Basic Linux Commands

Summary

When managing a Linux server, make a habit of checking your current location and target, running one command at a time, and verifying the result. Start with commands for working with files and directories, such as pwd, ls, cd, mkdir, touch, cat, cp, mv, and rm.

Commands generally follow the format command options target. Deletion, movement, recursive options, and sudo can directly affect the system. Before running them, double-check your current location, the target path, and the intended scope. Linux servers are generally managed by typing commands into a terminal rather than using a mouse.

Typing commands on a dark screen may seem difficult at first. However, the commands used repeatedly in everyday server administration are relatively few.

Start by learning the commands needed for these tasks.

• Checking your current location

• Listing directories and files

• Changing directories

• Creating directories and files

• Copying files

• Moving files and directories

• Deleting files and directories

• Viewing file contents

• Getting command help

• Shutting down and restarting the server

This article explains basic Linux commands using an Ubuntu server.

The Terminal and Command Structure

Understanding the Linux Terminal Prompt

After logging in to a Linux server, you will see a prompt similar to this.

apple2ne1@project-dev-server:~$

Each part has the following meaning.

apple2ne1 @ project-dev-server : ~ $
Username     Server name         Current location

• apple2ne1: the currently logged-in user

• project-dev-server: the name of the server you are connected to

• ~: the current user’s home directory

• $: a session running with ordinary user privileges

When logged in as the administrator account, root, you may see # instead of $.

root@project-dev-server:~#

In general, it is safer to log in as an ordinary user and prefix only the commands that need elevated privileges with sudo, rather than working directly as root.

Basic Command Format

Linux commands generally use the following format.

command options target

Consider the following command.

ls -la /home

Each part has the following meaning.

ls      -la      /home
Command Options  Target path

• ls: lists files and directories

• -la: shows detailed information and hidden files

• /home: the directory to examine

Not every command requires options and a target.

pwd

Some commands, such as pwd, can be used on their own.

Checking Your Current Location and Paths

pwd: Check Your Current Location

Use pwd to find out which directory you are currently working in.

pwd

pwd stands for print working directory.

Output:

/home/apple2ne1

This means your current working directory is /home/apple2ne1.

Make a habit of using pwd to check your current location before copying or deleting files on a server.

Absolute and Relative Paths

Linux provides two ways to specify the location of a file or directory: absolute paths and relative paths.

Absolute Paths

An absolute path is the full path starting from the top-level directory, /.

/home/apple2ne1/projects

An absolute path always refers to the same location, regardless of your current directory.

Example:

cd /home/apple2ne1/projects

Relative Paths

A relative path describes a location starting from your current directory.

If your current directory is /home/apple2ne1, the following command moves into its projects subdirectory.

cd projects

The destination of a relative path can change depending on your current directory.

Common Path Symbols

Linux paths use several special symbols.

For example, the following command moves to the current user’s home directory.

cd ~

The following command produces the same result.

cd

To move to the parent directory, enter:

cd ..

To return to the directory you were in previously, use:

cd -

Listing Files and Directories

ls: View a Directory Listing

Use ls to see the files and subdirectories in your current directory.

ls

Example output:

Documents  Downloads  projects  notes.txt

In a terminal with color enabled, directories and files may appear in different colors.

ls -l: View Details

Use the -l option to display file permissions, ownership, size, and modification time.

ls -l

Example output:

drwxr-xr-x 2 apple2ne1 apple2ne1 4096 Jul 20 10:20 project
-rw-r--r-- 1 apple2ne1 apple2ne1  520 Jul 20 10:30 notes.txt

The main fields are as follows.

Permissions Owner      Group       Size   Modified       Name
drwxr-xr-x   apple2ne1   apple2ne1    4096   Jul 20 10:20   projects

If the first character is d, the entry is a directory.

drwxr-xr-x

If the first character is -, the entry is a regular file.

-rw-r--r--

ls -a: Show Hidden Files

Linux treats files and directories whose names start with a dot as hidden entries.

Example:

.ssh
.bashrc
.git

To include hidden entries, use:

ls -a

ls -la: Show Details and Hidden Files Together

This is one of the most frequently used forms in everyday work.

ls -la

It combines the -l and -a options.

