Basic Bash commands allow users to navigate through a system and effectively manage files, directories, and different data types. This article will list 30 Bash commands and provide you with a downloadable PDF cheat sheet to always have them at hand. Note: Check out our guide to Linux shells.Learn how to use various Ubuntu commands for desktop environments, file management, software installation and removal, networking, and more. See examples of commands and their usage in different scenarios.Here’s a cheat sheet for Linux network configuration commands that we can use to set up and manage a variety of network settings. Tasks related to network configuration include setting up network interfaces, allocating IP addresses, configuring DNS settings, setting up routing, and managing network security: Command. Description.29. chown command. The chown command lets you change a file, directory, or symbolic link’s ownership to the specified username. Here’s the syntax: chown [option] owner[:group] file(s) For example, to make linuxuser2 the owner of filename.txt, use: chown linuxuser2 filename.txt.Create a new file with cat command. You can use following syntax to create a new file and add some data using cat command in Linux or Unix. bash. cat >FILENAME. For example, here I will create a new file cars.txt and add some content to this file. First we will check, we don't have any existing file with the same name: APT Cheat Sheet. APT" stands for "Advanced Package Tool." APT is a package management system used by Debian and its derivatives, such as Ubuntu, to handle the installation, upgrade, and removal of software packages. It simplifies the process of managing software on Unix-like operating systems by automatically resolving dependencies, retrieving ... In this cheat sheet you will find a bunch of the most common Linux commands that you're likely to use on a regular basis. On most systems you can lookup detailed information about any command by typing man command_name. You will need to be root user in order to use some of these commands. Be extremely careful as root if …Cheat Sheet (Aide-mémoire) des Commandes Linux. indique le répertoire de travail actuel. navigue dans les fichiers et les répertoires. cd.. monte d'un répertoire. retourne au répertoire précédent. crée un ou plusieurs répertoires. supprime un répertoire vide. copie en toute sécurité un fichier spécifique dans un répertoire du serveur.Ubuntu 20.04 Server - Setup, Installation, Hardening and Commands. - Motyldrogi/ubuntu-cheat-sheetCribbage is a classic card game that has been enjoyed by people of all ages for centuries. Whether you’re a seasoned player or new to the game, having a reliable resource for cribb...Jul 22, 2020 · The basic keys for moving the cursor by one character are: h – move the cursor left. j – move the cursor down. k – move the cursor up. l – move the cursor right. You can also use these keys with a number as a prefix to move in a specified direction multiple times. For example, if you run 5j the cursor moves down 5 lines. skip to content; cmdref.net - Cheat Sheet and Example. cmdref.net is command references/cheat sheets/examples for system engineers.Mar 16, 2024 ... 1. Navigating the File System ... – List directory contents. ... – Change directory. ... – Print the current working directory. – Example: `pwd`. 2.Ctrl + b ". Split the current with a horizontal line to create a vertical layout. : join-pane -s 2 -t 1. Join two windows as panes (Merge window 2 to window 1 as panes) : join-pane -s 2.1 -t 1.0. Move pane from one window to another (Move pane 1 from window 2 to pane after 0 of window 1) Ctrl + b {. Move the current pane left.Arch Linux has multiple commands to create, manage, and extract files and directories from compressed archives. The most useful commands of this type are listed below: Commands. Description. zip. Create and manipulate ZIP archive files. tar. Archive and compress files.<https://www.canonical.com> Overview. A brief history lesson. Opening a terminal. Creating folders and files. Moving and manipulating files. A bit of plumbing. The command line … Common commands and installation basics I need to remember. doublehelix. 