How to Determine a System's Run Level

Display run level information by using the who -r command to determine a system's run level.

$ who -r

Use the who -r command to determine a system's current run level for any level except run level 0.

$ who -r
.       run-level 3  Oct 26 15:04      3      0  S
$

`run level 3`	Identifies the current run level.
`Oct 26 15:04`	Identifies the date of last run level change.
`3`	Is the current run level.
`0`	Identifies the number of times at this run level since the last reboot.
`S`	Identifies the previous run level.