Linux

As we said in Permissions and Ownership article, all files are owned by a user, a primary group and a world (everybody, others) group. If we list directory content with the command: ls -l we can see examples of the ownership. In our example, we created these files as the cicnavi user and that’s why the files … Read moreChange Permissions For Files and Folders in Linux

File system permissions in Linux are a little bit different than permissions in Microsoft Windows. File system permissions in the UNIX world use the POSIX standard, which basically says that every file and directory is owned by both a user and group. Every user has a primary group membership. When any any file is created by … Read moreFile Permissions and Ownership in Linux

Before you start Objectives: Learn how to set or change passwords for users on Linux machines. Prerequisites: no prerequisites. Key terms: passwd, Linux, administration, reset, set, management  Working With Passwords Today, we won’t see passwords in the /etc/passwd file any more. Instead, they are moved to the /etc/shadow password file, where they are encrypted. By default, shadow passwords … Read moreUsers and Passwords in Linux

Before you start Objectives: Learn what is root account, how should it be used, and how to change to it to execute commands. Prerequisites: no prerequisites. Key terms: root, administrator, Linux, system, su command. su –  root User The root user account on Linux system is created during the installation process and is a superuser which can perform … Read moreRoot User in Linux

Before you start Objectives: Learn how to allow users to run administrative commands using sudo. Prerequisites: you have to know how to manage users and how to manage groups in Linux. Key terms: sudo, root, user, command, Linux, sudoers file.  sudo sudo is a very useful tool used to delegate administrative rights to other users. One of the advantages (or … Read moreAdministrative Rights and Users in Linux

Before you start Objectives: Learn what are quotas, and how to configure quotas on Ubuntu machine. Prerequisites: no prerequisites. Key terms: quota, Ubuntu, configuration  Quotas Quotas limit the amount of space users and groups have available for either the number of files and directories they can create or the total size of all their files and directories. File system … Read moreQuota Management in Ubuntu

Before you start Objectives: Learn how to create new groups, manage existing ones, and how to change group membership in Linux. Prerequisites: no prerequisites. Key terms: groupadd, groupmod, groupdel, usermod, Linux  Creating and Managing Groups To add a new group we can use the ‘groupadd’ command. If we only enter the ‘groupadd’, we will see the syntax of … Read moreGroup Management in Linux

Before you start Objectives: Learn which files hold user information, how to add new user, how to modify existing user, and how to set a password for specific user. Prerequisites: no prerequisites. Key terms: password, user management, passwd file, useradd, usermod, userdel  Passwd File In early days of Linux, we basically had to use the text editor to … Read moreManaging Users in Linux

Before you start Objectives: Learn what is user account, what is passwd and group file, and how are those files structured. Prerequisites: no prerequisites. Key terms: Linux, passwd, group, shadow, gshadow, user account, user group. User Account and User Groups User account in any OS help us to control who can log on to a system, and which … Read moreIntroduction to Users and Groups in Linux