In this Linux tutorial post, we are writing on all Linux basic commands with examples which every Linux beginner should know. It will help you to kickstart on any Linux Operating System.

We expect, you have already installed the Linux Operating System in your system and we are ready to start the command in terminal.

We are trying to keep this post simple and easy to use for all Linux Beginners. So all the examples are taken as reference from the daily and commonly use command. We will be showing only some arguments in commands which are commonly use and very helpful. Knowing about the command’s argument is good but all arguments are mostly not in regular use. With the experience you will naturally learn some more arguments with commands.

Table of Contents

1. Know Autocompletion Of Command On Terminal
2. How to take help on command in terminal itself
3. pwd
4. clear
5. whoami
6. id
7. ls
8. cd
9. mkdir
10. cat
11. rm
12. cp
13. mv
14. less
15. more
16. touch
17. date
18. history
19. top
20. ps
21. kill
22. pidof
23. echo
24. which
25. i/o redirection
26. Some More Learning On Linux Commands
27. FAQ

Know Autocompletion Of Command On Terminal

Press tab key for autocompletion of the command on terminal. Linux has this awesome feature which will reduce your time on typing the command . Let’s say an example, write half command ‘mkd’ then press Tab key in your keyboard. It should autocomplete the command. Have you also tried ? What did you get ?

How to take help on command in terminal itself

Linux beginners mostly get confused with commands when they see some experts using arguments with command. To solve this problem, we generally use two commands for taking help in terminal itself.

1. By using man command : To keep the things simple, use the man command followed with command name. For example. man ls . (Know more about man pages in our two helpful articles, “Search keyword in all available man pages – man command“, “search keyword in man page like we search in vi / vim editor“)
2. By using --help with each command: Use –help with commands , it will show you the help section in terminal as an output. For eg. ls --help

In this article, we have included both Internal and External Commands.

pwd

pwd command is for printing the name of the current working directory. Means, it shows the directory path where the current login user is working.

In given below example, it shows that the user ‘sharadchhetri’ working directory is /var/log .

We have written about pwd command in detail, the topic called “print working directory ( pwd , PWD , OLDPWD ) in Linux / Unix“

sharadchhetri@server01:/var/log$ pwd
/var/log
sharadchhetri@server01:/var/log$

clear

The clear command is for clearing the output in terminal.

We have already written about clear command in our article called “Linux : clear command and its keyboard shortcut“

# Example: Try like this and hit enter after clear command
sharadchhetri@server01:~$ ls
mydir  myfile  newdir  test.txt
sharadchhetri@server01:~$ clear

whoami

The whoami command will show user id which login to terminal. To be very precise, it print the user name associated with the current effective user ID.

In given below example, you can see that user called ‘sharadchhetri’ is the user id which is currently working on the terminal.

If you login and use the same command, it will show your user id on terminal. Isn’t great way to check , which user you are login to machine !?

sharadchhetri@server01:/var/log$ whoami
sharadchhetri
sharadchhetri@server01:/var/log$

You can learn more about whoami command in details – here is our post called Linux / Unix : whoami command use and advantage.

id

The id command shows the user id information. It print user and group information for each specified USER.

Lets take a look in the example.

Example 1: The output has information of user called ‘user1’. We can see its uid(user id), gid(group id)and groups name(also showing each group id) where the user1 is associated with.

Example 2: Here, we have only use the id command with current user login. It shows the current user information about its uid(user id), gid(group id) and group name with gid.

# Example 1
sharadchhetri@server01:~$ id user1
uid=1000(user1) gid=1000(user1) groups=1000(user1),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),110(lxd)
sharadchhetri@server01:~$

# Example 2
sharadchhetri@server01:~$ id
uid=1001(sharadchhetri) gid=1001(sharadchhetri) groups=1001(sharadchhetri)
sharadchhetri@server01:~$

ls

ls command output shows the list of files and directories. If you define the location then it will show the list of files/directories of that location.

We have given some examples of ls command here. You can also combine the arguments with the command.

-l = use a long listing format. Shows some good details.

-a = shows hidden files and folders.

-d = list only directories not their contents inside.

-i = shows inode numbers (or index number) of files .