13 Mar 19, updated 9 Apr 19. linux, ubuntu, -nix. 2 Pages. (0) [BASH] Windows Integrated Ubuntu Terminal Cheat Sheet. Some small tips on the basic of WSL 2 (Windows' Ubuntu). Try to create your very first PowerShell (bash). Here is quick cheat sheet you will find handy while using apt-get at shell prompt: Syntax. Description. Example (s) apt-get install {package} Install the new package. If package is installed then try to upgrade to latest version. apt-get install zip. apt-get install lsof samba mysql-client.APT Cheat Sheet. APT" stands for "Advanced Package Tool." APT is a package management system used by Debian and its derivatives, such as Ubuntu, to handle the installation, upgrade, and removal of software packages. It simplifies the process of managing software on Unix-like operating systems by automatically resolving dependencies, retrieving ...Optimizing the platform’s functionality begins with mastery of the core Docker commands. This cheat sheet is a reference for the most basic Docker commands that address installation, Hub interaction, and working with containers and images. As of this writing, the recommended Docker installation is Docker Community Edition .29. chown command. The chown command lets you change a file, directory, or symbolic link’s ownership to the specified username. Here’s the syntax: chown [option] owner[:group] file(s) For example, to make linuxuser2 the owner of filename.txt, use: chown linuxuser2 filename.txt.Linux Commands Cheat Sheet Hardware Information File Compression Package Installation dmesg cat /proc/cpuinfo free -h lshw lsblk lspci -tv lsusb -tv dmidecode hdparm -i /dev/[disk] hdparm -tT /dev/[disk] badblocks -s /dev/[disk] tar cf [le.tar] [le] tar xf [le.tar] tar czf [le.tar.gz] gzip [le] Show bootup messages Show CPU information Show ...ps process status command is used to provide inform ation about the processes currently running on the system, including their respective process identi fic ation numbers (PIDs). uptime inform ation about how long the system has been running in one line. Result for this command includes the current time, the time duration system has been runningWhether you're a newbie or an experienced pro in need of a quick reference, this cheat sheet has got you covered. This PostgreSQL Cheat Sheet summarizes the key PostgreSQL commands and features you'll use often. It covers everything from how to connect to a PostgreSQL server and manage database contents, to the basic syntax for …Capturing precious moments in photographs is a timeless tradition that allows us to relive our memories and share them with others. When it comes to printing these photographs, the...Lock (password protect) display. Ctrl-A : Enter screen command. Ctrl-A H. Enable logging in the screen session. Screen tricks. SSH and attach in one line. $ ssh -t user@host screen -x <name/pid>. This is a quick reference guide cheat sheet for the screen command.Keybindings Cheat Sheet. 1. Installing tmux. Below are the commands for installing tmux on various Linux distributions, as well as for Mac and BSD systems: bash. # Debian/Ubuntu. sudo apt-get install tmux. # Fedora. sudo dnf install tmux.May 2, 2024 · chattr changes the file attributes on a Linux file system. chattr examples. # chattr +i /tmp/file. In this example we have restricted the modification permission on /tmp/file. Now not even root user can modify the content of /tmp/file. To remove this permission use chattr -i /tmp/file. lsattr. Ubuntu 18.04 Server Configuration Cheat Sheet by doublehelix. Common commands and installation basics I need to remember. Ubuntu Server 18.04. apt - Advanced Packaging Tool ... Linux Command Line Cheat Sheet , , , , Ubuntu Unity Cheat Sheet, , , Windows Terminal Cheat Sheet, , , , More Cheat Sheets by doublehelix ...Mar 5, 2023 ... Basic Linux Commands Cheat Sheet · ls · cd: Change directory to a different directory. Example: cd /home/user/documents ; Advanced Linux Commands ...vi Editor “Cheat Sheet”. Invoking vi: vi filename Format of vi commands: [count][command] (count repeats the effect of the command) Deletion commands. dd or ndd Delete n lines to general buffer dw Delete word to general buffer dnw Delete n words d) Delete to end of sentence db Delete previous word D Delete to end of line x Delete … Basic Ubuntu Commands And Terminal Shortcuts (Cheat Sheet). First of all, Ubuntu is overwhelming, especially if you’re not familiar with using a terminal. After all, the Ubuntu terminal is the best way to interact with the system and execute tasks. Nov 4, 2020 ... This video reviews canonical's new Ubuntu Server CLI Pro Tips Cheatsheet and shows how it is a useful tool for every Network Server ...2. apt-get. The apt-get is one of the most important commands of Ubuntu, and that every beginner should know. It is used to install, update and remove any package. apt-get basically works on a database of available packages. Here is the list of different apt-get commands: sudo apt-get update. apt-get update with administrator privileges is the ...For RHEL/CentOS 8 and Fedora systems, use the dnf command to install Nginx. $ sudo dnf install -y nginx. For Debian based systems, use the apt command or apt-get command to install Nginx. $ sudo apt install nginx. or. $ sudo apt-get install nginx. For openSUSE systems, use the zypper command to install Nginx. $ sudo zypper install -y …Dec 27, 2023 · Use these essential commands for moving around the filesystem: pwd – print name of current/working directory. ls – list directory contents. cd – change directory. file – determine file type. du – estimate file space usage. df – report disk usage statistics. mkdir – create directories. To start with shell scripting, you need to create a shell script file. This is a simple text file with a .sh extension which contains shell commands. The first line of your script should be the shebang ( #!