man--last

LAST,LASTB(1)         Linux System Administrator’s Manual        LAST,LASTB(1)

NAME
       last, lastb - show listing of last logged in users

SYNOPSIS
       last  [-R]  [-num]  [  -n num ] [-adFiowx] [ -f file ] [ -t YYYYMMDDHHMMSS ] [name...]
       [tty...]
       lastb [-R] [-num] [ -n num ] [ -f file ] [-adFiowx] [name...]  [tty...]

DESCRIPTION
       Last searches back through the file /var/log/wtmp (or the file designated  by  the  -f
       flag)  and  displays  a list of all users logged in (and out) since that file was cre-
       ated.  Names of users and tty’s can be given, in which case last will show only  those
       entries  matching the arguments.  Names of ttys can be abbreviated, thus last 0 is the
       same as last tty0.

       When last catches a SIGINT signal (generated by the interrupt key, usually  control-C)
       or a SIGQUIT signal (generated by the quit key, usually control-\), last will show how
       far it has searched through the file; in the case of the SIGINT signal last will  then
       terminate.

       The  pseudo  user  reboot  logs in each time the system is rebooted.  Thus last reboot
       will show a log of all reboots since the log file was created.

       Lastb is the same as last, except  that  by  default  it  shows  a  log  of  the  file
       /var/log/btmp, which contains all the bad login attempts.

OPTIONS
       -f file
              Tells last to use a specific file instead of /var/log/wtmp.

       -num   This is a count telling last how many lines to show.

       -n num The same.

       -t YYYYMMDDHHMMSS
              Display the state of logins as of the specified time.  This is useful, e.g., to
              determine easily who was logged in at a particular time --  specify  that  time
              with -t and look for "still logged in".

       -f file
              Specifies a file to search other than /var/log/wtmp.

       -R     Suppresses the display of the hostname field.

       -a     Display  the  hostname  in the last column. Useful in combination with the next
              flag.

       -d     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.

       -F     Print full login and logout times and dates.

       -i     This option is like -d in that it displays the IP number of  the  remote  host,
              but it displays the IP number in numbers-and-dots notation.

       -o     Read an old-type wtmp file (written by linux-libc5 applications).

       -w     Display full user and domain names in the output.

       -x     Display the system shutdown entries and run level changes.

NOTES
       The  files wtmp and 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 touch(1) command (for example, touch
       /var/log/wtmp).

FILES
       /var/log/wtmp
       /var/log/btmp

AUTHOR
       Miquel van Smoorenburg, [email protected]

SEE ALSO
       shutdown(8), login(1), init(8)

                                 Jul 31, 2004                    LAST,LASTB(1)
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