Commands

Basic Ubuntu commands and terminal shortcuts every beginner must know

What you'll need. A computer running Ubuntu or some other version of Linux. Every Linux system includes a command line of one sort or another. 

Let's see some important and commonly used commands in Linux:

1. Ls

ls (list) command lists all files and folders in your current working directory. You can also specify paths to other directories if you want to view their contents.

2. Cd      

cd (change director”) Linux command also known as chdir used to change the current working directory. It’s one of the most used basic Ubuntu commands. Using this command is easy, just type cd followed by the the folder name. You can use full paths to folders or simply the name of a folder within the directory you are currently working. Some common uses are:

·         cd /  – Takes you to the root directory.

·         cd .. – Takes you up one directory level.

·         cd –  – Takes you to the previous directory.

Here are some examples to how to use cd command in Ubuntu:

Example 1: cd home – open home folder in current directory.

Example 2: cd Linux\ Drive – open Linux Drive named folder in directory. Here you can see I use backslash because the folder name has spaces so for each space you use “backslash+space”. Like, if your folder name is “am a programmer” then the cd command will be, “cd am\ a\ programmer”.

3. Pwd

pwd (print working directory) Ubuntu command displays the full pathname of the current working directory.

4. Cp

cp (copy) Linux command allows you to copy a file. You should specify both the file you want to be copied and the location you want it copied to – for example, cp xyz /home/myfiles would copy the file “xyz” to the directory “/home/myfiles”.

5. Mv

mv (move) command allows you to move files. You can also rename files by moving them to the directory they are currently in, but under a new name. The usage is the same as cp – for example mv xyz /home/myfiles would move the file “xyz” to the directory “/home/myfiles”.

6. Rm

rm (remove) command removes the specified file.

·         rmdir (“remove directory”) – Removes an empty directory.

·         rm -r (“remove recursively”) – Removes a directory along with its content.

7. Mkdir

mkdir (make directory) command allows you to create a new directory. You can specify where you want the directory created – if you do not do so, it will be created in your current working directory.

8. History

history command displays all of your previous commands up to the history limit.

9. Df

df (display filesystem) command displays information about the disk space usage of all mounted filesystems.

10. Du

du (directory usage) command displays the size of a directory and all of its subdirectories.

11. Free

free – Displays the amount of free space available on the system.

12. Uname -A

uname -a – Provides a wide range of basic information about the system.

13. Top

top – Displays the processes using the most system resources at any given time. “q” can be used to exit.

14. Man

man command displays a “manual page”. Manual pages are usually very detailed, and it’s recommended that you read the man pages for any command you are unfamiliar with. Some uses are :

·         man man – Provides information about the manual itself.

·         man intro – Displays a brief introduction to Linux commands.

15. Info

Similar to man, but often provides more detailed or precise information.

16. <Command Name> -H Or <Command Name> –Help

This command is a third alternative to get help. While not as detailed as the info or man pages, this will provide a quick overview of the command and its uses.

For example: man -h or man -help

17. Passwd

passwd Ubuntu basic command is used to change user password using Terminal. What you have to do is run the below command, where is the username whose password has to change:

passwd <user>

18. Whatis

whatis command shows a brief description of what is the functionality of specific built-in Linux command.

whatis <command>

Some examples are:

·         whatis cd

·         whatis man

·         whatis help

Above commands will display the purpose of cd, man and help commands.

Ubuntu Terminal Keyboard Shortcuts:

Ubuntu Terminal Shortcuts	Function
Ctrl + Shift + T	Open new tab on current terminal
Ctrl + Shift + W	Close the current tab
Ctrl + A	Move cursor to beginning of line
Ctrl + E	Move cursor to end of line
Ctrl + U	Clears the entire current line
Ctrl + K	Clears the command from the cursor right
Ctrl + W	Delete the word before the cursor
Ctrl + R	Allows you to search your history for commands matching what you have typed
Ctrl + C	Kill the current process
Ctrl + Z	Suspend the current process by sending the signal SIGSTOP
Ctrl + L	Clears the terminal output
Alt + F	Move forward one word
Alt + B	Move backward one word
Ctrl + Shift + C	Copy the highlighted command to the clipboard
Ctrl + Shift + V or Shift + Insert	Paste the contents of the clipboard
Up/Down Arrow keys	To scroll through your command history, allowing you to quickly execute the same command multiple times
TAB	Used to complete the command you are typing. If more than one command is possible, you can press it multiple times to scroll through the possible completions. If a very wide number of commands are possible, it can output a list of all possible completions.