# Example 1: List the files with details
sharadchhetri@server01:/home$ ls -l
total 8
drwxr-xr-x 2 sharadchhetri sharadchhetri 4096 Mar 17 13:57 sharadchhetri
drwxr-x--- 5 user1         user1         4096 Mar 13 11:29 user1
sharadchhetri@server01:/home$

# Example 2: list inside the directory
sharadchhetri@server01:/home$ ls -l /var/log/
total 3156
-rw-r--r--  1 root    root              21535 Mar 13 10:51 alternatives.log
-rw-r-----  1 root    adm                2306 Feb 15 03:46 apport.log
drwxr-xr-x  2 root    root               4096 Mar 13 10:50 apt
-rw-r--r--  1 root    root              64549 Aug  9  2022 bootstrap.log
-rw-rw----  1 root    utmp                768 Mar  5 16:43 btmp
-rw-r-----  1 root    adm              101517 Mar 17 13:49 cloud-init-output.log
-rw-r--r--  1 root    adm             2371570 Mar 17 13:49 cloud-init.log
drwxr-xr-x  2 root    root               4096 Aug  3  2022 dist-upgrade
-rw-r--r--  1 root    root             508766 Mar 13 10:51 dpkg.log
-rw-r--r--  1 root    root              32064 Mar 17 13:56 faillog
-rw-r--r--  1 root    root                485 Mar  6 17:15 fontconfig.log
drwxr-x---  3 root    adm                4096 Feb 11 14:48 installer
drwxr-xr-x  2 jenkins jenkins            4096 Feb  8 13:25 jenkins
drwxr-sr-x+ 3 root    systemd-journal    4096 Feb 11 14:49 journal
-rw-rw-r--  1 root    utmp             292584 Mar 17 13:56 lastlog
drwxr-s---  2 mysql   adm                4096 Mar  7 11:01 mysql
drwxr-xr-x  2 root    root               4096 Mar  7 17:11 nginx
-rw-------  1 root    root               5294 Mar 17 13:48 php8.1-fpm.log
drwx------  2 root    root               4096 Aug  9  2022 private
drwxr-x---  2 root    adm                4096 Feb 11 14:49 unattended-upgrades
-rw-rw-r--  1 root    utmp              65280 Mar 17 13:51 wtmp
sharadchhetri@server01:/home$

# Example 3: list hidden files with -a argument.
sharadchhetri@server01:~$ ls -l
total 0
sharadchhetri@server01:~$
sharadchhetri@server01:~$ ls -la
total 12
drwxr-xr-x 3 sharadchhetri sharadchhetri 4096 Mar 17 16:11 .
drwxr-xr-x 4 root          root          4096 Mar 17 13:57 ..
drwxrwxr-x 2 sharadchhetri sharadchhetri 4096 Mar 17 16:11 .myfolder
-rw-rw-r-- 1 sharadchhetri sharadchhetri    0 Mar 17 16:11 .test
sharadchhetri@server01:~$

# Example 4: List only directory, not its content inside.
sharadchhetri@server01:~$ ls -ld /var
drwxr-xr-x 14 root root 4096 Mar  7 11:15 /var
sharadchhetri@server01:~$

# Example 5: List index numbers of files.

sharadchhetri@server01:/tmp$ ls -i
136737 hsperfdata_jenkins                                136743 systemd-private-df8285a24ce94843975ca1d17763939c-systemd-logind.service-2gQ93X       4685 winstone1040274427452123975.jar
136745 jetty-0_0_0_0-8080-war-_-any-7600975038121345778  136732 systemd-private-df8285a24ce94843975ca1d17763939c-systemd-resolved.service-3ygtJ1
136725 snap-private-tmp                                  136734 systemd-private-df8285a24ce94843975ca1d17763939c-systemd-timesyncd.service-uFF7J0
sharadchhetri@server01:/tmp$

cd

The cd command means change the current directory directory. As a user , we need to switch or change to directories for work. For example, I want to go to /home directory and then late wants to go to /etc directory. Here the cd command will help.

cd ~ : Changing to current USER Default Home Directory

cd - : Changing back to previous directory.

cd .. : Changing back to One level back

We have written a article on cd command with example, the post is called “6 important examples of cd command on Linux and Unix Systems” . This post is comprehensive guide on cd command.

