s6-linux-init
Software
skarnet.org

The s6-halt program

s6-halt sends a signal to process 1 in order to halt the machine; or, with the -f option, it performs an immediate hard shutdown.

Interface

     s6-halt [ -h | -p | -r ] [ -f ]

• s6-halt sends a signal to process 1.
• It then exits 0.

Options

• -h : halt. The command will order a halt (i.e. the system will be shut down, but the power will remain up), which means sending a SIGUSR2 to process 1. This is the default.
• -p : poweroff. The command will order a power off, which means sending a SIGUSR1 to process 1.
• -r : reboot. The command will order a reboot, which means sending a SIGINT to process 1.
• -f : force. The command will not send any signal to process 1; it will just sync the filesystems then tell the kernel to halt, poweroff or reboot. s6-reboot -f or s6-poweroff -f should be the last program executed in the lifetime of a machine, at the end of the shutdown script called by process 1 when it receives a signal telling it to shut down.