/bin/bash) which tells the system which interpreter to use to execute the file’s contents. #!/bin/bash. echo "Hello, World!"Advertisement Advertisement Please copy/paste the following text to properly cite this HowStuffWorks.com article: Advertisement Advertisement Advertisement Here is a quick cheat sheet you will find handy while using dpkg at shell prompt: Syntax. Description. Example. dpkg -i {.deb package} Install the package. dpkg -i zip_2.31-3_i386.deb. dpkg -i {.deb package} Upgrade package if it is installed else install a fresh copy of package. Take advantage of all available resources, including books, cheat sheets, web search, stack exchange, etc. Also, don’t forget the built in help available from the command line. Using ‘tar’ as an example utility you’re trying to learn about, try each of these before hitting the browser: $ man tar. $ info tar. $ tar —help.Overview #. UFW (uncomplicated firewall) is a firewall configuration tool that runs on top of iptables, included by default within Ubuntu distributions.It provides a streamlined interface for configuring common firewall use cases via the command line. This cheat sheet-style guide provides a quick reference to common UFW use cases and …Use the following hotkeys within the Linux shell: ctrl + c – terminate the currently running command. ctrl + r – search the current terminal session’s command history. ctrl + a – go to the start of line (useful if you need to correct a typo at the beginning of a very long command) ctrl + e – go the the end of line. ctrl + z – sleep ...Linux Commands Cheat Sheet Hardware Information File Compression Package Installation dmesg cat /proc/cpuinfo free -h lshw lsblk lspci -tv lsusb -tv dmidecode hdparm -i /dev/[disk] hdparm -tT /dev/[disk] badblocks -s /dev/[disk] tar cf [le.tar] [le] tar xf [le.tar] tar czf [le.tar.gz] gzip [le] Show bootup messages Show CPU information Show ...Use the following hotkeys within the Linux shell: ctrl + c – terminate the currently running command. ctrl + r – search the current terminal session’s command history. ctrl + a – go to the start of line (useful if you need to correct a typo at the beginning of a very long command) ctrl + e – go the the end of line. ctrl + z – sleep ...50 Basic Ubuntu Commands with Examples; Basic Ubuntu Commands Cheat Sheet. Dive deep into the heart of Ubuntu basic commands cheat sheet with this comprehensive compilation of 50 Basic Commands, each accompanied by practical examples to illuminate their functionality. Whether you're a Linux enthusiast or a novice … Cheat Sheet (Aide-mémoire) des Commandes Linux. indique le répertoire de travail actuel. navigue dans les fichiers et les répertoires. cd.. monte d'un répertoire. retourne au répertoire précédent. crée un ou plusieurs répertoires. supprime un répertoire vide. copie en toute sécurité un fichier spécifique dans un répertoire du serveur. Further useful Ubuntu copy is ‘apt autoremove’. The autoremove command cleans up Ubuntu packages left past during the (sometimes) incomplete uninstall process mentioned above. Example Usage: Linux command syntax may shine difficult to remember. How our Linux Command Cheat Sheet. All the key commands in only pdf. apt autoremove A list of essential Linux commands for Ubuntu users, with descriptions and examples. Learn how to create, copy, move, edit, and manage files and directories, …A comprehensive list of Linux commands sorted by category, such as file system, administration, networking, and more. Learn Linux commands with examples …Learn the basics of the Linux command line, a text interface to your computer, with this tutorial. You'll cover some history, file manipulation, chaining commands, and administrator powers.Nick Schäferhoff Editor in Chief Below you can find the Javascript cheat sheet in .pdf as well as in the text. If you find any errors in this sheet, please contact us – [email protected] Linux Commands Wallpaper HD Wallpaper">. Get Wallpaper. 1920x1080 Download 1920x1080 Linux, Cli Commands Wallpaper for Widescreen">. Get Wallpaper. 