28 MOST FREQUENTLY USED BASIC LINUX COMMANDS WITH EXAMPLES

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28 MOST FREQUENTLY USED BASIC LINUX COMMANDS WITH EXAMPLES

28 MOST FREQUENTLY USED BASIC LINUX COMMANDS WITH EXAMPLES

Introduction
In this article we are going to discuss on some most frequently used basic Linux commands with examples. This article is mainly useful for beginners who just started to learn Linux or want to learn Linux. In this topic we have included all those basic Linux commands by which you can easily operate Linux operating system easily from terminal.

So let’s have a look at basic Linux commands with examples
1. List Files & Directories using ls
## ls basic Linux commands with examples
To list files and directories in Linux we can use ls command. Refer the command below.

elinuxbook@ubuntu:~$ ls
app Desktop Documents Downloads file.txt Music Pictures Public Templates Videos

List files & Directories with some important details like Permissions, Owner, Symlink & Hardlink details, Created Date, File & Directories name.

elinuxbook@ubuntu:~$ ls -l
total 36
drwxrwxr-x 3 elinuxbook elinuxbook 4096 Aug 20 2017 app
drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Desktop
drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Documents
drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Downloads
-rw-rwxrwx 1 elinuxbook elinuxbook 0 Feb 20 09:40 file.txt
drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Music
drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Pictures

List Hidden files & directories.

elinuxbook@ubuntu:~$ ls -a
. .bash_history .cache Desktop Downloads .gnupg .lesshst Music .profile .sudo_as_admin_successful .Xauthority
.. .bash_logout .compiz .dmrc file.txt .HipChat .local Pictures Public Templates .xsession-errors
app .bashrc .config Documents .gconf .ICEauthority .mozilla .pki .QtWebEngineProcess Videos .xsession-er




List files & directories with it’s Inode number.

elinuxbook@ubuntu:~$ ls -li
total 36
284379 drwxrwxr-x 3 elinuxbook elinuxbook 4096 Aug 20 2017 app
278746 drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Desktop
278760 drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Documents
278757 drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Downloads
134040 -rw-rwxrwx 1 elinuxbook elinuxbook 0 Feb 20 09:40 file.txt
278761 drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Music
278762 drwxr-xr-x 2 elinuxbook elinuxbook 4096 Aug 20 2017 Pictures

## Basic Linux commands with examples to Manage Files & Directories
2. Create a Directory in Linux
Create a new directory in Linux using mkdir command.
elinuxbook@ubuntu:~$ mkdir data

3. Delete a Directory
Delete a directory using rmdir command.

elinuxbook@ubuntu:~$ rmdir data

4. Remove/Delete a file
Delete a file using rm command.
elinuxbook@ubuntu:~$ rm file.txt

To delete a directory with content we have to use rm command with argument -rf to delete it forcefully.
elinuxbook@ubuntu:~$ rm -rf data

## Basic Linux commands with examples to Manage Users

5. Create a New user in Linux
To create a new user in Linux you can use useradd command. Refer the command below.
elinuxbook@ubuntu:~$ sudo useradd helpdesk

Also Read :

6. Set Password for a User
Set password for a user using passwd command.

elinuxbook@ubuntu:~$ sudo passwd helpdesk
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully

7. Delete a User
Delete a user using userdel command.
elinuxbook@ubuntu:~$ sudo userdel helpdesk

8. Change Permission in Linux
To change permission of files & directories in Linux you can use chmod command. Here I have shown some examples.
Allow Full access (i.e. Read, Write, Execute) to Owner/User for a file file.txt.

elinuxbook@ubuntu:~$ chmod u+rwx file.txt

Remove Write & Execute permission from Owner/User.
elinuxbook@ubuntu:~$ chmod u-wx file.txt

Allow Read, Write, Execute permission to everyone.
elinuxbook@ubuntu:~$ chmod a+rwx file.txt

You can also Allow Read, Write, Execute permission to everyone in Numerical method.

elinuxbook@ubuntu:~$ chmod 777 file.txt

9. Change Ownership of Files & Directories
You can change ownership of files & directories in Linux using chown command. The Syntax to change ownership is :
chown username:groupname filename
Change ownership of a file file.txt.

elinuxbook@ubuntu:~$ sudo chown elinuxbook:helpdesk file.txt

elinuxbook@ubuntu:~$ ls -l file.txt
-rw-rw-r– 1 elinuxbook helpdesk 0 Feb 21 07:52 file.txt

