Day 5 Of 90 Days Of Devops

Today I am going to discuss about the below mentioned topics in Day 5 of ⭐⭐#90daysofdevops ⭐⭐

✔User and Group Management in Linux

✔How to Give/edit the file permission in Linux

User Management Command in Linux

• To add a User

    $ sudo useradd -m manash
  

• To find out How many users are there

     $ cat /etc/passwd
  

  

• To add a group : group is a collection of user and we create a group such that if we want to give some specifice permission so it is better if we give that permission to group such that all the users in that group can also get the permission rather to give permission one by one to every user

    $ sudo groupadd devops   
    #Here the devops is the group name
  

• To append user in a group

    $ sudo usermod -aG devops manash 
    #Here -aG means append to group
    #Here devops is the name of the group in whcih we are appending user
    #manash is the user whcih we are appending to group
  

• To add multiple user to a group

    $ sudo gpasswd -M amrit,manash devops
    #here amrit,manash is the multiple user that we want to add to devops group
    #here -M means Multiple for multiple users
  

• To delete a group

    $ sudo groupdel devops
    #Here devops is the group name that we are deleting 
    #Note: keep in mind that even if we have deleted a group but still the 
    #users will exists
  

File Permission in Linux

• Command to check what permission we have for our files

$ ls -l
#Here ls means list it will list out all the files and directory 
#Here -l is the option that will give the complete description of the file/
#directory

• Here you are able to see that we are getting complete info about the files/directory

• if it is starting with d it means that it is a directory

• And then you are able to see that it is written like rw-rw-r-x

  that means r stands for read , w stands for write and x stands for execute

• There are three types of permission class

  User ,group,others and each one holds three places for the permission

  For example

  rw-rw-r--

  Here rw- is used for user where we have give read and write permission but no execute permission

  rw- is used for group where we have given read and write permission but no execute permission

  r-- is used for other user where we have just given the read permission

• read stand for 4, write stands for 2 and execute stands for 1

• so if we want to give the read and write and execute permission to user and only read permission to both group and other

• command that we will write is as below mentioned

    $ chmod 744 colors.txt
  

  Previous screenshot for the permission of the file

  

  After screenshot for the permission of the file

  

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Happy Learning All !!

Regards,

Amrit Manash