Cheatsheet & Examples: useradd

Create a Regular User Account

Example Usage: useradd john

What it does: Creates a new user account with default settings, including a home directory and default shell.

Command-line Arguments Explained:

• -m: Creates the user's home directory if it doesn't exist.
• -s: Sets the default shell for the new user.
• -c: Adds a comment field for the user's information.

Create a User with a Specific Shell

Example Usage: useradd -s /bin/zsh john

What it does: Creates a new user account with the specified shell (e.g., Zsh).

Command-line Arguments Explained:

• -s: Specifies the shell path (e.g., /bin/zsh).

Create a User with a Specific Shell and Home Directory

Example Usage: useradd -s /usr/bin/irbash -m john

What it does: Creates a new user account with a custom shell and a home directory.

Command-line Arguments Explained:

• -s: Specifies the shell path (e.g., /usr/bin/irbash).
• -m: Creates the home directory if it doesn't exist.

Add a User with a Comment

Example Usage: useradd -c "Custom User" john

What it does: Creates a new user account with a custom comment field.

Command-line Arguments Explained:

• -c: Adds a comment field for the user.

Set Expiration Date for a User

Example Usage: useradd -e 2025 john

What it does: Sets the expiration date for the user account.

Command-line Arguments Explained:

• -e: Sets the expiration date for the user account (format: YYYY-MM-DD).

Create a User with a Password

Example Usage: useradd -p <password> john

What it does: Creates a new user account with a specified password (note: -p is for existing users).

Command-line Arguments Explained:

• -p: Sets the password for the user account.