The following two commands mean the same thing.

ls -la

ls -l -a

List a Specific Directory

You can examine another directory without changing your current location.

ls /home

To view the contents of the home directory in detail, enter:

ls -la /home/apple2ne1

Changing Directories

cd: Change Directory

Use cd to move to another directory.

cd stands for change directory.

cd project

This moves into the project subdirectory of your current directory.

After moving, check your current location.

pwd

Move to Your Home Directory

The following command moves to the current user’s home directory.

cd

Alternatively, you can enter:

cd ~

A user’s home directory is usually located at a path like this.

/home/username

Example:

/home/apple2ne1

Move to the Parent Directory

To move one level above your current directory, use:

cd ..

For example, if your current location is:

/home/apple2ne1/project

After running cd .., your location will be:

/home/apple2ne1

To move up two levels, enter:

cd ../..

Move to the Root Directory

To move to the starting point of the entire Linux directory hierarchy, use:

cd /

/ is called the root directory.

You can see the following main directories.

ls

Example output:

bin  boot  dev  etc  home  opt  root  tmp  usr  var

Return to the Previous Directory

To return to your previous working directory, use:

cd -

Example:

cd /etc
cd /var
cd -

The final command returns you to /etc.

Creating Directories

mkdir: Create a Directory

Use mkdir to create a new directory.

mkdir stands for make directory.

mkdir project

This creates a directory named project in your current location.

Check:

ls -l

Create Multiple Directories at Once

You can create several directories in one command.

mkdir images documents backup

This creates the following three directories.

images
documents
backup

mkdir -p: Create a Nested Directory Structure

Suppose you want to create a directory structure with several levels at once.

project/config/nginx

A plain mkdir command may fail if the intermediate directories do not exist.

mkdir project/config/nginx

Example error:

mkdir: cannot create directory ‘project/config/nginx’: No such file or directory

Use the -p option in this case.

mkdir -p project/config/nginx

All the required intermediate directories are created as well.

project
└── config
    └── nginx

Think of -p as creating the parent directories too.

If the directory already exists, the command normally continues without an error.

Creating Files

touch: Create an Empty File

Use touch to create an empty file.

touch notes.txt

Check:

ls -l

Example output:

-rw-r--r-- 1 apple2ne1 apple2ne1 0 Jul 20 11:10 notes.txt

A size of 0 means the file does not yet contain any data.

Create Multiple Files at Once

You can create several empty files at once as follows.

touch file1.txt file2.txt file3.txt

Another Use of touch

Running touch on an existing file updates its modification time to the current time without changing its contents.

touch notes.txt

Thus, touch is also a command for updating file timestamps, rather than simply creating files.

Viewing File Contents

cat: Display an Entire File

Use cat to display the contents of a text file all at once.

cat notes.txt

Example contents:

Linux server setup notes
SSH port: 22

This is convenient for short files.

For a very long file, the text scrolls past quickly, so another command is more suitable.

less: Read a Long File

Use less to read a long file one screen at a time.

less notes.txt

Main controls:

This is often used to read server logs and long configuration files.

Example:

less /var/log/auth.log

If elevated permissions are required, you can run it as follows.

sudo less /var/log/auth.log

head: View the Beginning of a File

Use the following command to view the first 10 lines of a file.

head notes.txt

Use the -n option to view the first 20 lines.

head -n 20 notes.txt

tail: View the End of a File

Use the following command to view the last 10 lines of a file.

tail notes.txt

Last 20 lines:

tail -n 20 notes.txt

tail -f: Follow a Log in Real Time

Use the following command to watch new content as it is added to a log file.

tail -f /var/log/auth.log

This is useful for continuously updated logs, such as SSH connection records.

To stop, press:

Ctrl + C

Editing Files

nano: A Simple Text Editor

nano is a beginner-friendly editor for modifying files in the terminal.

nano notes.txt

If the file does not exist, you can create it; if it already exists, you edit its current contents.

Shortcuts like the following appear at the bottom of the screen.

^O Write Out
^X Exit

Here, ^ represents the Ctrl key.