Change Group Ownership of a file using chown command.
elinuxbook@ubuntu:~$ sudo chown :elinuxbook file.txt

elinuxbook@ubuntu:~$ ls -l file.txt
-rw-rw-r– 1 elinuxbook elinuxbook 0 Feb 21 07:52 file.txt

## Basic Linux commands with examples for Backup
10. Backup data using Tar
Create a archive in Linux using Tar command.

elinuxbook@ubuntu:~$ tar -cvf file.tar file.txt

Create a Tar archive with gzip compression.
elinuxbook@ubuntu:~$ tar -czvf file.tar.gz file.txt

Extract a gzip compressed Tar archive.
elinuxbook@ubuntu:~$ tar -xzvf file.tar.gz

## Basic Linux commands with examples to compress files & directories

11. Compress Files & Directories using gzip command
Compress a file using gzip command.
elinuxbook@ubuntu:~$ gzip file.txt

Extract a gzip (.gz) compressed file.
elinuxbook@ubuntu:~$ gzip -d file.txt.gz

OR you can also use gunzip command to extract gzip compressed file.

elinuxbook@ubuntu:~$ gunzip file.txt.gz

## Basic Linux commands with examples to Shutdown the System.
12. Shutdown Linux Operating System
To immediately shutdown a linux system you can use  below command.
elinuxbook@ubuntu:~$ shutdown -h now

Shutdown a system after 10 minute.

elinuxbook@ubuntu:~$ shutdown -h +10

Cancel a scheduled Shutdown using shutdown command with argument -c.
elinuxbook@ubuntu:~$ shutdown -c

Reboot the system after 10 minute using shutdown command with argument -r.
elinuxbook@ubuntu:~$ shutdown -r +10

13. Compress files & directories using bzip2 compression
Compress a file using bzip2 command.

elinuxbook@ubuntu:~$ bzip2 test.txt

Extract a bzip2 compressed file (i.e. bz2) using bzip2 command with argument -d.
elinuxbook@ubuntu:~$ bzip2 -d test.txt.bz2

14. Copy files in Linux
You can copy files & directories in Linux using cp command. Here I am copying a file named file.txt in to a directory named data. Refer the command below.
Syntax : cp Source Destination

elinuxbook@ubuntu:~$ cp file.txt data/

15. Move/Rename file in Linux
Move OR Rename file in Linux using mv command.
Syntax : mv Source Filename Destination Filename
elinuxbook@ubuntu:~$ mv file.txt data/myfile.txt

16. Change Directory in Linux
Use cd command to Change Directory in Linux. Refer the command below.

elinuxbook@ubuntu:~$ cd data/

17. Check Current Working Directory
To check current working directory in Linux you can use pwd command. The full form of pwd is Print Working Directory. As you can see below my current working directory is “/home/elinuxbook“.
elinuxbook@ubuntu:~$ pwd
/home/elinuxbook

18. Create a New file
To create a new file in Linux you can use touch command.
elinuxbook@ubuntu:~$ touch file.txt

## ## Basic Linux commands with examples to check Process Status in Linux

19. Check Process Status in Linux
To check process status in Linux you can use ps command.
elinuxbook@ubuntu:~$ ps
PID TTY TIME CMD
2936 pts/4 00:00:03 bash
11022 pts/4 00:00:00 ps

ps command with argument -ef will show you Process Status in More details like User ID, Process ID, CPU utilization, Memory Utilization, Terminal Details and so on.
elinuxbook@ubuntu:~$ ps -ef | less

20. List connected Disks/Medias
You can List all connected Hardisks, Pen Drives and many more using fdisk command with argument -l. Refer the command below.

elinuxbook@ubuntu:~$ sudo fdisk -l
Disk /dev/sda: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xa5466322

Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 37750783 37748736 18G 83 Linux
/dev/sda2 37752830 41940991 4188162 2G 5 Extended
/dev/sda5 37752832 41940991 4188160 2G 82 Linux swap / Solaris

## Basic Linux commands with examples to check Mounted Devices in Linux
21. List Mounted Devices in Linux
You can list all mounted devices in Human Readable format using df command with argument -h.
elinuxbook@ubuntu:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 966M 0 966M 0% /dev
tmpfs 199M 14M 185M 7% /run
/dev/sda1 18G 4.9G 12G 30% /
tmpfs 992M 212K 992M 1% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 992M 0 992M 0% /sys/fs/cgroup
tmpfs 199M 64K 199M 1% /run/user/1000

Only df command will list mounted devices in Blocks.