# Example 1: Changing directory by using the path.
sharadchhetri@server01:/tmp$ pwd
/tmp
sharadchhetri@server01:/tmp$ cd /home
sharadchhetri@server01:/home$
sharadchhetri@server01:/home$ pwd
/home
sharadchhetri@server01:/home$ cd /etc
sharadchhetri@server01:/etc$ pwd
/etc

#Example 2: Changing Directory to USER default Home directory
sharadchhetri@server01:/etc$ cd ~
sharadchhetri@server01:~$ pwd
/home/sharadchhetri
sharadchhetri@server01:~$

# Example 3: Changing back to previous directory. Using hyphen with cd
sharadchhetri@server01:~$ cd -
/etc
sharadchhetri@server01:/etc$
sharadchhetri@server01:/etc$ pwd
/etc
sharadchhetri@server01:/etc$

# Example 4: Changing back to one level directory. 
sharadchhetri@server01:/etc$ cd ..
sharadchhetri@server01:/$ pwd
/
sharadchhetri@server01:/$


# Example 5: Similar to Example 4 ,only Changing directory to two level.

sharadchhetri@server01:/var/www/html$ pwd
/var/www/html
sharadchhetri@server01:/var/www/html$ cd ../..
sharadchhetri@server01:/var$ pwd
/var
sharadchhetri@server01:/var$

mkdir

The mkdir command is for creating directory.

-p : when using this argument, it create parent directory when needed. See the Example 3.

# Example 1: Create Directory in current path.
sharadchhetri@server01:~$ mkdir test
sharadchhetri@server01:~$ ls -ld test
drwxrwxr-x 2 sharadchhetri sharadchhetri 4096 Mar 17 16:37 test
sharadchhetri@server01:~$

#Example 2: Create Directory in custom path
sharadchhetri@server01:~$ mkdir /tmp/mytest
drwxrwxr-x 2 sharadchhetri sharadchhetri 4096 Mar 17 16:38 /tmp/mytest/
sharadchhetri@server01:~$

# Example 3: Create parent directories as needed.
sharadchhetri@server01:~$ ls -l test
total 0
sharadchhetri@server01:~$
sharadchhetri@server01:~$ mkdir -p test/new/another/mydir

sharadchhetri@server01:~$ ls -ld test/new/another/mydir/
drwxrwxr-x 2 sharadchhetri sharadchhetri 4096 Mar 17 16:41 test/new/another/mydir/
sharadchhetri@server01:~$

cat

The cat command is for concatenating the file contents. Mostly this is use for reading the small size file also. Explore its arguments by yourself, some interesting things you will find.

# Example 1
sharadchhetri@server01:~$ cat test.txt
This is a test file
For showing cat command
sharadchhetri@server01:~$

# Example 2: Concatenating the two files
sharadchhetri@server01:~$ cat test.txt
This is a test file
For showing cat command
sharadchhetri@server01:~$ cat color
This is color file
red blue green
sharadchhetri@server01:~$ cat color test.txt
This is color file
red blue green
This is a test file
For showing cat command
sharadchhetri@server01:~$

rm

The rm command is for removing files and directories.

-d = Remove empty directory

-f = Remove forcefully

-r = Remove recursively.

-i : Prompt before removing

# Example 1: Removed empty directory.
sharadchhetri@server01:~$ ls -l newtest/
total 0
sharadchhetri@server01:~$ rm -d newtest/
sharadchhetri@server01:~$ ls -ld newtest
ls: cannot access 'newtest': No such file or directory
sharadchhetri@server01:~$

# Example 2: Remove recursive dir
sharadchhetri@server01:~$ rm -r test/new/another/mydir/
sharadchhetri@server01:~$ ls -l test
test/     test.txt
sharadchhetri@server01:~$ ls -l test/new/another/
total 0
sharadchhetri@server01:~$

# Example 3: Forcefully and recursively remove the dir
sharadchhetri@server01:~$ rm -fr test/new/another/
sharadchhetri@server01:~$ ls -l test/new/
total 0
sharadchhetri@server01:~$

# Example 4: Remove file.
sharadchhetri@server01:~$ ls -l
total 12
-rw-rw-r-- 1 sharadchhetri sharadchhetri   34 Mar 17 16:47 color
drwxrwxr-x 3 sharadchhetri sharadchhetri 4096 Mar 17 16:41 test
-rw-rw-r-- 1 sharadchhetri sharadchhetri   44 Mar 17 16:46 test.txt
sharadchhetri@server01:~$ rm color
sharadchhetri@server01:~$ ls -l
total 8
drwxrwxr-x 3 sharadchhetri sharadchhetri 4096 Mar 17 16:41 test
-rw-rw-r-- 1 sharadchhetri sharadchhetri   44 Mar 17 16:46 test.txt
sharadchhetri@server01:~$

cp

The cp command is for copying files and folders.

