HardenedBSD/usr.bin/last/last.1
David Greenman c83d3f4574 Fixed a bug that caused last(1) to be extremely slow in some cases, and
made other performance improving changes. This improves the performance
of last(1) by as much as 32 times in some cases, and in more typical cases
is about twice as fast.
Added a BUGS section to the manual page to describe the behavior of last(1)
when a login shell terminates abnormally (and thus doesn't write a logout
record to the wtmp file).
1995-10-17 18:26:43 +00:00

129 lines
3.9 KiB
Groff

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.\" @(#)last.1 8.1 (Berkeley) 6/6/93
.\"
.Dd June 6, 1993
.Dt LAST 1
.Os BSD 4
.Sh NAME
.Nm last
.Nd indicate last logins of users and ttys
.Sh SYNOPSIS
.Nm last
.Op Fl Ns Ar n
.Op Fl f Ar file
.Op Fl h Ar host
.Op Fl t Ar tty
.Op user ...
.Sh DESCRIPTION
.Nm Last
will list the sessions of specified
.Ar users ,
.Ar ttys ,
and
.Ar hosts ,
in reverse time order. Each line of output contains
the user name, the tty from which the session was conducted, any
hostname, the start and stop times for the session, and the duration
of the session. If the session is still continuing or was cut short by
a crash or shutdown,
.Nm last
will so indicate.
.Pp
.Bl -tag -width indent-two
.It Fl f Ar file
.Nm Last
reads the file
.Ar file
instead of the default,
.Pa /var/log/wtmp .
.It Fl Ar n
Limits the report to
.Ar n
lines.
.It Fl t Ar tty
Specify the
.Ar tty .
Tty names may be given fully or abbreviated, for example,
.Dq Li "last -t 03"
is
equivalent to
.Dq Li "last -t tty03" .
.It Fl h Ar host
.Ar Host
names may be names or internet numbers.
.El
.Pp
If
multiple arguments are given, the information which applies to any of the
arguments is printed, e.g.,
.Dq Li "last root -t console"
would list all of
.Dq Li root Ns 's
sessions as well as all sessions on the console terminal. If no
users, hostnames or terminals are specified,
.Nm last
prints a record of
all logins and logouts.
.Pp
The pseudo-user
.Ar reboot
logs in at reboots of the system, thus
.Dq Li last reboot
will give an indication of mean time between reboot.
.Pp
If
.Nm last
is interrupted, it indicates to what date the search has
progressed. If interrupted with a quit signal
.Nm last
indicates how
far the search has progressed and then continues.
.Sh FILES
.Bl -tag -width /var/log/wtmp -compact
.It Pa /var/log/wtmp
login data base
.El
.Sh SEE ALSO
.Xr lastcomm 1 ,
.Xr utmp 5 ,
.Xr ac 8
.Sh BUGS
If a login shell should terminate abnormally for some reason, it is likely
that a logout record won't be written to the wtmp file. In this case,
.Nm last
will indicate the logout time as "shutdown".
.Sh HISTORY
.Nm Last
appeared in
.Bx 3.0 .