| LOGIN(1) | General Commands Manual | LOGIN(1) | 
login —
| login | [ -Ffps] [-aaddress] [-hhostname] [user] | 
login utility logs users (and pseudo-users) into the
  computer system.
If no user is specified, or if a user is specified and
    authentication of the user fails, login prompts for
    a user name. Authentication of users is done via passwords. If the user can
    be authenticated via S/Key, then the S/Key challenge is incorporated in the
    password prompt. The user then has the option of entering their Kerberos or
    normal password or the S/Key response. Neither will be echoed.
The options are as follows:
-a-a option specifies the address of the host
      from which the connection was received. It is used by various daemons such
      as telnetd(8). This option
      may only be used by the super-user.-F-F option acts like the
      -f option, but also indicates to
      login that it should attempt to rewrite an
      existing Kerberos 5 credentials cache (specified by the KRB5CCNAME
      environment variable) after dropping permissions to the user logging in.
      This flag is not supported under
      pam(8).-f-f option is used when a user name is
      specified to indicate that proper authentication has already been done and
      that no password need be requested. This option may only be used by the
      super-user or when an already logged in user is logging in as
    themselves.-h-h option specifies the host from which the
      connection was received. It is used by various daemons such as
      telnetd(8). This option may
      only be used by the super-user.-plogin discards any previous
      environment. The -p option disables this
    behavior.-sIf a user other than the superuser attempts to login while the
    file /etc/nologin exists,
    login displays its contents to the user and exits.
    This is used by shutdown(8)
    to prevent normal users from logging in when the system is about to go
  down.
Immediately after logging a user in, login
    displays the system copyright notice, the date and time the user last logged
    in, the message of the day as well as other information. If the file
    “.hushlogin” exists in the user's home
    directory, all of these messages are suppressed. This is to simplify logins
    for non-human users. login then records an entry in
    the wtmp(5) and
    utmp(5) files, executes
    site-specific login commands via the
    ttyaction(3) facility with
    an action of "login", and executes the user's command
  interpreter.
login enters information into the
    environment (see environ(7))
    specifying the user's home directory (HOME), command interpreter (SHELL),
    search path (PATH), terminal type (TERM) and user name (both LOGNAME and
    USER).
The user's login experience can be customized using login class capabilities as configured in /etc/login.conf and documented in login.conf(5).
The standard shells,
    csh(1) and
    sh(1), do not fork before
    executing the login utility.
login appeared in Version 6
  AT&T UNIX.
| November 19, 2008 | NetBSD 9.4 |