.\" Copyright (C) 1998-2004 Miquel van Smoorenburg.
.\"
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.\" it under the terms of the GNU General Public License as published by
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.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\" GNU General Public License for more details.
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.TH "LAST, LASTB" "1" "October 2013" "util-linux" "User Commands"
.SH NAME
last, lastb \- show a listing of last logged in users
.SH SYNOPSIS
.B last
[options]
.RI [ username "...] [" tty ...]
.br
.B lastb
[options]
.RI [ username "...] [" tty ...]
.SH DESCRIPTION
.B last
searches back through the
.I /var/log/wtmp
file (or the file designated by the
.B \-f
option) and displays a list of all users logged in (and out) since that
file was created.  One or more
.IR usernames " and/or " ttys
can be given, in which case
.B last
will show only the entries matching those arguments.  Names of
.I ttys
can be abbreviated, thus
.B last 0
is the same as
.BR "last tty0" .
.PP
When catching a SIGINT signal (generated by the interrupt key, usually
control-C) or a SIGQUIT signal,
.B last
will show how far it has searched through the file; in the case of the
SIGINT signal
.B last
will then terminate.
.PP
The pseudo user
.B reboot
logs in each time the system is rebooted.  Thus
.B last reboot
will show a log of all the reboots since the log file was created.
.PP
.B lastb
is the same as
.BR last ,
except that by default it shows a log of the
.I /var/log/btmp
file, which contains all the bad login attempts.
.SH OPTIONS
.TP
.BR \-a , " \-\-hostlast"
Display the hostname in the last column.  Useful in combination with the
.B \-\-dns
option.
.TP
.BR \-d , " \-\-dns"
For non-local logins, Linux stores not only the host name of the remote
host, but its IP number as well.  This option translates the IP number
back into a hostname.
.TP
.BR \-f , " \-\-file " \fIfile\fR
Tell
.B last
to use a specific \fIfile\fR instead of
.IR /var/log/wtmp .
The
.B \-\-file
option can be given multiple times, and all of the specified files will be
processed.
.TP
.BR \-F , " \-\-fulltimes"
Print full login and logout times and dates.
.TP
.BR \-i , " \-\-ip"
Like
.B \-\-dns ,
but displays the host's IP number instead of the name.
.TP
.BI \- number
.TQ
.BR \-n , " -\-limit " \fInumber\fR
Tell
.B last
how many lines to show.
.TP
.BR \-p , " \-\-present " \fItime\fR
Display the users who were present at the specified time.  This is
like using the options
.BR \-\-since " and " \-\-until
together with the same \fItime\fR.
.TP
.BR \-R , " \-\-nohostname"
Suppresses the display of the hostname field.
.TP
.BR \-s , " \-\-since " \fItime\fR
Display the state of logins since the specified
.IR time .
This is useful, e.g., to easily determine who was logged in at a
particular time.  The option is often combined with
.BR \-\-until .
.TP
.BR \-t , " \-\-until " \fItime\fR
Display the state of logins until the specified
.IR time .
.TP
.BI \-\-time\-format " format"
Define the output timestamp
.I format
to be one of
.IR notime ,
.IR short ,
.IR full ,
or
.IR iso .
The
.I notime
variant will not print any timestamps at all,
.I short
is the default, and
.I full
is the same as the
.B \-\-fulltimes
option.  The
.I iso
variant will display the timestamp in ISO-8601 format.  The ISO format
contains timezone information, making it preferable when printouts are
investigated outside of the system.
.TP
.BR \-w , " \-\-fullnames"
Display full user names and domain names in the output.
.TP
.BR \-x , " \-\-system"
Display the system shutdown entries and run level changes.
.SH TIME FORMATS
The options that take the
.I time
argument understand the following formats:
.TS
l2 l.
YYYYMMDDhhmmss
YYYY-MM-DD hh:mm:ss
YYYY-MM-DD hh:mm	(seconds will be set to 00)
YYYY-MM-DD	(time will be set to 00:00:00)
hh:mm:ss	(date will be set to today)
hh:mm	(date will be set to today, seconds to 00)
now
yesterday	(time is set to 00:00:00)
today	(time is set to 00:00:00)
tomorrow	(time is set to 00:00:00)
+5min
-5days
.TE
.SH FILES
/var/log/wtmp
.br
/var/log/btmp
.SH NOTES
The files
.I wtmp
and
.I btmp
might not be found.  The system only logs information in these files if
they are present.  This is a local configuration issue.  If you want the
files to be used, they can be created with a simple
.BR touch (1)
command (for example,
.IR "touch /var/log/wtmp" ).
.SH AUTHORS
.MT miquels@cistron.nl
Miquel van Smoorenburg
.ME
.SH SEE ALSO
.BR login (1),
.BR wtmp (5),
.BR init (8),
.BR shutdown (8)
.SH AVAILABILITY
The last command is part of the util-linux package and is available from
.UR https://\:www.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
Linux Kernel Archive
.UE .