🐧 Linux Server Administration: Working with Users, Groups & Permissions – TYBSc IT Practical Guide
Are you a TYBSc IT student learning Linux Server Administration? One of the core practicals you’ll encounter is about managing users, groups, and permissions in Linux. This blog will guide you through the practical tasks step by step with commands and explanations. Ideal for TYBSc IT Sem 5 students, beginners in Linux, or anyone preparing for Linux sysadmin interviews.
A) Creating and Managing Users
1. Add New User
sudo adduser john
Adding user `john' ...
Adding new group `john' (1001) ...
Adding new user `john' (1001) with group `john' ...
Creating home directory `/home/john' ...
Copying files from `/etc/skel' ...
New password:
Retype new password:
passwd: password updated successfully
2. Rename User
sudo usermod -l johnny john
(If successful, there will be no output.)
3. Delete User
sudo deluser johnny
Removing user `johnny' ...
Warning: group `johnny' has no more members.
Done.
4. Delete User with Home
sudo deluser --remove-home johnny
Removing user `johnny' ...
Removing home directory `/home/johnny' ...
Done.
B) Creating and Managing Groups
1. Create Group
sudo groupadd developers
(No output if successful.)
2. Add User to Group
sudo useradd -m anita sudo usermod -aG developers anita
(Commands execute silently if successful.)
3. View User Groups
groups anita
anita : anita developers
4. Delete Group
sudo groupdel developers
(No output if successful.)
C) File Permissions & Advanced Permissions
1. Check Permissions
ls -l test.txt
-rw-r--r-- 1 john john 0 Jun 1 09:30 test.txt
2. Change Permissions
chmod 755 test.sh
(No output if successful.)
3. Change Ownership
sudo chown root:root test.txt
(No output if successful.)
🔐 Sticky Bit (shared dir)
sudo mkdir /shared sudo chmod +t /shared ls -ld /shared
drwxrwxrwt 2 root root 4096 Jun 1 09:32 /shared
🔐 SUID (execute as owner)
sudo chmod u+s test.sh ls -l test.sh
-rwsr-xr-x 1 root root 1234 Jun 1 09:35 test.sh
🔐 SGID (execute as group)
sudo chmod g+s test.sh ls -l test.sh
-rwsr-sr-x 1 root root 1234 Jun 1 09:36 test.sh
✅ This practical covers:
- ✅ Creating and managing users using
adduser,usermod,deluser - ✅ Creating and managing groups using
groupadd,usermod,groupdel - ✅ Assigning file and directory permissions using
chmod,chown, and special permissions: SUID, SGID, and sticky bit