Save

Ctrl + O

Check the filename, then press Enter.

Exit

Ctrl + X

Save and Exit

1. Ctrl + O

1. Enter

1. Ctrl + X

If you press Ctrl + X after making changes, you may be asked whether to save them.

Save modified buffer?

• Y: save

• N: exit without saving

• Ctrl + C: cancel exiting

The screenshot below shows an empty Nano buffer and its shortcuts, with a warning that the current directory is not writable. It does not demonstrate a successful file save. If you see the same warning, exit Nano, move to your own writable home directory, and run nano notes.txt again.

Copying Files and Directories

cp: Copy a File

Use cp to copy a file.

cp stands for copy.

cp notes.txt notes-backup.txt

This copies notes.txt to a new file named notes-backup.txt.

Check:

ls -l

Copy a File to Another Directory

You can copy a file from your current location to another directory.

cp notes.txt backup/

You can also change the filename while copying it.

cp notes.txt backup/server-notes.txt

cp -r: Copy a Directory

Use the -r option to copy a directory along with its contents.

cp -r project project-backup

-r stands for recursive.

This means copying subdirectories and their files as well.

cp -i: Confirm Before Overwriting

Use the -i option to request confirmation before overwriting an existing file with the same name.

cp -i notes.txt backup/notes.txt

You may see a question like this.

cp: overwrite 'backup/notes.txt'?

Enter y to overwrite or n to cancel.

cp -a: Copy While Preserving Attributes

Use the -a option to preserve attributes such as permissions, ownership, and timestamps as far as possible.

cp -a project project-backup

This is often used for backups.

Moving Files and Directories

mv: Move a File

Use mv to move a file to another directory.

mv stands for move.

mv notes.txt documents/

This moves notes.txt from the current location into the documents directory.

mv: Rename a File

On Linux, mv also handles file renaming.

mv notes.txt server-notes.txt

This renames notes.txt to server-notes.txt.

Rename a Directory

You can rename a directory in the same way.

mv old-project new-project

Move Multiple Files into the Current Directory

When moving several files, it is safer to inspect the targets first and name them explicitly, rather than using a glob pattern to select everything in the parent directory.

ls -la ..
mv ../notes.txt ../config.yaml .

The final . means the current directory. This example moves only notes.txt and config.yaml from the parent directory into the current directory.

A broad glob selecting the parent directory’s contents can unexpectedly move sibling entries of your current directory, while excluding hidden files whose names start with a dot. Do not use it in beginner exercises.

Deleting Files and Directories

rm: Delete a File

Use rm to delete a file.

rm notes.txt

Files deleted from a Linux terminal generally do not go to a recycle bin.

Be careful: running the command deletes the file immediately.

Delete Multiple Files

You can delete several files at once.

rm file1.txt file2.txt file3.txt

rm -i: Confirm Before Deleting

Use the -i option to request confirmation before deletion.

rm -i notes.txt

Example output:

rm: remove regular file 'notes.txt'?

Enter y to delete or n to cancel.

Using rm -i is safer when you are first learning Linux.

rmdir: Delete an Empty Directory

Use rmdir to delete an empty directory.

rmdir empty-folder

The directory will not be removed if it contains files or other directories.

Example error:

rmdir: failed to remove 'project': Directory not empty

rm -r: Delete a Directory and Its Contents

Use the -r option to delete a directory and all the files inside it.

rm -r project

This command deletes the project directory and everything it contains.

To confirm each deletion, enter:

rm -ri project

rm -rf: Force Deletion

The following command forcibly deletes a directory and all its contents without asking for confirmation.

rm -rf project

Option meanings:

-r = recursively delete entries within directories
-f = ignore nonexistent files and missing operands, and never prompt

rm -rf is a very powerful and dangerous command.

In particular, never run a command like this.

sudo rm -rf /

This extremely dangerous command targets the entire system for deletion. Modern GNU rm refuses to delete / directly by default, but bypassing its protection or specifying the wrong path in a recursive deletion can still severely damage the system.

An empty path variable can also be dangerous, as in the following example.

rm -rf "$TARGET"/*

If $TARGET is empty or has an unexpected value, you could delete the wrong location.

