Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. It only takes a minute to sign up.
Sign up to join this community
I'm trying to make a small command that will find the processes that use the most CPU power.
Firstly, I use ps aux > file.txt and then cut -c 16-20 file.txt | sort -n | tail -5.
The result I get is this:
1.0
2.7
8.
14.5
14.5
So my question is how can I have both the %CPU usage and the other fields outputted together?
The correct answer is:
ps --sort=-pcpu
For top 5:
ps --sort=-pcpu | head -n 6
So you can specify columns without interfering with sorting.
Ex:
ps -Ao user,uid,comm,pid,pcpu,tty --sort=-pcpu | head -n 6
Note of 'ckujau': --sort is supported by ps from procps, other implementations may not have this option.
--sort is only supported by ps from procps, other implementations may not have this option.
Sort on the appropriate field (by default defined as whitespace to non-whitespace transition), in my case it is the 3rd one:
ps aux | sort -n -k 3
One annoyance with the accepted solution is that the headers for the different columns will get included in the output. Another issue being that when you use the switch -x to ps it will provide the full command lines for some programs, which can run on and become a nuisance in the output.
Annoying command-lines
saml 18174 7.3 3.2 1174896 259756 ? Sl Aug27 132:38 /opt/google/chrome/chrome --type=renderer --lang=en-US --force-fieldtrials=AsyncDns/AsyncDnsB/ForceCompositingMode/disable/InfiniteCache/No/OmniboxHQPReplaceHUPProhibitTrumpingInlineableResult/Standard/OmniboxSearchSuggestTrialStarted2013Q1/7/OneClickSignIn/Standard/Prerender/PrerenderControl/SendFeedbackLinkLocation/default/Test0PercentDefault/group_01/UMA-Dynamic-Binary-Uniformity-Trial/default/UMA-Session-Randomized-Uniformity-Trial-5-Percent/group_17/UMA-Uniformity-Trial-1-Percent/group_20/UMA-Uniformity-Trial-10-Percent/group_07/UMA-Uniformity-Trial-20-Percent/default/UMA-Uniformity-Trial-5-Percent/group_04/UMA-Uniformity-Trial-50-Percent/group_01/ --enable-crash-reporter=4061BD10D0DC127169CE2132BC3FF8EC,Fedora release 14 (Laughlin) --extension-process --renderer-print-preview --disable-webgl --disable-pepper-3d --disable-gl-multisampling --disable-accelerated-compositing --disable-accelerated-2d-canvas --disable-accelerated-video-decode --channel=18086.4.1423385819
root 1764 7.7 0.3 163692 28928 tty1 Ss+ Aug21 817:49 /usr/bin/Xorg :0 -nr -verbose -auth /var/run/gdm/auth-for-gdm-fADI0V/database -nolisten tcp vt1
Chrome especially can be quite annoying when looking at ps output like this!
Headers in output
$ ps auf | sort -nk 3 | head -20
...
root 1741 0.0 0.0 4140 400 tty5 Ss+ Aug21 0:00 /sbin/mingetty /dev/tty5
root 1743 0.0 0.0 4140 400 tty6 Ss+ Aug21 0:00 /sbin/mingetty /dev/tty6
saml 13780 0.0 0.0 115088 4216 pts/13 Ss Aug27 0:00 bash
saml 20432 0.0 0.0 6308 400 pts/9 S+ Aug27 0:00 \_ inotifywatch -e CREATE /etc
saml 8206 0.0 0.0 115296 1108 pts/6 Ss+ Aug21 0:03 bash
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
saml 29352 0.1 0.5 661848 42960 pts/13 Sl+ 17:59 0:18 \_ irb
...
You can see the header mixed in at the 7th line in the output.
Getting rid of the headers
ps provides a switch for disabling the display of these column headers. It's pretty easy to use, simply add the --no-heading switch.
$ ps aux --no-heading | sort -nk 3 | head -10
68 1481 0.0 0.0 38592 2144 ? Ssl Aug21 0:28 hald
68 1527 0.0 0.0 18016 672 ? S Aug21 0:01 /usr/libexec/hald-addon-acpi
avahi 1333 0.0 0.0 27872 1172 ? S Aug21 0:01 avahi-daemon: running [grinchy.local]
avahi 1334 0.0 0.0 27752 20 ? S Aug21 0:00 avahi-daemon: chroot helper
dbus 1307 0.0 0.0 22716 1900 ? Ss Aug21 1:03 dbus-daemon --system
gdm 1879 0.0 0.0 317220 2740 ? Sl Aug21 0:00 /usr/libexec/polkit-gnome-authentication-agent-1
ntp 3060 0.0 0.0 32600 2152 ? Ss 20:05 0:00 ntpd -u ntp:ntp -p /var/run/ntpd.pid -g
root 1 0.0 0.0 19420 1004 ? Ss Aug21 0:01 /sbin/init
root 1006 0.0 0.0 0 0 ? S Aug21 0:00 [kvm-irqfd-clean]
root 1020 0.0 0.0 0 0 ? S Aug21 2:02 [kdmflush]
Or like this:
$ ps auf --no-heading | sort -nk 3 |head -10
root 1735 0.0 0.0 4140 400 tty2 Ss+ Aug21 0:00 /sbin/mingetty /dev/tty2
root 1737 0.0 0.0 4140 400 tty3 Ss+ Aug21 0:00 /sbin/mingetty /dev/tty3
root 1739 0.0 0.0 4140 400 tty4 Ss+ Aug21 0:00 /sbin/mingetty /dev/tty4
root 1741 0.0 0.0 4140 400 tty5 Ss+ Aug21 0:00 /sbin/mingetty /dev/tty5
root 1743 0.0 0.0 4140 400 tty6 Ss+ Aug21 0:00 /sbin/mingetty /dev/tty6
saml 13780 0.0 0.0 115088 4216 pts/13 Ss Aug27 0:00 bash
saml 20432 0.0 0.0 6308 400 pts/9 S+ Aug27 0:00 \_ inotifywatch -e CREATE /etc
saml 2098 0.0 0.0 115508 3148 pts/9 Ss Aug22 0:05 bash
saml 27134 0.0 0.0 115496 6768 pts/18 Ss Aug27 0:02 bash
saml 3248 0.0 0.0 115076 1024 pts/0 Ss+ Aug21 0:00 bash
Take control of the columns being displayed.
