Introduction

As we are learning Devops, linux is very basic and important part of the Devops's journey as around 50 %-60% of devops depends on it. Linux is an open-source operating system whose source code is available for modification and commercial and non-commercial distribution under the guidelines of the GNU General Public License.

• Linux is a freely available open-source OS.

• Linux maintians privacy of the user and lot more secure than windows OS.

• Linux is easy to install and network friendly.

  Linux Basic Commands

  File and Directory commands

• ls - Lists all the files and directories inside the current directory in which you are.

• ls -a - Lists all the files and directories in the current directory along with the hidden files.

• ls -l - Lists all the files and directories in the current directory with the details.

• ls -al - Lists files and directories of the current directory along with the details like permissions (read, write, execute), owner, file/dir size, etc.

• cd - This command is used to move to root directory.

• cd .. - This is used to move one level up directory.

• cd dirName - This command is used to move from one directory to particular directory. Ex: cd Desktop

• mkdir - This command creates a directory. Ex: mkdir devops

• rmdir - This command removes a directory. Ex: rmdir devops

• mv fileName “new file path” - This command moves file to specified path. Ex: mv file1.txt Docs/

• mv fileName newName - This command changes name of the file to newName. Ex:mv file1.txt file2.txt

• pwd - It prints present working directory.

  File permission commands

  There are three types of people accessing files i.e., user, group and others.CHMOD method is used to give permission to files.

  4 - read(r), 2 - write(w), 1 - execute(x) i.e., (4+2+1=7)

    chmod 777 - read,write and execute for all.
    chmod 755 - rwx for user, rx for group and others.
  

Disk Usage Commands

• du pathofdirectory - To find out the disk usage summary.

• du -h pathofdirectory - This will bring up your information in human readable format

• du -sh nameofdirectory - This is to find out total disk usage

  System Information Commands

• who - It gives logged in name of user, date and time and remote hostname of user.

• whoami - It gives name of logged in user.

• hostname - Shows the name of the system host.

• whereis fileName - It gives possible locations of fileName.

• date - This command is used to show the current date and time.

• cal - Shows the calendar of the current month.

• clear - Clears the terminal i.e. no previous command will be visible on the screen now.

  Environment Variable Commands

• env - This command displays all the environment variables.

• echo $Variable - This command displays the environment variable.

  Root Commands

5 ways to become a sudo user in Linux OS

• sudo -i

• sudo -s

• sudo su -

• su -root

• su -

I hope these commands help in learning basics of linux. I will keep on updating this commands as I learn in future.

Please like and comment and drop any suggestions if it is there in comment section.