Linux operating system is very powerful operating system . Linux is open source Unix like operating system the first release of Linux Kernel by Linus Torvalds on 17 september 1991 . Linux in today time comes in many flavours or say distribution called as Linux Distro. A Linux distro may consist of A Linux Kernel, some system softwares, Libraries and Device Drivers. Most popular Linux distributions are Ubuntu,Debian, Fedora,Linux mint. Linux distributions specially for server Purposes are also very popular in Large corporations and data centers.
you can see in this example.
One biggest challange for any one to learn Linux opration is not knowing of Basic commands that are the first need to operate any linux system without GUI(graphical user Interface). to solve this issue and make the opration easy now many Linux Distro. Comes with a default system software for Desktop GUI in which GNOME and KDE are the most popular ones.
Now I am going to describe you some very essential Linux Commands that any Linux enthusiast or learner should know.
1. mkdir: This command is used to create any directory in the present directory if you are in home directory this command will create a directory in home by the name you have given.
HOME$ mkdir test
The cursor will return after executing the command.
HOME$
2.cd : This command is used to change the directory where the user like to go.
Example: HOME $ cd test
HOME/test $
3. pwd: this command tells you the present working directory means in which directory in you are working in the above examples it will say as
$ pwd
HOME/test
4. rm : this command is used to remove and file or directory in current directory
HOME $ rm test
It will remove or delet the test directory.
5.ls : this Command will tell you that how many files or directory available in this current directory .
HOME$ ls
It will return
test
If you do not have use rm command to delet it.
6. ls -l : this command is used to list all the files in the current directory along with there permission level and the user and group on this system access .
7. chmod : this command is used to change the permission of any file to read write and execute
drwxrwx---
Here first letter d means it is directory next 3 letter are rwx means read write and execute permission to user ,next 3 letters are for groups read write and execute and last 3 are for others read write and execute permission.
In the above screen or you may see that.
Example :
chmod +x test #this command will give executable permission to the directory test.
8.alias: this command is used to substitute any command with the word of you choice.
Examples
alias clr= clear
Now in this terminal you can use use clr for clearing the screen,you can use any substitute word for any command but this susbtution will lost after terminal close . If you like make this permanent you may edit the .bashrc file for that command.
9.sudo : this command is used to gain elevated privilege as root user of the system. root user are equivalent to administrator of the windows system they have all the privilege of read write excited on the system. by default Ubuntu user names are added in sudoer file but not in the case of redhat where you have to add user to sudoer file at location /etc/
Example :
$ sudo apt install Python
Here apt is the package manager install is the install command and Python is the required program to install on the system.
apt package manager is used in debian based Linux distros like Ubuntu.
10.su : this Command is used to change user in the system . If like to change user from hari to shayam you may use it as su username to login and if You use su - it will change to root user
Examples:
su shyam to change user to shyam
su - to change user to root
11. passwd: this command is used to change or set new password to the user
Example :
$ passwd shayam # it will prompt to change password of shyam.
Important Note : in Linux system when you enter password there is no dot or dash will appear when you type password as like windows so it does not means the password is not entered.
12.history: this command will give you all the past command you have entered in that terminal.
You can see the output of history command.
13. touch: this command is used to make new files or say text file or script file inse the file created you may edit it with vim or nano text editors.
Example:
$ touch new.txt # this will create a text file names as new
14. nano: this basically not a command it is a text editor and very use full for bewoners to edit any configuration file or text file using nano command.
But before using it you should chek is it installed if not you may install it by command
$ sudo apt install nano
Example:
$ nano new.txt # it will open file new.txt with nano text editor after entering text you may exit from text editor by pressing ctrl+x and it prompt to say Y to save changes press Y to save .
15.ifconfig : this command tells you all the available interface configurations. It shows your loopback adapter ,eth adapters and alam adapters along with there current status with Ip addressees assigned to them.
Example:
Author : Bharat Kashyap
4/8/2020