Question

Is there a way to get CPU usage in CentOS? I need to parse this information and graph it from a Perl script, so it should preferably be a simple tool that prints out one singular output.

Answer 1

I actually use /proc/stat for this.. here’s the important bits of the python I use for my dzen2 widget.

while(1):
    f = file("/proc/stat","r")
    fcon = f.read().split("\n")[0].split()
    new.user, unice, new.sys, new.idle, new.iowait = [
            int(x) for x in fcon[1:6] ]

    new.user += unice
    master.user = new.user - old.user

    master.sys = new.sys - old.sys
    master.idle   = new.idle - old.idle
    master.iowait = new.iowait - old.iowait

    maxval = master.user + master.sys + master.idle + master.iowait
    curval = master.user + master.sys + master.iowait

    old.copy(new)
    print (float(curval)/maxval) * 100 )
    time.sleep(1)

This prints a percentage use of the processor, by the second.

Wrong language, I know, but you should be able to get the gist of which columns of the output refer to what.