1680x1050 Free download Command line cheat sheet LinuxBloggendk [2195x1756] for your Desktop, Mobile & Tablet. Explore Linux Command Wallpaper.This is a JPG image, download the PDF below to retain the clickable hyperlinks. Click on the image above to open the Kali Linux Cheat Sheet PDF in a new window. Each tool’s name is a link through a website that explains the functions of the utility. The tools that we will look at in this guide are:The command-line interface might seem daunting initially, but trust me, it’s where the real magic happens. This guide on “Linux Commands Cheat Sheet” will dive into a collection of essential Linux commands that will turn you into a …Use the usermod -u command to change the user ID of a user. This is my cheat sheet on Linux user administration covering functions such as adding, and removing users and assigning them to groups. Add a new Linux user Use the useradd command to add a new user. useradd [USERNAME] Change a users password The user account is …Ubuntu Reference Privileges sudo command – run command as root sudo -s – open a root shell sudo -s -u user – open a shell as user sudo -k – forget sudo passwords gksudo command – visual sudo dialog (GNOME) kdesudo command – visual sudo dialog (KDE) sudo visudo – edit /etc/sudoers gksudo nautilus – root fle manager (GNOME) kdesudo …The most comprehensive OpenStack cheat sheet for beginners and more advanced users. Keystone. Glance. Neutron. Nova. Cinder. Get the OpenStack cheat sheet. Instances (Nova), networks (Neutron), images (Glance), volumes (Cinder), identities (Keystone) and much more. Get started with OpenStack quickly. Ubuntu Command Reference Cheat Sheet - Free download as PDF File (.pdf), Text File (.txt) or read online for free. This document provides a summary of common commands and configuration files used in Ubuntu systems for privileges, networking, display settings, package management, applications, services, and system recovery. Quick manual access to the use of SSH can be accessed by running the following command on your Linux terminal: $ ssh. SSH Usage and Options. To edit your SSH configurations like access port and connection timeout, you will need to access the configuration file /etc/ssh/ssh_config or /etc/ssh/sshd_config. $ sudo nano …Mar 15, 2024 ... Ubuntu is one of the most popular distributions of Linux, known for its user-friendly interface and robust features. · This command lists the ...9. The Unix and GNU/Linux command line. This Unix and Linux command cheat sheet is an all-in-one container that covers a lot of Terminal commands, including shells, filesystem, and file handling; standard I/O, redirections, pipes; task control and code editors, etc. Download The Unix and GNU/Linux command line. 10.Ubuntu Commands Cheat Sheet. Raw. commands.txt. # Commands to backup a website from root access to ssh with mysql database. cd to directory of website. # Compress. tar czf filename.tar.gz *. mysqldump -u root -ppassword databasename | gzip -9 > filename.sql.gz.This cheat sheet is intended to be a quick reminder for the main concepts involved in using the command line program Vim (or vi) and assumes you already understand its usage. It does not cover every command in Vim, only the ones we consider to be useful for most people for the majority of their text editing.Aug 24, 2023 · Basic Bash commands allow users to navigate through a system and effectively manage files, directories, and different data types. This article will list 30 Bash commands and provide you with a downloadable PDF cheat sheet to always have them at hand. Note: Check out our guide to Linux shells. 29. chown command. The chown command lets you change a file, directory, or symbolic link’s ownership to the specified username. Here’s the syntax: chown [option] owner[:group] file(s) For example, to make linuxuser2 the owner of filename.txt, use: chown linuxuser2 filename.txt.Re: Linux Commands Cheat Sheet. Sat Jun 02, 2012 10:37 am. Thanks for the link! One command left off that list, which I (luckily) ...Keybindings Cheat Sheet. 