-r = Recursive for directories.

-f = Forcefully

# Example 1: Copying file
sharadchhetri@server01:~$ ls -l
total 8
drwxrwxr-x 3 sharadchhetri sharadchhetri 4096 Mar 17 16:41 mydir
-rw-rw-r-- 1 sharadchhetri sharadchhetri   44 Mar 17 16:46 test.txt
sharadchhetri@server01:~$ cp test.txt myfile
sharadchhetri@server01:~$ ls -l
total 12
drwxrwxr-x 3 sharadchhetri sharadchhetri 4096 Mar 17 16:41 mydir
-rw-rw-r-- 1 sharadchhetri sharadchhetri   44 Mar 17 17:01 myfile
-rw-rw-r-- 1 sharadchhetri sharadchhetri   44 Mar 17 16:46 test.txt
sharadchhetri@server01:~$

# Example 2: Copying directory by using -r argument. See intentional error.
sharadchhetri@server01:~$ ls -ld mydir/
drwxrwxr-x 3 sharadchhetri sharadchhetri 4096 Mar 17 16:41 mydir/
sharadchhetri@server01:~$ cp mydir newdir
cp: -r not specified; omitting directory 'mydir'
sharadchhetri@server01:~$
sharadchhetri@server01:~$ cp -r mydir/ newdir
sharadchhetri@server01:~$ ls -l
total 16
drwxrwxr-x 3 sharadchhetri sharadchhetri 4096 Mar 17 16:41 mydir
-rw-rw-r-- 1 sharadchhetri sharadchhetri   44 Mar 17 17:01 myfile
drwxrwxr-x 3 sharadchhetri sharadchhetri 4096 Mar 17 17:03 newdir
-rw-rw-r-- 1 sharadchhetri sharadchhetri   44 Mar 17 16:46 test.txt
sharadchhetri@server01:~$

mv

The mv command can be used for two purposes.

1. To move the file or directory
2. To rename the file or directory

We have written about mv command in this Article called “How To Rename And Move The Directory And Files In Linux“

Syntax

mv [arguments] SOURCE DESTINATION

Example 1: Here in this example, we are moving Directory called newtest to Desktop

mv newtest/ /home/linux/Desktop/

Example 2: In this example, we are renaming newtest Directory and also moving it to /home/linux directory

mv newtest/ /home/linux/sharadtest

less

The less command is for viewing file contents. It is recommended to use less command if you want to view big size file. The readable width get adjusted automatically.

# Example: Give filename and use cursor for navigation. Press 'q' to exit.
less filename

more

The more command is also similar to less command. Use for viewing the file. The difference can be seen in File Output when sometime you will notice the content is wide and out of screen.

want to view big size file. The readable width get adjusted automatically.

# Example: Give filename and use cursor for navigation. Press 'q' to exit.
more filename 

touch

The touch command update the access and modification times of each FILE to the current time . You can modify the access and modification time on file and directory both. But by using this command we can also create empty file.

# Example: Creating empty file
sharadchhetri@server01:~$ touch /tmp/myfile
sharadchhetri@server01:~$ ls -l /tmp/myfile
-rw-rw-r-- 1 sharadchhetri sharadchhetri 0 Mar 17 17:21 /tmp/myfile
sharadchhetri@server01:~$

