How To Find The Last Person Who Log Into Linux

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

SYNOPSIS
       last  [-R]  [-num]  [  -n  num  ]  [-adiox]  [ -f file ] [ -t YYYYMMDDHHMMSS ] [name...]
       [tty...]
       lastb [-R] [-num] [ -n num ] [ -f file ] [-adiox] [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 created.
       Names of users and ttyâs 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 termi-
       nate.

       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.