Always check with the following commands before deleting anything.

pwd
ls -la

It is also a good idea to display the deletion target first.

ls -la project

Finding Files

find: Find Files and Directories

To find a file with a particular name beneath your current directory, enter:

find . -name "notes.txt"

Meaning of each part:

find   .   -name   "notes.txt"
Find   Here       By name  Name to find

Search Without Matching Case

Use -iname for a case-insensitive search.

find . -iname "notes.txt"

All of the following files may be found.

notes.txt
Notes.txt
NOTES.TXT

Find Only Directories

Use -type d to search only for directories.

find . -type d -name "backup"

Find Only Files

Use -type f to search only for regular files.

find . -type f -name "*.txt"

*.txt matches filenames ending in .txt.

Searching File Contents

grep: Find Text Within a File

Use grep to find a particular word or phrase in a file’s contents.

grep "SSH" notes.txt

This prints the lines in notes.txt that contain SSH.

Search Without Matching Case

grep -i "ssh" notes.txt

The search can match all of the following forms.

SSH
ssh
Ssh

Show Line Numbers

grep -n "SSH" notes.txt

Example output:

12:SSH port is 22.

12 means that the text appears on line 12 of the file.

Search Multiple Files and Subdirectories

Use the -r option to search files in the current directory and its subdirectories.

grep -r "project-dev-server" .

To search without matching case and display line numbers, enter:

grep -rin "project-dev-server" .

Checking File Sizes and Disk Space

du: Check File and Directory Space Usage

Use the following command to show the total space used by the current directory in a readable format.

du -sh .

Option meanings:

-s = show only the total
-h = display human-readable units

Example result:

1.2G    .

This means the current directory uses approximately 1.2 GB.

Check the Size of a Specific Directory

du -sh project

Use the following command to check the size of each entry in the current directory.

du -sh *

Hidden entries may be excluded.

df: Check Overall Disk Usage

Use the following command to check total disk capacity and available space.

df -h

Example result:

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2       916G   42G  828G   5% /

Main fields:

• Size: total size

• Used: space in use

• Avail: available space

• Use%: percentage used

• Mounted on: mount location

This is a useful first command when the server is running low on storage.

Checking System and User Information

whoami: Identify the Current User

This displays the username of the currently logged-in user.

whoami

Example result:

apple2ne1

id: Check User and Group Information

Use the following command to check the current user’s ID and group memberships.

id

Example output:

uid=1000(apple2ne1) gid=1000(apple2ne1) groups=1000(apple2ne1),27(sudo)

If the current user belongs to the sudo group, they can use sudo to run commands that require administrator privileges.

groups: Check Group Memberships

Use the following command for a simple list of the groups the current user belongs to.

groups

Example result:

apple2ne1 sudo

hostname: Check the Server Name

This displays the current server’s name.

hostname

Example result:

project-dev-server

Use the following command for more detailed system information.

hostnamectl

uname: Check Linux Kernel Information

Check the kernel name:

uname

Show all available information:

uname -a

Check the Ubuntu Version

Use the following command to check the Ubuntu version.

lsb_release -a

Alternatively, inspect the following file.

cat /etc/os-release

Example result:

NAME="Ubuntu"
VERSION="26.04 LTS"

Check the Date and Time

This displays the server’s current date and time.

date

Example result:

Mon Jul 20 13:30:15 PDT 2026

Use the following command to check the time zone settings as well.

timedatectl

Basic Network Commands

ip addr: Check IP Addresses

Use the following command to check the server’s network addresses.

ip addr

You can also use this shorter form.

ip a

Look for a section like this in the output.

inet 192.168.1.231/24

Here, the server’s IP address is:

192.168.1.231

127.0.0.1 is a loopback address used only within the server. It is not the address an external PC uses to connect to it.

Display Just the IP Addresses

The following command provides a simple list of the IP addresses assigned to the server.

hostname -I

Example result:

192.168.1.231

If there are multiple network interfaces, several IP addresses may appear.

ping: Check Network Connectivity

Use ping to check whether you can communicate with another device.

ping 192.168.1.240

Check Internet connectivity:

ping google.com

On Linux, ping can continue running indefinitely.

