Re: Display system monitoring counter on hard-status line?

[Karl.]

On Wed, Sep 05, 2007 at 12:13:19AM -0400, cga2000 wrote:
> As to %CPU, I couldn't find anything useful in /proc,   ...SNIP...

This isn't quite directly useful, but here's a snippet of lua code I use 
for getting cpu usage for the status bar of my window manager:

    f=io.open('/proc/stat','r')
    s=f:read('*l')
    f:close()

    _, _, t_usr, t_nice, t_sys, t_idle = string.find(s, 
"^cpu%s+(%d+)%s+(%d+)%s+(%d+)%s+(%d+)")
    t_total = t_usr + t_nice + t_sys + t_idle
    t_step_jiffies = t_total - t_total_prev
    c_used = 1 - (t_idle - t_idle_prev) / t_step_jiffies
    t_total_prev, t_idle_prev = t_total, t_idle


It reads a bunch of values from the /proc/stat line that starts with 
'cpu', then it has to figure the total time elapsed (t_total), and then
time elapsed since last we ran the calculation (t_step_jiffies).  Then 
we can figure out what the cpu usage was (c_used).  Lastly we store away 
the current values for use next time we run the calculation.

(hopefully I haven't edited out anything relevant from the snippet, or 
even completely messed it up!)

So, what I'm trying to say, is that I don't know a quick one-stop way to 
get cpu usage from proc.  

Furthermore, there are slightly different views of what 'cpu usage' 
means - it seems that some usage displays don't include t_nice, I think 
because that time is somewhat available to the user rather than the 
processor being busy and you not being able to do anything about it.  
(am I making any sense?)

> I'm also looking for something that would help monitor network traffic 
> .. Not sure this makes sense, but I was thinking something that 
> displays UP/DOWN Kb's, maybe?
> 
> Not sure where I could get that from.

have a look at /proc/net/dev


A completely different approach, which I used briefly but abandoned for 
various reasons, is to run conky in stdout mode.  In this mode you can 
set up all sorts of status monitors and have it spit them out on stdout, 
ready to be piped into something.

Karl.
-- 
http://mowson.org/karl