Asymmetric) Encryption

A large numerical value that is used to encrypt data.

Private Key (Symmetric) Encryption

A cryptographic key that is used with an asymmetric cryptographic algorithm.

PKI (Public Key Infrastructure)

A combination of policies, procedures and technology needed to manage digital certificates in a public key cryptography scheme.

/etc/skel

A Linux directory that contains files and directories that are automatically copied over to new user's when it is created from the useradd command.

/etc/bashrc

A Linux directory that contains system-wide functions and aliases including other configurations that apply to all system users.

/var/logs

A Linux directory meant for storing logs within the LinuxOS.

/dev/sda#

The directory for a specific drive within Linux.

chown (Change Owner)

A Unix/Linux command used to change the owner of file system files or directories.

chgrp (Change Group)

A Unix/Linux command used to change the group that a user is associated with.

chage (Change Age)

A Linux command used to change the number of days between password changes.

chmod (Change Mode)

A Unix/Linux command used to change access permissions of file system objects.

useradd (User Add)

A Linux command used to create a new user.

usermod (User Modify)

A Linux command used to modify an existing user.

userdel (User Delete)

A Linux command used to remove or delete a user.

passwd (Password)

A Linux command used to change the password on a user account.

Self-Signed Certificate

Public-Key Certificates that are not issued by a certificate authority.

Sticky Bit

A bit set on directories that allows only the owner or root to delete certain files and subdirectories.

ssh-keygen (Secure Shell Key Generation)

A Linux tool used for creating new authentication key pairs for SSH.

chroot jail (Change Root Jail)

An artificial root directory used to limit the directory access of a potential attacker.

SUID (Set-User Identification)

A special file permission for executable files that enables other users to run the file with the same permissions as the file owner.

SGID (Set Group Identification)

A special file permission that enaables other users to inherit the effective group identifier of a group owner.

/etc/sudoers

A file that Unix/Linux administrators use to allocate system rights to system users.

Port Forwarding

The process of redirecting traffic from its normally assigned port to a different port, either on the client or server.

nano

A Linux text editor within a command-line interface.

visudo (Vim Sudo)

A text editor for specifically the sudoers file, conducting multiple sanity and error checks constantly.

gedit (GNOME Edit)

The default text editor for GNOME desktop environments in Linux.

getfacl (Get File Access Control Lists)

Linux Command that displays the filename, owner, group, an Access Control List.

setfacl (Set File Access Control Lists)

Linux command that sets the Access Control Lists of files and directories.

>

Redirects a system output to the end of a file instead of the standard output.

echo

Linux command that repeats back what a user specifies (ex. Print Function).

stdout (Standard Output)

The default file descriptor where a process can write output.

PATH

An environment variable that instructs a Linux system in which directories to search executables.

docker

An open software platform that allows you to build, test, and deploy applications quickly.

docker info

Docker command that displays system wide information regarding docker installations.

docker ps (docker process status)

Docker command that shows the status of docker containers.

docker pull

Docker command that downloads a Docker images from the internet.

docker push

Docker command that uploads Docker images to the internet.

docker logs

Docker command that fetches the logs of Docker containers.

Container

A standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another.

Container Image

A static file with executable code that can create a container on a computing system.

Container Engine

Cluster management and container orchestration system developed to run and manage Docker containers.

git

A distributed version control system that tracks changes in any set of computer files.

checkout

Git command that tells which branch or commit you want your changes applied to.

YAML

Human-readable data serialization language commonly used for configuration files and some applications.

merge (git)

Git's way of putting a forked history back together again.

Samba

The standard Windows interoperability suite of programs for Linux and Unix.

Orchestration

The automation of deployment, management, scaling, and networking of containers.

Service Mesh

A dedicated infrastructure layer that controls service-to-service communication over a network.

Container Registry

A repository or collection of repositories used to store and access container images.

du / (Disk Usage /)

Linux command that displays the number of blocks for each file or directory within a system.

ls / (List /)

Linux command that displays the names and features of files and directories.

ulimit (

A Linux command that provides a way to get and set process resource limits.

noop (No Operation)

The simplest I/O schedule for the Linux kernel that inserts all incoming I/O requests into a simple FIFO (First-In/First-Out) queue and implements request merging.

lvm (Logical Volume Management)

Storage virtualization that offers system administrators a more flexible approach to managing disk storage space than traditional partitoning.

lvcreate (Logical Volume Create)

Linux command that creates a new logical volume in a volume group.