Linux uses groups in order to share resources in a easy way. In general a resource will have a user, group and other access rights. In this tutorial we will learn how to add user to a Linux group and its variations like creating group, deleting group, listing group members etc. Linux Groups Linux groups are organizational units used to organize and administrator user account and rights. Especially for privilege...
Ubuntu is a popular distributions used by a lot of companies as Desktop and Server. As a system administrator one of the most recurring job is changing existing user group. In this tutorial we will look how to accomplish this task and some helper commands about this. Primary Group Primary group specifies the user first group which will be used in file creation and other operations. For example if a...
chmod is very useful tool to manage file modes like read write execute. One of the most used option for chmod is +x which stands for execution rights. In this tutorial we will look different use cases for user or owner, group and others roles. List Current User and Group Of A File We generally need to know given file current user and group. We will use ls command with -al options in...
Linux users can be added with different ways. but one of the most used way is adding them throughout the shell because Linux admins loves shell usage. In this tutorial we will look how to add user into a Ubuntu, Kali, Mint, Debian box and provide or change required parameters. We will also look user deletion. Root Privileges In order to add or remove user from a Linux box we...
passwd command is used to change password and provides information about Linux accounts. Normal or root user can change passwords. Normal user can only change his own password in the other hand root can change all users passwords. Passwords related information is stored in /etc/passwd file. Only password which is stored as hash is stored in /etc/shadow . Password File As stated previously user account related information is stored in /etc/passwd . There is information...
I have a lot of users in my Linux servers. Security is important for me. I know that one of the important security measure is passwords. The length, complexity, change period etc. How can I force user to change password in first login? We will use change command to force user change password in the first login. Check Current Status We will check current user password status with chage command like...
The problem is we want to change the already created user name or user id. As we know there is a lot of configuration those rely on the user id like permissions. We will use usermod command to make this change. Keep in mind this changes will effects system wide. List User Info Before starting to big changes we will list users detailed info with cat command like below.
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$ cat /etc/passwd | grep ismail |
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Linux passwords are used to authenticate users. Linux passwords was hold in /etc/passwd file with other user related information like default shell, home directory path etc. Now in modern Linux distributions holds passwords in /etc/shadow file which have restricted access. This file holds user passwords as hash values with salt. Hashing and salting makes passwords more secure. Change Current User Password To change a user password we need password change...
I have Linux servers. There is a lot of different remote connection services like ssh, telnet, vnc, X11, konsole etc. I want to learn who is logged currently. And get details like connection way, connection time IP address etc. These information may become very crucial. There different commands to get this information. w Command For Connected Users w is very interesting command which can provide information about currently logged in...
In Linux users may have different groups registered. By default adding a user to the Linux system will create new user. There are different commands to change user group one of them is useradd which actually create new user and sets given group to the newly created user. As always we need root privileges to change user group. List Users Before starting to add user into a group we will...
