The
halt
and
halt
utilities flush the file system cache to disk, send all running processes
a
SIGTERM
(and subsequently a
SIGKILL
and, respectively, halt or restart the system.
The action is logged, including entering a shutdown record into the
wtmp(5)
file.
The options are as follows:
-d
The system is requested to create a crash dump.
This option is
supported only when rebooting, and it has no effect unless a dump
device has previously been specified with
dumpon(8).
-k kernel
Boot the specified
kernel
on the next system boot.
If the kernel boots successfully, the
default
kernel will be booted on successive boots, this is a one-shot option.
If the boot fails, the system will continue attempting to boot
kernel
until the boot process is interrupted and a valid kernel booted.
This may change in the future.
-l
The halt or reboot is
not
logged to the system log.
This option is intended for applications such as
shutdown(8),
that call
halt
or
halt
and log this themselves.
-n
The file system cache is not flushed.
This option should probably not be used.
-p
The system will turn off the power if it can.
If the power down action fails, the system
will halt or reboot normally, depending on whether
halt
or
halt
was called.
-q
The system is halted or restarted quickly and ungracefully, and only
the flushing of the file system cache is performed (if the
-n
option is not specified).
This option should probably not be used.
The
fasthalt
and
fastboot
utilities are nothing more than aliases for the
halt
and
halt
utilities.
Normally, the
shutdown(8)
utility is used when the system needs to be halted or restarted, giving
users advance warning of their impending doom and cleanly terminating
specific programs.
