Definition:
The word useradd means adding a user, i.e., creating a new user account in the system. Whenever there is a need to give someone access to a file or system resource, the admin uses this command to create that user. The admin can also form a group and add users to it to control access. This command is handy for organizing users and groups and assigning proper permissions.
Syntax:
useradd [options] username
Example:
Example 1 – Create a simple user
useradd shobha
Output:
(no output if successful)
Example 2 – Create a user with a home directory
useradd -m prabha
Output:
(no output if successful)
But you will be checking it.
ls /home
Output:
prabha shobha
Here, Shobha created a new home directory for Prabha.
Example 3 – Create a user with a specific shell
useradd -s /bin/bash ravi
Output:
(no output if successful)
To check it:
cat /etc/passwd | grep ravi
Output:
ravi:x:1003:1003::/home/ravi:/bin/bash
Example 4 – In error case
useradd shobha
Output:
useradd: user 'shobha' already exists
Options:
-m→ If you use this option with the command, it creates a home directory for the user.-d /path/to/home→ If you use this option with the command, it sets a custom home directory for the user.-s /bin/bash→ If you use this option with the command, it sets the default shell for the user.-u UID→ If you use this option with the command, it assigns a specific user ID (UID) to the new user.-g GROUP→ If you use this option with the command, it assigns a primary group to the new user.-G GROUP1, GROUP2→ If you use this option with the command, it assigns the user to additional (secondary) groups.-c "comment"→ If you use this option with the command, it adds a description or comment for the new user.-e YYYY-MM-DD→ If you use this option with the command, it sets an expiration date for the user account.-f DAYS→ If you use this option with the command, it specifies the number of days after a password expires until the user account is disabled.-p PASSWORD→ If you use this option with the command, it sets the encrypted password for the new user.