I think the ps command doesn't work very well because I want to see the current cpu usage from certain processes. When I create a webpage that loops infinitely the ps commando still says that apache is using 0.0%. ps -eo "%cpu %C %U %c %a" | grep apache (I also tried different options, without success) In the ps manpage I see this text: "%CPU shows the cputime/realtime percentage. It will not add up to 100% unless you are lucky. It is time used divided by the time the process has been running." .... Well I ain't lucky. Is there a way to see the real cpu usage and not the average? The "top" command shows the real cpu usage but I need its output to create a table for a webpage instead of seeing the top command continuesly.

If the "top" command shows the correct result you can just use something like this:
top -b -n 1 | grep apache
Check "man top" for more information. I'm basically starting top in batch mode and running it for a single iteration.
You probably cheched this, but note that if the webpage loop is client-side your server will not get hurt.

i tried this command, and it shows a list of apache processes running at 0.0, and one of them at 0.1.

actually apache doesn't need any resources, unless you really have a big server load. so a CPU load of 0.0 seems ok to me (and if i run top, apache is so far at the bottom, that i cant see it).

but you can test your command like this: start a find to list all files; this eats a lot of CPU/IO:

find /

open another terminal and enter

ps -eo "%cpu %C %U %c %a" | grep find

gives me:

4.0 find pu 4.0 chris find find /

seems to work!

Chris

Thanks dude. The "top" command does show the correct results, I just didn't know how to run it only once.

What do you mean by client-side? Anyway, when I load the webpage loop script "top" shows 99% cpu usage so that's correct.

And uh, what do you mean by client-side? I mean, the script runs on the server so isn't it always server-side?


(forgive my noobness :P)



edit: to the guy above:

The script is just a test to see if the commands show the correct results. When I load looping page apache has an cpu usage of 99%. When I use the "ps" command, it shows 0.0 and when I use "top" I see 99%. Kinda weird that the "ps" command show the cputime/realtime cpu usage.

One more thing, is it possible to get the correct CPU usage with the "ps" command? If it is, then that will save me some time editing my Perl script.

Got the same problem with multithreaded program: ps shows the cpu usage of the main thread only !... The option -m gives the cpu usage by thread. It's better...
However, I haven't found a way to get the cpu usage by process without having to sum the thread cpu usages with a perl script...

What about ps axu followed by | grep whatever?

