Allow a privileged user to change system state. Default behavior is to terminate user processes, taking system down from multi-user state (state 2) to single-user state. That is, only the system console provides access. shutdown sends a warning message, waits 60 seconds, sends a final message, waits another 60 seconds, and finally prompts for confirmation. shutdown is the SVR4 alternative to halt or reboot.
Use a grace-period of
n seconds instead of 60.
Tell the init command to place system in state
Single-user state (the default).
Shutdown for safe power-off.
Like s, but mount multi-user file systems.
Stop system; go to firmware mode.
Stop system and then reboot.
Suppress the default prompt for confirmation.