Linux – Sudoers

Dear readers,

In this post, I am going to cover the sudoers in CentOS7. You all probably know that su means super user or substitute user and sudo means “do as su(per user)” :)

If you login to the system as root user, you are allowed to run all of the commands. I will try to perform several tasks as normal user for you to review the results.

Screen Shot 2016-05-24 at 18.53.49

Let’s try to run command by using sudo then.

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Linux – Granting permissions

Hello all,

In this blog, I am going to review file and folder permissions which are assigned to user , group and other objects.The very fundamental parameters that are needed to be considered when assigning permissions are User,Group,Others,Read,Write,Execute. In shortly, we can use ugo for user,group,others and rwx for read,write and execute. The table shown below is sufficient to express permissions in octal mode.

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Linux – User & Group Basics 2

Hey dear readers,

In this post, I am going to review user object creation, group object creation, group membership change tasks. The distribution I have setup is CentOS7.

Firstly, I will create few user objects. The very basic command to achieve this task is to run “useradd user_logon_name” .

Screen Shot 2016-05-23 at 19.50.37

As you see, the user is created without a password. That’s why, it can not be used to login to the system. To assign a password to the new user , you can run the passwd command as shown below.

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Linux – User & Group Basics 1

Hey all,

I am going to review basic user group management tasks such as user creation, group creation, group membership changes, the files where user,group objects are stored. I have a CentOS7 basic installation. Before jumping into hands-on’s, it should be good to remind you about /etc/passwd and /etc/group files.

/etc/passwd file stores user informations created in your linux OS and a sample view of /etc/passwd file is shown below.

Screen Shot 2016-05-22 at 18.37.43

Let’s scrutinize the meaning of fields at first.

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