1. Installing tmux. Below are the commands for installing tmux on various Linux distributions, as well as for Mac and BSD systems: bash. # Debian/Ubuntu. sudo apt-get install tmux. # Fedora. sudo dnf install tmux.Apr 15, 2022 · ubuntu@ubuntu:~# sudo snap find tautulli Name Version Publisher Notes Summary tautulli v2.9.7 jonnywong16 - A Python based monitoring and tracking tool for Plex Media Server. Install snap packages. To install one of the packages, use the following command. ubuntu@ubuntu:~# sudo snap install tautulli List snap packages. Use the snap list command Are you in the market for new appliances? Whether you’re upgrading your kitchen or replacing a worn-out washer and dryer, finding the best deals on appliances is crucial. Best Buy,...A comprehensive list of Linux commands sorted by category, such as file system, administration, networking, and more. Learn Linux commands with examples …If you don't know the start size while creating a partition, you can fill the disk to the end using 100%. ALSO READ. 100+ Linux commands cheat sheet & examples. For example, to create a primary partition of 5GB, you can use the command below. bash. $ sudo parted /dev/sda mkpart primary 5000 100%.MySQL Commands. Below you will find a list of commonly used MySQL commands and their definitions. To see a full list of commands, please refer to the MySQL Cheat Sheet included at the bottom of the article. Users and Privileges. Display the current user name and hostname: USER() Create a MySQL user: CREATE USER 'user'@'host';Ubuntu Commands Cheat Sheet. Raw. commands.txt. # Commands to backup a website from root access to ssh with mysql database. cd to directory of website. # Compress. tar czf filename.tar.gz *. mysqldump -u root -ppassword databasename | gzip -9 > filename.sql.gz.Feb 22, 2018 · sudo. e.g. sudo ls. Update Advanced Packaging Tool (APT) package manager – retrieves latest package list. sudo apt-get update. Install software package. sudo apt-get install [package name] e.g. sudo apt-get install vlc. Update currently installed software package. Note: this is done by tying together both the apt update and install commands. Just want the cheatsheet? No problem! Please enjoy and if you'd like to submit any suggestions, feel free to email us at [email protected]. Contents. The Linux …Not quite what you are looking for, but cheat.sh is a very nice thing. This is an universal cheat sheet for almost anything, not only Linux terminal commands but also many programming languages etc. This is an universal cheat sheet for almost anything, not only Linux terminal commands but also many programming languages etc.Sep 26, 2018 ... Linux Command Cheatsheet: Disk usage and filesize cheatsheet Table of contents · df - report file system disk space usage (show total hard drive ...Create a new file with cat command. You can use following syntax to create a new file and add some data using cat command in Linux or Unix. bash. cat >FILENAME. For example, here I will create a new file cars.txt and add some content to this file. First we will check, we don't have any existing file with the same name:Mar 5, 2023 ... Basic Linux Commands Cheat Sheet · ls · cd: Change directory to a different directory. Example: cd /home/user/documents ; Advanced Linux Commands ...Cheat Sheet for apt-get commands. Update and Upgrade. sudo apt-get update. Updates the package database. sudo apt-get upgrade <package>. Upgrades an already installed package. sudo apt-get update && sudo apt-get upgrade …Execution the last command again:!! Report out of current training: output. Conclusion. The more you use Linux commands, the better you intention get at remembering diehards. Do does emphasize nearly memorizing their syntax; use our cheat sheet. Whenever in mistrust, refer to those helpful guide for the mostly common Linux commands.Networking command. Command. Description. SSH username@ip-address or hostname. login into a remote Linux machine using SSH. Ping hostname="" or ="". To ping and Analyzing network and host connections. dir. Display files in the current directory of a remote computer.$1 Value of first command line parameter (similarly $2, $3, etc) $# In a shell script, the number of command line parameters. $* All of the command line parameters. $- Options given to the shell. $? Return the exit status of the last command.This is a JPG image, download the PDF below to retain the clickable hyperlinks. Click on the image above to open the Kali Linux Cheat Sheet PDF in a new window. Each tool’s name is a link through a website that explains the functions of the utility. The tools that we will look at in this guide are:Linux Keyboard shortcuts. open terminal: Ctrl+Alt+T. Ctrl + C is used to kill a process with signal SIGINT , in other words it is a polite kill . Ctrl + Z is used to suspend a process by sending it the signal SIGTSTP , which is like a sleep signal, that can be undone and the process can be resumed again. Ctrl+D: log out of current session ...
Use the following hotkeys within the Linux shell: ctrl + c – terminate the currently running command. ctrl + r – search the current terminal session’s command history. ctrl + a – go to the start of line (useful if you need to correct a typo at the beginning of a very long command) ctrl + e – go the the end of line. ctrl + z – sleep .... Dte energy bill payment