This can seem like a pain, but if you're scripting the capture of ps output it isn't too bad. A command like this will mimic the output of ps aux, except swap out the longer form of the COMMAND column with a shorter version that just shows the executable's name.
$ ps ax --no-headings -o user,pid,%cpu,%mem,vsz,sgi_rss,tname,stat,start_time,time,ucmd
Putting it all together without the column headers it's much easier to deal with when scripting.
List of highest to lowest % CPU processes:
$ ps ax --no-headings -o user,pid,%cpu,%mem,vsz,sgi_rss,tname,stat,start_time,time,ucmd |sort -nrk 3|head -10
saml 18086 114 6.4 1418852 515236 ? Sl Aug27 1-10:53:31 chrome
saml 18536 14.7 4.1 1276240 328636 ? Sl Aug27 04:29:21 chrome
saml 18558 12.2 3.4 1209712 278228 ? Sl Aug27 03:44:22 chrome
saml 18543 10.9 3.8 1238132 308824 ? Rl Aug27 03:20:18 chrome
root 1764 7.7 0.4 170220 35276 tty1 Rs+ Aug21 13:40:16 Xorg
saml 18174 7.3 3.0 1167728 241728 ? Sl Aug27 02:14:25 chrome
saml 18314 3.6 1.4 1049020 119308 ? Sl Aug27 01:06:19 chrome
saml 18528 2.7 3.1 1178368 251212 ? Sl Aug27 00:50:55 chrome
saml 2389 2.0 0.1 330632 8480 ? Sl Aug21 03:37:13 compiz
saml 18208 1.7 1.3 1081132 108828 ? Sl Aug27 00:32:02 chrome
List of lowest to highest % CPU processes:
$ ps ax --no-headings -o user,pid,%cpu,%mem,vsz,sgi_rss,tname,stat,start_time,time,ucmd |sort -nk 3|tail -10
saml 18208 1.7 1.3 1082156 108348 ? Sl Aug27 00:32:03 chrome
saml 2389 2.0 0.1 330632 8492 ? Sl Aug21 03:37:15 compiz
saml 18528 2.7 3.1 1181440 250856 ? Sl Aug27 00:50:58 chrome
saml 18314 3.6 1.5 1050044 119828 ? Sl Aug27 01:06:25 chrome
saml 18174 7.3 3.0 1167728 242068 ? Sl Aug27 02:14:32 chrome
root 1764 7.7 0.3 163688 28716 tty1 Ss+ Aug21 13:40:26 Xorg
saml 18543 10.9 3.8 1235060 305464 ? Sl Aug27 03:20:32 chrome
saml 18558 12.2 3.5 1214832 283560 ? Sl Aug27 03:44:34 chrome
saml 18536 14.7 3.9 1267024 314400 ? Sl Aug27 04:29:39 chrome
saml 18086 114 6.4 1412992 514856 ? Sl Aug27 1-10:55:28 chrome
ps you'll have to craft a script - stackoverflow.com/a/34985996/33204.
If you are in Mac Ecosystem (like I am) all the other solutions will need a lot of additional work. Eg. --sort or other -- options are not supported by default as others mentioned above.
The best bet is the command below:
ps aux | awk '{print $1, $2, $3, $11}' | sort -n -k3 -r | head -n 10
This prints top 10 CPU consuming processes specifically: their user that started it, PID, CPU %age, and the command that started it.
ps has the -r flag to sort by CPU. I added answer: unix.stackexchange.com/a/734132/141153
Feb 2 at 22:59
On macOS, you can use the BSD-only -r flag to "sort by current CPU usage":
ps -aexro pcpu,cputime,pid,etime,user,args | head
There's also the -m flag to sort by "memory usage" (man ps doesn't say whether this is real or shared or private memory).
topinstead?awk. Afterwards, when you're ready to move things "to production", you should usetopin batch mode if it's suitable for your requirements.file.txtby doingps aux|cut -c ...