login - log on the computer
login [-fIpq] [-d domain] [-h hostname] [user] ...
The login(1) utility logs users on the computer system.
If no user is specified, or if a user is specified and authentication of the user fails, login(1) prompts for a user name. Authentication of users is done through passwords.
On Interix, the login(1) program displays a domain name in parentheses. If the user does not specify a domain name as part of the user name, the user is assumed to be in the displayed domain. This default domain is derived from the system registry (see NOTES later in this topic). If no registry entry exists, the result is taken from a call to getpdomain(2).
The login(1) utility takes the following options:
If the file /etc/nologin exists, the content of the file is printed and the process exits, preventing login.
Normally, the login(1) utility prints the system copyright notice and notifies the user of new mail, and indicates whether either the account or the password will expire in the next two days. If the file .hushlogin exists in the user's home directory, these messages are not displayed.
The login(1) utility enters information into the environment specifying the user's home directory (HOME), command interpreter (SHELL), search path (PATH), terminal type (TERM) and user name (both LOGNAME and USER).
The standard shells, csh(1) and sh(1), contain a special built-in command and an alias, respectively, for login. If you invoke login in this manner, the shells do not fork before executing the login(1) utility.
The following files are used by login(1):
The default domain presented in the login banner can be changed by setting the Windows registry variable HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Services For Unix\PrincipalDomain to the name of the domain.
getpdomain(2)