useradd

Basic Usage

Create a standard user with a home directory.

useradd -m [username]

Create a user with a specific full name (comment).

useradd -c "[comment]" [username]

Set the password for the new user immediately.

passwd [username]

Advanced & Professional Scenarios

System Users

Create a system user (no home directory, no login shell). Useful for running services.

useradd -r -s /bin/false [username]

Create a system user with a specific home directory for application data.

useradd -r -m -d /opt/myapp -s /bin/bash [username]

Group Management

Create a user with a specific primary group.

useradd -g [group] [username]

Create a user and add them to multiple secondary groups.

useradd -G [groups] [username]

Create a user with a custom User ID (UID).

useradd -u 1500 [username]

Security & Expiry

Create a user with an account expiry date.

useradd -e [expiry_date] [username]

Create a user whose password expires after a specific number of days.

useradd -f 30 [username]

Custom Home & Shell

Create a user with a non-standard home directory location.

useradd -m -d /data/users/[username] [username]

Create a user with a specific shell (e.g., Zsh).

useradd -s /usr/bin/zsh [username]

Skeleton Directory

Use a custom skeleton directory (template files like .bashrc) when creating the home directory.

useradd -m -k /etc/skel_custom [username]

Default Configuration

View default values for new users.

useradd -D

Change the default shell for future users.

useradd -D -s /bin/zsh