NAME

login — log into the computer

SYNOPSIS

DESCRIPTION

The login utility authenticates a user and starts a session for them on the current terminal. getty(8) runs it once a name has been typed; it is not normally run by hand.

Without a user, login prompts for one. Authentication and account checks go through PAM, using the “login” policy in /etc/pam.d/login; see pam.conf(5). After a failed attempt, login says “Login incorrect” and asks again. Past login-backoff failures it waits five seconds longer before each new attempt, and after login-retries failures it exits. A login that is not finished within login-timeout seconds is abandoned. The three values come from the “default” class in login.conf(5).

A user whose password has passed its change time is made to choose a new one before the session starts.

On success, login applies the user's login class (resource limits, priority, umask and environment), changes the terminal's owner to the user, records the session in /var/run/utmpx and /var/log/wtmpx, and runs the user's shell as a login shell in the home directory. Unless the class sets hushlogin or ~/.hushlogin exists, it first prints the message of the day.

login waits for the shell to exit, then closes the PAM session, records the logout and gives the terminal back to root.

The options are as follows:

-f

The user has already been authenticated; skip authentication.

-h hostname

The session comes from hostname.

-p

Keep the environment rather than starting from an empty one.

Only the superuser may run login.

ENVIRONMENT

The shell starts with HOME, SHELL, USER, LOGNAME, PATH, TERM and MAIL set, plus whatever the login class and the PAM modules add.

FILES

/etc/login.conf

login classes

/etc/motd

message of the day

/etc/nologin

refuses logins other than root's while it exists

/etc/pam.d/login

the PAM policy

/var/run/utmpx

current sessions

/var/log/wtmpx

session history

SEE ALSO

passwd(1), utmpx(3), login.conf(5), pam.conf(5), passwd(5), getty(8)

HISTORY

A login utility appeared in Version 1 AT&T UNIX. This implementation was written for OxideBSD.