To stop, press:

Ctrl + C

To limit it to four requests, enter:

ping -c 4 google.com

ss: Check Ports in Use

Use the following command to inspect ports that are open or listening on the server.

ss -tuln

Option meanings:

• t: TCP

• u: UDP

• l: listening sockets

• n: show port numbers numerically

To check the default SSH port, 22, you can use:

ss -tuln | grep ":22"

Using Administrator Privileges

sudo: Run a Command with Administrator Privileges

An ordinary user may need administrator privileges to change system settings.

Prefix the command with sudo in that case.

sudo apt update

sudo runs a command as another user. Unless a user is specified, it normally runs the command as root.

The first time you run it, you may be asked for your current user’s password.

[sudo] password for apple2ne1:

No characters or asterisks appear on screen while you type the password.

The input is being accepted; it is simply hidden for security.

Enter the password, then press Enter.

Why You Should Not Use sudo for Every Command

sudo grants powerful privileges that can affect the entire system.

An incorrect command can cause problems such as:

• Deleting system files

• Changing permissions and ownership

• Stopping services

• Boot failures

• Loss of network connectivity

You usually do not need sudo to create or edit ordinary files in your own home directory.

For example, the following commands are best run as an ordinary user.

mkdir ~/project
touch ~/notes.txt
nano ~/notes.txt

Creating personal files with sudo can make root their owner, preventing your ordinary user account from editing them later.

Installing and Updating Software

apt update: Refresh Package Lists

Use the following command to refresh the information Ubuntu uses to install software.

sudo apt update

This updates the lists of available packages, rather than updating the installed programs themselves.

apt upgrade: Update Installed Software

Use the following command to update installed packages to their latest available versions.

sudo apt upgrade

If a confirmation prompt appears, review the proposed changes before proceeding.

You can use the -y option to answer yes automatically.

sudo apt upgrade -y

On a server, however, it is safer to review the changes before proceeding.

Install Software

For example, enter the following command to install tree.

sudo apt install tree

You may be asked to confirm the installation.

Do you want to continue? [Y/n]

Press Y or Enter to continue.

Remove Software

Use the following command to remove an installed program.

sudo apt remove tree

Use the following command to remove its configuration files as well.

sudo apt purge tree

Use the following command to remove dependencies that are no longer needed.

sudo apt autoremove

Managing Services

systemctl status: Check Service Status

Use the following command to check the SSH service status.

sudo systemctl status ssh

Key status:

active (running)

This means the service is running normally.

To leave the status display, press:

q

Start a Service

sudo systemctl start ssh

Stop a Service

sudo systemctl stop ssh

Be careful when stopping the SSH service during a remote SSH session: it can affect current or subsequent connections.

Restart a Service

After changing the configuration file, check its syntax first.

sudo sshd -t

If there are no errors, apply the configuration with the following command.

sudo systemctl restart ssh

Restarting during a remote SSH session can disconnect you, so have a separate server console or another recovery method available.

Configure Automatic Startup at Boot

The following commands apply to a configuration that runs ssh.service directly. For socket-activated configurations used since Ubuntu 22.10, also read the ssh.socket explanation that follows.

sudo systemctl enable ssh

Disable automatic startup:

sudo systemctl disable ssh

Check whether automatic startup is enabled:

sudo systemctl is-enabled ssh

disabled After Selecting OpenSSH Server During Ubuntu Installation

Since Ubuntu 22.10, and particularly on Ubuntu 24.04 LTS, ssh.service may show disabled even though you selected OpenSSH Server during installation, because SSH may be activated through ssh.socket rather than directly through ssh.service. The configuration can vary with the distribution version and changes made after installation.

Do not conclude that SSH will be unavailable after boot solely because ssh.service is disabled. Check ssh.socket and whether the actual port is listening as well.

Check with the following commands.

systemctl is-enabled ssh.socket
systemctl is-active ssh.socket

Example of a normal result:

enabled
active

In this state, ssh.socket begins listening when the computer boots and starts ssh.service when an incoming SSH connection request arrives. This is called socket activation.