The AWS Command Line Interface is a unified tool that provides a consistent interface for interacting with all parts of AWS. Command Reference. accessanalyzer. account. acm. acm-pca. alexaforbusiness. amp. amplify.Keyboard Shortcuts. TAB TAB: Display all commands or filenames starting with written letters. CTRL + L: Clear the current line. CTRL + D: Close the shell. CTRL + U: Cut the current line. CTRL + A: Move cursor to start of the line. Ctrl + E: Move cursor to the end of the line. CTRL + C: Stop the current command.Dec 14, 2023 · Dive deep into the heart of Ubuntu basic commands cheat sheet with this comprehensive compilation of 50 Basic Commands, each accompanied by practical examples to illuminate their functionality. Whether you're a Linux enthusiast or a novice looking to expand your command-line repertoire, this guide will equip you with an extensive toolkit to ... Are you struggling to find the right international journals for your research? Don’t worry, you’re not alone. Many researchers face challenges when it comes to searching for releva...Lock (password protect) display. Ctrl-A : Enter screen command. Ctrl-A H. Enable logging in the screen session. Screen tricks. SSH and attach in one line. $ ssh -t user@host screen -x <name/pid>. This is a quick reference guide cheat sheet for the screen command.29. chown command. The chown command lets you change a file, directory, or symbolic link’s ownership to the specified username. Here’s the syntax: chown [option] owner[:group] file(s) For example, to make linuxuser2 the owner of filename.txt, use: chown linuxuser2 filename.txt.Linux Commands Cheat Sheet Hardware Information File Compression Package Installation dmesg cat /proc/cpuinfo free -h lshw lsblk lspci -tv lsusb -tv dmidecode hdparm -i /dev/[disk] hdparm -tT /dev/[disk] badblocks -s /dev/[disk] tar cf [le.tar] [le] tar xf [le.tar] tar czf [le.tar.gz] gzip [le] Show bootup messages Show CPU information Show ...Apr 29, 2021 ... This Ubuntu Server CLI Cheat Sheet is a compilation of commands for administering everything from the network, security, packages, files, ...Quick manual access to the use of SSH can be accessed by running the following command on your Linux terminal: $ ssh. SSH Usage and Options. To edit your SSH configurations like access port and connection timeout, you will need to access the configuration file /etc/ssh/ssh_config or /etc/ssh/sshd_config. $ sudo nano …Basic Linux Commands Cheatsheets. Red Hat Linux Commands Cheat Sheet ; Networking Command Cheat Sheets. Linux Networking Commands ; Bash Scripting Cheat Sheets.A detailed SQL cheat sheet with essential references for keywords, data types, operators, functions, indexes, keys, and lots more. For beginners and beyond. Luke Harrison Web Devel...root@ubuntu:~ # sort -n file.txt. The above command will sort the lines in file.txt in numerical order. The sort command can also be used to sort lines based on specific fields using the -k option. Here’s an example of using the -k option: root@ubuntu:~ # sort -k 2 file.txt. This command will sort the lines in file.txt based on the second field.Download the Ubuntu Generic Commands Cheat Sheet. 1 Page. PDF (recommended) PDF (1 page) Alternative Downloads. PDF (black and white) LaTeX Latest Cheat Sheet. 1 Page (0) ERP System Selection Cheatsheet Cheat Sheet. Use this cheatsheet as a guideline to systematically evaluate and select the ERP system that best suits the needs …Navigate Linux ip with this cheat sheet. This cheat sheet includes: ip queries. Multicast addressing. Modifying address and link properties. Adjusting and viewing routes. Managing the ARP table. And more. Download this Linux command cheat sheet in an easy-to-read and ready-to-print format.Useful commands in Ubuntu Linux. This list provides some simple command line examples. To open a terminal emulator window, click the Gnome Applications menu and select Accessories → Terminal, then, use these commands: clear Clears the current screen of all text. ls Lists the current directory. It’s like the MS-DOS dir …This cheat sheet covers all the basic and advanced commands, including file and directory commands, file permission commands, file compression and archiving, process management, system information, networking, and more with proper examples and descriptions. In addition to that we provide all the most used Linux Shortcut which includes Bash ...Oct 19, 2023 — Sagar Sharma. 25 Must-Know Ubuntu Commands. What are the top Ubuntu commands that everyone should know? There is no set answer to that. It differs from person to person, based on their need. In this tutorial, I will share my list of 25 Linux commands I think all Ubuntu users should know. Must know Ubuntu commands..