LAST,LASTB(1) Linux System Administrator's Manual LAST,LASTB(1)
last, lastb - show listing of last logged in users
last [-R] [-num] [ -n num ] [-adiox] [ -f file ] [ -t YYYYMMDDHHMMSS ] [name...] [tty...]
lastb [-R] [-num] [ -n num ] [ -f file ] [ -t YYYYMMDDHHMMSS ] [-adiox] [name...]
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 created. 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.
-num This is a count telling last how many lines to show.
-n num The same.
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".
-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.
-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).
-x Display the system shutdown entries and run level changes.
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
Miquel van Smoorenburg, firstname.lastname@example.org
shutdown(8), login(1), init(8)
Jul 29, 1999 LAST,LASTB(1)