Linux Create User Account

Q. How do I create create a new Linux user account ? How do update or modify default Linux new user information? Using the command prompt (shell) tools, how do I add a user to the system? What are command line options for adding a user?

A. To create a new user account under any Linux distribution use command called useradd. The system administrator is responsible for creating account. Login as root user (or use sudo command).

useradd command syntax

useradd [options] {username}

Depending on command line options, the useradd command will update system files (/etc/passwd and /etc/shadow file with password) and may also create the new user's home directory and copy initial files.

Linux add a new user called rakhi

Type the command as follows:
useradd rakhi
Set a password for rakhi:
passwd rakhi
Without password user account will be in locked status. To unlock the account, you need to use above passwd command. Use passwd command to assign a password and set password aging guidelines.

Set account disable date

You can set date for the account to be disabled in the format YYYY-MM-DD with -e option while creating account itself:
useradd -e {yyyy-mm-dd} {username}
useradd -e 2008-12-31 jerry

Set default password expiry

The -f {days} option set number of days after the password expires until the account is disabled. (If 0 is specified, the account is disabled immediately after the password expires. If -1 is specified, the account is not be disabled after the password expires.)
useradd -f {days} {username}
useradd -e 2009-12-31 -f 30 jerry