Adding users

To add a user:

  1. Log in as root.
  2. Use passwd:
    passwd new_username
    Note: Make sure that the user name is no longer than 14 characters; otherwise, that user won't be able to log in.

If you specify a user name that's already registered, passwd assumes you want to change their password. If that's what you want, just type in the new password and then confirm it. If you don't wish to change the user's password, press CtrlC to terminate the passwd utility without changing anything.

If the user name isn't already registered, passwd prompts you for account information, such as the user's group list, home directory, and login shell. The /etc/default/passwd configuration file specifies the rules that determine the defaults for new accounts. For more information, see the description of this file in the documentation for passwd.

The prompts include:

User id # (default)
Specify the numeric user ID for the new user. By default, no two users may share a common user ID, because applications won't be able to determine the user name that corresponds to that user ID.
Group id # (default)
Choose a numeric group ID that the user will belong to after initially logging in.
Note: The passwd utility doesn't add the new user to the group's entry in the /etc/group file; you need to do that manually using a text editor. See Defining Groups for more details.
Real name ()
Enter the user's real name. The real name isn't widely used by system utilities, but may be used by applications such as email.
Home directory (/home/username)
Enter the pathname of the user's home directory, usually /home/username. The passwd utility automatically creates the directory you specify. If the directory already exists, passwd by default prompts you to select a different pathname. For information on disabling this feature, see the description of /etc/default/passwd in the documentation for passwd.
Login shell (/bin/sh)
This is the program that's run once the user logs in. Traditionally, this is the shell (/bin/sh), giving the user an interactive command line upon logging in.
Note: You can specify any program as the login shell, but you can't pass command-line arguments to it.

Instead of specifying a custom program within the account entry, you should customize the user's .profile file in their home directory; /bin/sh runs this profile automatically when it starts up. For more information, see Configuring Your Environment.

New password:
Specify the initial password for the account. You're asked to confirm it by typing it again.