# Example 2: See the access and modification time of file.
sharadchhetri@server01:~$ touch -d '8 July 2022 11:02' testfile

sharadchhetri@server01:~$ stat testfile
  File: testfile
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 427460      Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/sharadchhetri)   Gid: ( 1001/sharadchhetri)
Access: 2022-07-08 11:02:00.000000000 +0000
Modify: 2022-07-08 11:02:00.000000000 +0000
Change: 2023-03-17 17:23:52.337607682 +0000
 Birth: 2023-03-17 17:23:52.337607682 +0000
sharadchhetri@server01:~$

date

The date command shows date as well as we can set date in the system. It is one of the useful command which every system admin needs. One of the important use case is , this command is heavily use in Backup Scripts or while taking backup for marking as a backup date of source.

user1@server01:~$ date
Sat Mar 18 10:55:16 UTC 2023
user1@server01:~$

You can learn more on Date command from our this article – “Learn Linux Date Command With Examples“

history

The name of command itself speaks its use. This is for showing history of the commands which user has run on the terminal. To use this command simply run –

history

top

The top command is for displaying the process and other various useful information like Date, System Uptime, Load Average, CPU, Memory etc.

Type the command and hit enter.

top

ps

The ps displays information about a selection of the active processes but not in a repetitive manner just like top command do.

Example 1: Without argument when we run ps command , it shows the process of current login shell.

user1@server01:~$ ps
    PID TTY          TIME CMD
   2258 pts/0    00:00:00 bash
   3051 pts/0    00:00:00 ps
user1@server01:~$

Example 2: To display process full format listing

ps -ef

Example 3: Show all process owned by you

ps -x

kill

The kill command is for sending SIGNAL to the process. The default signal is SIGTERM means signal for terminating the process.

The kill command syntax is given below

kill [SIGNAL] [Process id]

Example: Terminate the process by using its pid (process id). We are showing the example which is often use that is kill -9 [process id]

Here in this example, we have terminated the top command process which was running in background.

user1@server01:~$ ps -x
    PID TTY      STAT   TIME COMMAND
   2231 ?        Ss     0:00 /lib/systemd/systemd --user
   2233 ?        S      0:00 (sd-pam)
   2257 ?        S      0:00 sshd: user1@pts/0
   2258 pts/0    Ss     0:00 -bash
   3358 pts/0    T      0:00 top
   3359 pts/0    R+     0:00 ps -x
user1@server01:~$ kill -9 3358
user1@server01:~$
[1]+  Killed                  top
user1@server01:~$ ps -x
    PID TTY      STAT   TIME COMMAND
   2231 ?        Ss     0:00 /lib/systemd/systemd --user
   2233 ?        S      0:00 (sd-pam)
   2257 ?        S      0:00 sshd: user1@pts/0
   2258 pts/0    Ss     0:00 -bash
   3368 pts/0    R+     0:00 ps -x
user1@server01:~$

pidof

The pidof command will help to display the pid or process id of the process/application.

The Syntax is as follows.

pidoff [Process Name /Application Name]

In this example, we will see the process id of the sshd.

user1@server01:~$ pidof sshd
2257 2224 661
user1@server01:~$

echo

The echo command shows the output as string when arguments are used along with it. Here is the example, it will display its own argument.

The echo command is widely used in the bash scripting also. It has various use cases.

user1@server01:~$ echo "Welcome in sharadchhetri.com"
Welcome in sharadchhetri.com
user1@server01:~$

which

The which command display the absolute path of the command . The more details we have written in this post – “How to find absolute path of command on Linux / Unix : which command”

In given below example, we have used the which command to find the absolute path of ls command.

user1@server01:~$ which ls
/usr/bin/ls
user1@server01:~$

i/o redirection

The abbreviation of i/o is Input Output. In Linux/Unix Operating System we can do the i/o redirection. To understand in simple manner the command output can be saved in some file. As this post was meant for beginner so we kept the definition simple. (If you want to know more, sharing just some clues, it has 3 streams – STDIN, STDOUT, STDERR)

Here is the one of the example.

echo Write Something In File > file.txt

There are so many commands in Linux which gives a powerful control and excitement to use. We tried to give some overview of some commands in this post. We hope this will give you a quick kickstart on your Linux terminal. Happy Linuxing .

Some More Learning On Linux Commands

In this article we tried to provide some overview and brief explanation on Linux Commands so that it eases your first step of Linux Learning.

We generally keep all the articles here on Linux Command section . You can visit to this section and read and learn from our 70+ Articles written only on Linux Command.

FAQ

In this section, we have taken some Frequently Asked Questions.