tyler@localhost:~$ ps axuUSER       PID %CPU %MEM   VSZ  RSS TTY      STAT START   TIME COMMANDroot         1  0.0  0.0  1528  528 ?        S    10:50   0:00 init [2]root         2  0.0  0.0     0    0 ?        SN   10:50   0:00 [ksoftirqd/0]root         3  0.0  0.0     0    0 ?        S<   10:50   0:00 [events/0]root         4  0.0  0.0     0    0 ?        S<   10:50   0:00 [khelper]root        20  0.0  0.0     0    0 ?        S<   10:50   0:00 [kblockd/0]root        50  0.0  0.0     0    0 ?        S    10:50   0:00 [pdflush]root        51  0.0  0.0     0    0 ?        S    10:50   0:00 [pdflush]root        53  0.0  0.0     0    0 ?        S<   10:50   0:00 [aio/0]root        52  0.0  0.0     0    0 ?        S    10:50   0:00 [kswapd0]root       189  0.0  0.0     0    0 ?        S    10:50   0:00 [kseriod]root       210  0.0  0.0     0    0 ?        S<   10:50   0:00 [ata/0]root       304  0.0  0.0     0    0 ?        S    10:50   0:00 [kjournald]root       585  0.0  0.0     0    0 ?        S    10:50   0:00 [khubd]root      2458  0.0  0.0  1700  696 ?        Ss   10:51   0:00 dhclient -e -pf /daemon    2462  0.0  0.0  1640  444 ?        Ss   10:51   0:00 /sbin/portmaproot      2627  0.0  0.0  1584  624 ?        Ss   10:51   0:00 /sbin/syslogdroot      2630  0.0  0.1  2428 1444 ?        Ss   10:51   0:00 /sbin/klogdDebian-   2664  0.0  0.1  4212 1472 ?        Ss   10:51   0:00 /usr/sbin/exim4 -tyler     2669  0.0  0.1  2904 1472 ?        Ss   10:51   0:00 /usr/sbin/famd -Twnn       2673  0.0  0.3  5276 3944 ?        S    10:51   0:00 /usr/bin/Wnn4/jseroot      2680  0.0  0.0  1564  520 ?        Ss   10:51   0:00 /usr/sbin/inetdroot      2687  0.0  0.1  3428 1444 ?        Ss   10:51   0:00 /usr/sbin/sshdroot      2712  0.0  0.3  5016 3472 ?        Ss   10:51   0:00 /usr/bin/X11/xfsroot      2784  0.0  0.1  2760 1460 ?        S    10:51   0:00 /bin/bash /etc/rcroot      2785  0.0  0.1  2760 1460 ?        S    10:51   0:00 /bin/bash /etc/rcroot      2786  0.0  0.2  9020 2760 ?        S    10:51   0:00 /usr/bin/Xprt -acroot      2788  0.0  0.1  2760 1464 ?        S    10:51   0:00 /bin/bash /etc/rcdaemon    2795  0.0  0.0  1716  628 ?        Ss   10:51   0:00 /usr/sbin/atdroot      2855  0.0  0.0  1788  732 ?        Ss   10:51   0:00 /usr/sbin/cronroot      2861  0.0  0.2  8860 2324 ?        Ss   10:51   0:00 /usr/bin/gdmroot      2868  0.0  0.2  9204 2752 ?        S    10:51   0:00 /usr/bin/gdmroot      2870  0.0  0.0  1528  480 tty1     Ss+  10:51   0:00 /sbin/getty 38400root      2873  0.0  0.0  1528  480 tty4     Ss+  10:51   0:00 /sbin/getty 38400root      2875  0.0  0.0  1528  484 tty6     Ss+  10:51   0:00 /sbin/getty 38400root      2971  5.8  6.5 81604 67912 ?       S<L  10:51   0:49 /usr/X11R6/bin/Xroot      3069  0.0  0.0     0    0 ?        S    10:51   0:00 [kapmd]root      3102  0.0  0.0  1528  484 tty3     Ss+  10:51   0:00 /sbin/getty 38400root      3128  0.0  0.0  1528  484 tty5     Ss+  10:51   0:00 /sbin/getty 38400tyler     3165  0.0  0.8 18660 9324 ?        Ss   10:51   0:00 /usr/bin/gnome-setyler     3229  0.0  0.0  3004  880 ?        Ss   10:51   0:00 /usr/bin/ssh-agentyler     3232  0.1  0.7 10776 7476 ?        S    10:51   0:01 /usr/lib/gconf2/gtyler     3234  0.0  0.0  2284 1020 ?        S    10:51   0:00 /usr/bin/gnome-ketyler     3236  0.0  0.2  7112 2864 ?        Ss   10:51   0:00 /usr/lib/bonobo-aroot      3237  0.0  0.0  1528  480 tty2     Ss+  10:51   0:00 /sbin/getty 38400tyler     3249  0.0  0.2  7728 2684 ?        Ss   10:51   0:00 gnome-smproxy --styler     3251  0.0  0.8 20372 8592 ?        S    10:51   0:00 /usr/lib/control-tyler     3288  0.1  0.7 13704 7400 ?        Ss   10:51   0:00 metacity --sm-savtyler     3299  0.0  1.1 20952 12348 ?       Ss   10:51   0:00 gnome-panel --sm-tyler     3301  0.0  1.7 36076 17648 ?       Ss   10:51   0:00 nautilus --sm-contyler     3303  4.6  3.2 77188 34168 ?       Ss   10:51   0:38 /usr/bin/python /tyler     3305  0.1  0.7 46760 7636 ?        Ss   10:51   0:00 xmms --sm-client-tyler     3310  0.0  0.3 17368 3612 ?        S    10:51   0:00 /usr/lib/gnome-vftyler     3328  0.0  0.0  2220  764 ?        S    10:51   0:00 /usr/lib/nautilustyler     3333  0.0  0.9 18220 9404 ?        S    10:51   0:00 /usr/lib/gnome-patyler     3335  0.0  0.9 18136 9668 ?        S    10:52   0:00 /usr/lib/gnome-patyler     3349  6.8  4.1 112656 42820 ?      S    10:52   0:54 /usr/lib/mozilla-tyler     3575  0.0  0.1  3816 1924 ?        S    10:56   0:00 /usr/bin/xscreenstyler     3781 17.5  1.2 31500 13248 ?       R    11:05   0:00 gnome-terminaltyler     3782  0.0  0.0  2236  672 ?        S    11:05   0:00 gnome-pty-helpertyler     3783  0.0  0.1  4824 1672 pts/1    Ss   11:05   0:00 bashtyler     3787  0.0  0.0  2528  848 pts/1    R+   11:05   0:00 ps axu