elinuxbook@ubuntu:~$ df
Filesystem 1K-blocks Used Available Use% Mounted on
udev 988812 0 988812 0% /dev
tmpfs 203012 14032 188980 7% /run
/dev/sda1 18447100 5124524 12362476 30% /
tmpfs 1015056 212 1014844 1% /dev/shm
tmpfs 5120 4 5116 1% /run/lock
tmpfs 1015056 0 1015056 0% /sys/fs/cgroup
tmpfs 203012 64 202948 1% /run/user/1000

List mounted Devices with it’s Inode Numbers.
elinuxbook@ubuntu:~$ df -ih
Filesystem Inodes IUsed IFree IUse% Mounted on
udev 242K 459 241K 1% /dev
tmpfs 248K 683 248K 1% /run
/dev/sda1 1.2M 228K 925K 20% /
tmpfs 248K 9 248K 1% /dev/shm
tmpfs 248K 6 248K 1% /run/lock
tmpfs 248K 17 248K 1% /sys/fs/cgroup
tmpfs 248K 31 248K 1% /run/user/1000

## Basic Linux commands with examples to check Network Configurations
22. Check IP Address in Linux
To check IP Address in Linux you can use ifconfig command.

elinuxbook@ubuntu:~$ ifconfig
ens33 Link encap:Ethernet HWaddr 00:0c:29:ff:cd:2e
inet6 addr: 2405:204:f196:72e6:f609:9c3f:ccb7:8841/64 Scope:Global
inet6 addr: 2405:204:f211:47d8:3f17:e549:58e6:254b/64 Scope:Global
inet6 addr: 2405:204:f196:72e6:69be:db2b:9c8a:6051/64 Scope:Global
inet6 addr: 2405:204:f211:47d8:69be:db2b:9c8a:6051/64 Scope:Global
inet6 addr: 2405:204:f109:105f:a531:82b3:8d4a:c712/64 Scope:Global
inet6 addr: 2405:204:f109:105f:69be:db2b:9c8a:6051/64 Scope:Global
inet6 addr: fe80::b396:d285:b5b3:81c3/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8909 errors:0 dropped:0 overruns:0 frame:0
TX packets:8903 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9662594 (9.6 MB) TX bytes:1080952 (1.0 MB)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:61437 errors:0 dropped:0 overruns:0 frame:0
TX packets:61437 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4568449 (4.5 MB) TX bytes:4568449 (4.5 MB)

Use the below command to check IP Address of a particular Interface. Here I am checking IP Address of the Interface ens33.
elinuxbook@ubuntu:~$ ifconfig ens33
ens33 Link encap:Ethernet HWaddr 00:0c:29:ff:cd:2e
inet6 addr: 2405:204:f196:72e6:f609:9c3f:ccb7:8841/64 Scope:Global
inet6 addr: 2405:204:f211:47d8:3f17:e549:58e6:254b/64 Scope:Global
inet6 addr: 2405:204:f196:72e6:69be:db2b:9c8a:6051/64 Scope:Global
inet6 addr: 2405:204:f211:47d8:69be:db2b:9c8a:6051/64 Scope:Global
inet6 addr: 2405:204:f109:105f:a531:82b3:8d4a:c712/64 Scope:Global
inet6 addr: 2405:204:f109:105f:69be:db2b:9c8a:6051/64 Scope:Global
inet6 addr: fe80::b396:d285:b5b3:81c3/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8909 errors:0 dropped:0 overruns:0 frame:0
TX packets:8903 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9662594 (9.6 MB) TX bytes:1080952 (1.0 MB)

## Basic Linux commands with examples for Package Installation.
23. Install Packages in Linux using rpm command
You can use rpm command to install a package in Linux.

[root@elinuxbook ~]# rpm -ivh dhcp-3.0.5-23.el5.x86_64.rpm
warning: dhcp-3.0.5-23.el5.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing… ########################################### [100%]
1:dhcp ########################################### [100%]

rpm command with argument -qc will list configuration files of a particular package. Here I am listing configuration files of package Vsftpd FTP Server.
[root@elinuxbook ~]# rpm -qc vsftpd
/etc/logrotate.d/vsftpd.log
/etc/pam.d/vsftpd
/etc/vsftpd/ftpusers
/etc/vsftpd/user_list
/etc/vsftpd/vsftpd.conf
/etc/vsftpd/vsftpd_conf_migrate.sh

Update a installed package from It’s lower version to higher version using below command.
[root@localhost ~]# rpm -Uvh dhcp-4.1.1-51.P1.el6.centos.x86_64.rpm
Preparing… ########################################### [100%]
1:dhcp ########################################### [100%]

