login-update-utmpx, utx — update the login log and active login table
login-update-utmpx { boot | reboot | shutdown }
utx { boot | reboot | shutdown }
login-update-utmpx updates the utmpx(3) login log and active login table.
Invoked with the boot or reboot subcommands, it writes a new BOOT_TIME entry.
This is designed to be invoked at system bootstrap before any login services are started.
login-update-utmpx creates the files for the login log and the active login table if they do not already exist.
The entry can be later read with who -b or last reboot .
Invoked with the shutdown subcommand, it writes a new SHUTDOWN_TIME entry.
This is designed to be invoked at system shutdown after all login services have been stopped.
The entry can be later read with last reboot .
(On Linux operating systems, which do not have SHUTDOWN_TIME, the entry is a fake RUN_LVL entry that can be later read with who -r .)
On operating systems such as FreeBSD, note that login-update-utmpx always erases all entries from the active login table, as an effect of the pututmpx(3) library function.