freebsd man page for lastlog

LASTLOG(8)                                                  System Management Commands                                                  LASTLOG(8)

NAME
       lastlog - reports the most recent login of all users or of a given user

SYNOPSIS
       lastlog [options]

DESCRIPTION
       lastlog formats and prints the contents of the last login log /var/log/lastlog file. The login-name, port, and last login time will be
       printed. The default (no flags) causes lastlog entries to be printed, sorted by their order in /etc/passwd.

OPTIONS
       The options which apply to the lastlog command are:

       -b, --before DAYS
           Print only lastlog records older than DAYS.

       -C, --clear
           Clear lastlog record of a user. This option can be used only together with -u (--user)).

       -h, --help
           Display help message and exit.

       -R, --root CHROOT_DIR
           Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.

       -S, --set
           Set lastlog record of a user to the current time. This option can be used only together with -u (--user)).

       -t, --time DAYS
           Print the lastlog records more recent than DAYS.

       -u, --user LOGIN|RANGE
           Print the lastlog record of the specified user(s).

           The users can be specified by a login name, a numerical user ID, or a RANGE of users. This RANGE of users can be specified with a min
           and max values (UID_MIN-UID_MAX), a max value (-UID_MAX), or a min value (UID_MIN-).

       If the user has never logged in the message ** Never logged in** will be displayed instead of the port and time.

       Only the entries for the current users of the system will be displayed. Other entries may exist for users that were deleted previously.

NOTE
       The lastlog file is a database which contains info on the last login of each user. You should not rotate it. It is a sparse file, so its
       size on the disk is usually much smaller than the one shown by "ls -l" (which can indicate a really big file if you have in passwd users
       with a high UID). You can display its real size with "ls -s".

FILES
       /var/log/lastlog
           Database times of previous user logins.

CAVEATS
       Large gaps in UID numbers will cause the lastlog program to run longer with no output to the screen (i.e. if in lastlog database there is
       no entries for users with UID between 170 and 800 lastlog will appear to hang as it processes entries with UIDs 171-799).

shadow-utils 4.5                                                    01/25/2018                                                          LASTLOG(8)