24. Install Package in Linux using yum command
Install a Package in Linux using yum command. Refer the command below.

[root@elinuxbook ~]# yum install dhcp
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirror.nbrc.ac.in
* extras: mirrors.nhanhoa.com
* updates: centos-hcm.viettelidc.com.vn
base | 3.7 kB 00:00
extras | 3.4 kB 00:00
updates | 3.4 kB 00:00
Resolving Dependencies
–> Running transaction check
—> Package dhcp.x86_64 12:4.1.1-51.P1.el6.centos will be installed
–> Finished Dependency Resolution

Dependencies Resolved

================================================================================
Package Arch Version Repository Size
================================================================================
Installing:
dhcp x86_64 12:4.1.1-51.P1.el6.centos base 823 k
.
.
Installed:
dhcp.x86_64 12:4.1.1-51.P1.el6.centos

Complete!

You can List installed packages using below command.
[root@elinuxbook ~]# yum list installed

List most recently installed packages using below command.
[root@elinuxbook ~]# yum list recent
Loaded plugins: fastestmirror, refresh-packagekit, security
Loading mirror speeds from cached hostfile
* base: mirror.nbrc.ac.in
* extras: centos-hn.viettelidc.com.vn
* updates: centos-hn.viettelidc.com.vn
Recently Added Packages
openjpeg.x86_64 1.3-16.el6_8 updates
openjpeg-devel.i686 1.3-16.el6_8 updates
openjpeg-devel.x86_64 1.3-16.el6_8 updates
openjpeg-libs.i686 1.3-16.el6_8 updates
openjpeg-libs.x86_64 1.3-16.el6_8 updates
tomcat6.noarch 6.0.24-105.el6_8 updates
tomcat6-admin-webapps.noarch 6.0.24-105.el6_8 updates

25. Check your installed Operating System details using uname command
Just uname command will show you the name of your currently installed operating system name.

elinuxbook@ubuntu:~$ uname
Linux

uname command with argument -a will display Operating System Name, Kernel Version, OS architecture and so on.
elinuxbook@ubuntu:~$ uname -a
Linux ubuntu 4.13.0-32-generic #35~16.04.1-Ubuntu SMP Thu Jan 25 10:13:43 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

uname command with argument -o will show your operating system type. Here It’s GNU/Linux.
elinuxbook@ubuntu:~$ uname -o
GNU/Linux

## Basic Linux commands with examples to check Network Connectivity.

26. Check Network connectivity in Linux using ping command
You can check network connectivity in Linux using ping command by sending packets. Refer the command below.
elinuxbook@ubuntu:~$ ping localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.393 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.083 ms
64 bytes from localhost (127.0.0.1): icmp_seq=3 ttl=64 time=0.091 ms
64 bytes from localhost (127.0.0.1): icmp_seq=4 ttl=64 time=0.091 ms

— localhost ping statistics —
4 packets transmitted, 4 received, 0% packet loss, time 3035ms
rtt min/avg/max/mdev = 0.083/0.164/0.393/0.132 ms

Normally ping command send’s unlimited packets. But you can ask ping command to send fixed packets by using argument -c. Here I wanted 3 packets hence set -c as 3. Refer the command below.
elinuxbook@ubuntu:~$ ping -c 3 localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.068 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.077 ms
64 bytes from localhost (127.0.0.1): icmp_seq=3 ttl=64 time=0.091 ms

— localhost ping statistics —
3 packets transmitted, 3 received, 0% packet loss, time 2017ms
rtt min/avg/max/mdev = 0.068/0.078/0.091/0.013 ms

ping command with argument -i will keep interval between packets as per mentioned time in Seconds. Here I have set Interval as 2 seconds.

elinuxbook@ubuntu:~$ ping -c 3 -i 2 localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.066 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.090 ms
64 bytes from localhost (127.0.0.1): icmp_seq=3 ttl=64 time=0.091 ms

— localhost ping statistics —
3 packets transmitted, 3 received, 0% packet loss, time 4028ms
rtt min/avg/max/mdev = 0.066/0.082/0.091/0.013 ms

27. Copy files & directories Securely over Network
You can copy files and directories in Linux over network using scp command. scp stands for Secure Copy.
scp root@10.10.0.125:/data/file.txt /root/

28. Securly take console/Remote of any system over network using ssh
Take remote of any system securely using ssh command. Refer the command below.
ssh root@10.10.0.125

Here we have tried to include all possible frequently used basic Linux commands with examples. If something missed out you can comment on comment box below.

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