NAME
login —
log into the computer
SYNOPSIS
login |
[-fp] [-h
hostname] [user] |
DESCRIPTION
Thelogin 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.
The options are as follows:
-f- The
-foption 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- The
-hoption 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. -p- By default,
logindiscards any previous environment. The-poption disables this behavior.
If the file /etc/nologin exists,
login dislays its contents to the user and exits.
This is used by
shutdown(8) to prevent 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, such as
uucp(1). Login then records an entry in the
wtmp(5) and
utmp(5) files and executes the user's command interpretor.
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 standard shells,
csh(1) and sh(1), do not fork before executing the
login utility.
FILES
- /etc/motd
- message-of-the-day
- /etc/nologin
- disallows logins
- /var/run/utmp
- current logins
- /var/log/lastlog
- last login account records
- /var/log/wtmp
- login account records
- /var/mail/user
- system mailboxes
- .hushlogin
- makes login quieter
SEE ALSO
chpass(1), passwd(1), rlogin(1), getpass(3), utmp(5), environ(7),
HISTORY
A login appeared in
Version 6 AT&T UNIX.