To check the status in detail:

systemctl status ssh.socket
systemctl status ssh.service

Alternatively, check whether the SSH port is actually listening.

sudo ss -tlnp | grep ':22'

Example result:

LISTEN 0 4096 0.0.0.0:22

This result indicates that the server is ready to receive SSH connection requests.

The startup setting and current running state are different. In the next screenshot, check the Loaded and Active fields separately.

Stopping Commands and Clearing the Screen

Ctrl + C: Stop a Running Command

Use this to stop a command that keeps running.

Example:

ping google.com

Stop:

Ctrl + C

You can also use it to interrupt tail -f, some installation commands, and running programs.

clear: Clear the Terminal Screen

Use the following command to clear the terminal display.

clear

You can also use a keyboard shortcut.

Ctrl + L

This clears the visible display; it does not delete your command history.

history: View Previous Commands

Use the following command to view the commands you have entered.

history

Example output:

101  pwd
102  ls -la
103  cd project
104  nano notes.txt

You can also find only the commands containing a particular word.

history | grep ssh

Reuse a Previous Command

Press the up arrow key to recall a previous command.

↑

Press the down arrow key to move forward through the history.

↓

You can edit and run a recalled command without retyping it in full.

Tab: Auto-Completion

Type part of a filename or directory name, then press Tab to complete it automatically.

For example, suppose the following directory exists.

project-development

Type only the beginning of its name, as follows.

cd pro

Pressing Tab may then complete it automatically.

cd project-development

If several names match, press Tab twice to see the available options.

Auto-completion is very useful for reducing typos and entering long paths quickly.

Getting Command Help

--help: Brief Help

Most commands provide a --help option.

ls --help

cp --help

rm --help

It shows the supported options and how to use the command.

man: Command Manuals

Use man for more detailed documentation.

man ls

man stands for manual.

Main controls:

Example:

man chmod

which: Locate a Command

This checks the path where a particular command is installed.

which ssh

Example result:

/usr/bin/ssh

If the command is not installed, there may be no output.

Combining Commands

The Pipe |

Use a pipe to pass the output of one command to another.

history | grep ssh

Execution sequence:

1. history prints previous commands.

1. grep ssh displays only the lines containing ssh.

Another example:

ls -la | less

This lets you view a long file listing one screen at a time.

>: Save Output to a File

Use > to save a command’s output to a file.

ls -la > file-list.txt

The output is saved in file-list.txt instead of being displayed on screen.

If the file already exists, its contents are overwritten.

>>: Append to an Existing File

Use >> to append new output while preserving the existing contents.

date >> server-log.txt

Each time the command runs, date information is appended to the file.

&&: Run the Next Command Only If the First Succeeds

mkdir project && cd project

Execution sequence:

1. Create the project directory.

1. If creation succeeds, move into project.

You can use the following to refresh the package lists and then upgrade packages.

sudo apt update && sudo apt upgrade

If the first command fails, the second does not run.

;: Run the Next Command Regardless of Success

pwd; ls -la

Once pwd finishes, ls -la runs regardless of whether pwd succeeded.

When first learning Linux, run commands one at a time and check the results, rather than combining several commands on one line.

Shutting Down and Restarting the Server

Shut Down the Server

Use the following command to shut down a Linux server safely.

sudo shutdown now

Alternatively, use:

sudo poweroff

The SSH connection closes when the server powers off.

To use a physical server again, you may need to press its power button or use a remote power feature such as Wake-on-LAN (WOL).

Shut Down After a Delay

Shut down in 10 minutes:

sudo shutdown +10

Cancel the scheduled shutdown:

sudo shutdown -c

Restart the Server

Use the following command to restart the server.

sudo reboot

Your SSH connection closes when the restart begins.

Wait for the server to start again, then reconnect.

After changing network or SSH settings, check that the configuration is correct before restarting immediately.

Quick Reference for Common Commands

Essential Precautions for Beginners

Check Your Current Location Before Deleting

pwd
ls -la

Always check your current location and deletion targets, especially before using rm, rm -r, or rm -rf.

Quote Paths That Contain Spaces

Suppose a directory has the following name.

