Command 'uptime' returns 'average'

The output of uptime depends on the uptime itself, i.e.

On one system

$ uptime 17:35pm up 5 days 9:24, 9 users, load average: 0.30, 0.28, 0.28 

thus, 12 fields.

On another system

uptime 17:36:15 up 8:44, 2 users, load average: 0.09, 0.30, 0.41 

And thus 10 fields. It may defer for your system, of course. I suppose that you switched on your machine at noon, which leads to an uptime of N days and 0 hours, where the latter is not display (or something like that).

As it seems that you want to have the last column anyhow, you can replace your awk command with

uptime | awk '{print $NF}' 

NF is the number of fields, and $NF therefore the last field of the line. It think this is more error-proof.

If you want the first load average, instead of the third, then you can do

uptime | awk '{print $(NF-2)}' 

For scripting purposes I find it easier to get the load averages directly from /proc/loadavg then to try and parse uptime's annoying output.

Example

$ cat /proc/loadavg 1.08 0.77 0.85 2/838 16771 

From man proc:

 /proc/loadavg The first three fields in this file are load average figures giving the number of jobs in the run queue (state R) or waiting for disk I/O (state D) averaged over 1, 5, and 15 minutes. They are the same as the load average numbers given by uptime(1) and other programs. The fourth field consists of two numbers separated by a slash (/). The first of these is the number of currently runnable kernel scheduling entities (processes, threads). The value after the slash is the number of kernel scheduling entities that currently exist on the system. The fifth field is the PID of the process that was most recently created on the system.