My Project

Enclose a path containing spaces in quotes.

cd "My Project"

Alternatively, put a backslash before the space.

cd My\ Project

This is necessary because the shell uses spaces to separate command arguments.

Pay Attention to Letter Case

Linux distinguishes uppercase and lowercase letters in filenames and command names.

The following names refer to different files.

notes.txt
Notes.txt
NOTES.txt

These commands are also different.

ls
LS

ls is a valid command, whereas LS usually does not exist.

Spell Commands Correctly

The following command is correct.

mkdir project

The following command is incorrect.

mkidr project

Example error:

mkidr: command not found

If you see command not found, check the command’s spelling first.

Avoid Unnecessary sudo for Personal Files

You usually do not need sudo to create files or directories in your home directory.

mkdir ~/project
touch ~/project/notes.txt

Using sudo unnecessarily can make root the owner of a file, preventing an ordinary user from editing it.

Check the Result After Each Command

Make a habit of running one command at a time and checking its result, rather than executing many commands at once.

Example:

mkdir project

Check:

ls -ld project

Move:

cd project

Check the current location:

pwd

This approach reduces mistakes and helps you understand how Linux commands work.

Basic Practice

Follow this exercise in order to learn the main basic commands.

Step 1: Move to Your Home Directory

cd

Check the current location:

pwd

Step 2: Create a Practice Directory

mkdir linux-practice

Check:

ls -l

Step 3: Enter the Practice Directory

cd linux-practice

Check the current location:

pwd

Step 4: Create Subdirectories

mkdir documents backup

Check:

ls -l

Step 5: Create a File

touch notes.txt

Step 6: Edit the File

nano notes.txt

Enter the following text.

Linux command practice
Server name: project-dev-server

Save:

Ctrl + O
Enter

Exit:

Ctrl + X

Step 7: View the File Contents

cat notes.txt

Step 8: Copy the File

cp notes.txt backup/notes-backup.txt

Check:

ls -l backup

Step 9: Move the File

mv notes.txt documents/

Check:

ls -l documents

Step 10: Rename the File

mv documents/notes.txt documents/linux-notes.txt

Step 11: Check the Entire Structure

If tree is installed, you can use:

tree

Expected result:

.
├── backup
│   └── notes-backup.txt
└── documents
    └── linux-notes.txt

If tree is not installed, install it with:

sudo apt install tree

Step 12: Delete the Practice Directory

First, move to your home directory.

cd

Check the directory you intend to delete.

ls -la linux-practice

Delete it with confirmation prompts.

rm -ri linux-practice

Key Takeaways

You do not need to memorize every command at once when learning Linux basics.

Start by using the following commands repeatedly.

pwd
ls -la
cd
mkdir
touch
nano
cat
cp
mv
rm

Check your current location before working on the server.

pwd

Check the files and directories.

ls -la

Before running a deletion or movement command, double-check the target path.

ls -la target-path

Linux commands are short, but they directly affect the system. Running one command and checking its result makes server administration much safer.

Precautions and Limitations

• Overwrite and deletion behavior in rm, mv, and cp can vary with options, aliases, and the distribution environment. Use --help or man to check your current environment.
• rm -rf recursively removes files and directories without confirmation. Do not use it as a routine fix in learning exercises.
• Use sudo only when needed, and check the target path and the command’s effects before running it.
• apt upgrade and service restarts can affect running services. Review the proposed changes and maintenance window first.
• A missing ping reply does not necessarily mean the network connection is down. A firewall or the target device may block ICMP replies.
• This article introduces basic commands. It does not replace comprehensive coverage of shell expansion, permissions, processes, log analysis, or network diagnostics.

References and Sources

• GNU Coreutils Manual — basic commands for files, directories, file contents, and storage — 2026-08-02
• Ubuntu Manpages — Ubuntu package, network, and system commands, including apt — 2026-08-02
• Ubuntu 24.04 LTS @@INLINE_0@@ Manpage — rm -f, recursive deletion, and --preserve-root behavior — 2026-08-02
• Ubuntu 24.04 LTS Release Notes — scope of OpenSSH systemd socket activation — 2026-08-02
• systemd @@INLINE_0@@ — checking, starting, stopping, and restarting services — 2026-08-02