Linux process status using command line tools
by Mallikarjun
Overview
- List all processes in system
- List processes by users
- List process tree
- Process status Wrap output
- Show process thread information
- Search processes by command
- Search process by pid and output memory and cpu
- Search process by pid and output memory and cpu in repeated interval
- Sort processes by memory, cpu
- Processess view using Top command
- References
List all processes in system
This command lists all processes currently running in system
➜ ps -eF
UID PID PPID C SZ RSS PSR STIME TTY TIME CMD
root 1 0 0 29957 5916 6 Aug14 ? 00:00:03 /sbin/init splash
root 2 0 0 0 0 5 Aug14 ? 00:00:00 [kthreadd]
root 3 2 0 0 0 0 Aug14 ? 00:00:01 [ksoftirqd/0]
root 5 2 0 0 0 0 Aug14 ? 00:00:00 [kworker/0:0H]
root 7 2 0 0 0 0 Aug14 ? 00:00:38 [rcu_sched]
root 8 2 0 0 0 0 Aug14 ? 00:00:00 [rcu_bh]
root 9 2 0 0 0 0 Aug14 ? 00:00:02 [migration/0]
root 10 2 0 0 0 0 Aug14 ? 00:00:00 [watchdog/0]
root 11 2 0 0 0 1 Aug14 ? 00:00:00 [watchdog/1]
» ps is a command line utility to report a snapshot of current processes.
» -e selects all processes
List processes by users
This command lists the processes filtered by set of user
➜ ps -F -u root,syslog
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 Aug14 ? 00:00:03 /sbin/init splash
root 2 0 0 Aug14 ? 00:00:00 [kthreadd]
root 3 2 0 Aug14 ? 00:00:00 [ksoftirqd/0]
root 5 2 0 Aug14 ? 00:00:00 [kworker/0:0H]
root 7 2 0 Aug14 ? 00:00:24 [rcu_sched]
root 8 2 0 Aug14 ? 00:00:00 [rcu_bh]
root 9 2 0 Aug14 ? 00:00:01 [migration/0]
syslog 921 1 0 Aug14 ? 00:00:00 /usr/sbin/rsyslogd -n
» -f to display more information about the processes
» -u to display the processes of set of users
List process tree
Lists all processes in tree format
➜ ps -ef --forest
UID PID PPID C STIME TTY TIME CMD
root 2 0 0 Nov08 ? 00:00:00 [kthreadd]
root 3 2 0 Nov08 ? 00:00:06 \_ [ksoftirqd/0]
root 5 2 0 Nov08 ? 00:00:00 \_ [kworker/0:0H]
root 7 2 0 Nov08 ? 00:00:57 \_ [rcu_sched]
root 27466 1 0 11:02 ? 00:00:00 nginx: master process /usr/sbin/nginx -g daemon on; master_process on;
www-data 27467 27466 0 11:02 ? 00:00:00 \_ nginx: worker process
www-data 27468 27466 0 11:02 ? 00:00:00 \_ nginx: worker process
www-data 27469 27466 0 11:02 ? 00:00:00 \_ nginx: worker process
www-data 27474 27466 0 11:02 ? 00:00:00 \_ nginx: worker process
Lists single process in tree format.
ps --forest $(ps -e --no-header -o pid,ppid|awk -vp=<PID> 'function r(s){print s;s=a[s];while(s){sub(",","",s);t=s;sub(",.*","",t);sub("[0-9]+","",s);r(t)}}{a[$2]=a[$2]","$1}END{r(p)}')
PID TTY STAT TIME COMMAND
27466 ? Ss 0:00 nginx: master process /usr/sbin/nginx -g daemon on; master_process on;
27467 ? S 0:00 \_ nginx: worker process
27468 ? S 0:00 \_ nginx: worker process
27469 ? S 0:00 \_ nginx: worker process
27470 ? S 0:00 \_ nginx: worker process
27471 ? S 0:00 \_ nginx: worker process
27472 ? S 0:00 \_ nginx: worker process
27473 ? S 0:00 \_ nginx: worker process
27474 ? S 0:00 \_ nginx: worker process
➜ pstree -p 27466
nginx(27466)─┬─nginx(27467)
├─nginx(27468)
├─nginx(27469)
├─nginx(27470)
├─nginx(27473)
└─nginx(27474)
» --forest display the output in tree format
» --no-header to hide headers from ps output
» -o args arguments to be displayed in ps output. Refer man pages for details
Process status Wrap output
This does not truncate the process status output full command
➜ ps -ef ww
nobody 6577 1009 0 Nov08 ? S 0:01 /usr/sbin/dnsmasq --no-resolv --keep-in-foreground --no-hosts --bind-interfaces --pid-file=/var/run/NetworkManager/dnsmasq.pid --listen-address=127.0.1.1 --cache-size=0 --conf-file=/dev/null --proxy-dnssec --enable-dbus=org.freedesktop.NetworkManager.dnsmasq --conf-dir=/etc/NetworkManager/dnsmasq.d
» ww use this to set unlimited width. Or set -w width to set limited width
Show process thread information
This shows threads as processes with entry for each thread. NLWP - number of threads, LWP - light weight process (thread) ID
ps -f -p 10064 H -L
UID PID PPID LWP C NLWP STIME TTY STAT TIME CMD
nobody 10064 9921 10064 0 13 Nov09 ? Sl 3:00 /opt/google/chrome/chrome
nobody 10064 9921 10069 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10071 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10072 0 13 Nov09 ? Sl 0:18 /opt/google/chrome/chrome
nobody 10064 9921 10075 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10076 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10079 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10085 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10086 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10087 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10088 0 13 Nov09 ? Sl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 10089 0 13 Nov09 ? SNl 0:00 /opt/google/chrome/chrome
nobody 10064 9921 27031 0 13 14:31 ? Sl 0:00 /opt/google/chrome/chrome
» H Show threads as if they were processes.
» -L Show threads, possibly with LWP and NLWP columns.
Print thread count for a particular process
➜ ps -o nlwp -p 10064
NLWP
14
Search processes by command
➜ ps -f -C chrome
UID PID PPID C STIME TTY TIME CMD
nobody 9904 4687 1 Nov09 ? 00:40:02 /opt/google/chrome/chrome
nobody 9916 9904 0 Nov09 ? 00:00:00 /opt/google/chrome/chrome --type=zygote
nobody 9921 9916 0 Nov09 ? 00:00:01 /opt/google/chrome/chrome --type=zygote
nobody 10064 9921 0 Nov09 ? 00:05:08 /opt/google/chrome/chrome
nobody 10112 9921 1 Nov09 ? 00:46:04 /opt/google/chrome/chrome
nobody 10359 9921 0 Nov09 ? 00:00:47 /opt/google/chrome/chrome
nobody 10364 9921 0 Nov09 ? 00:06:22 /opt/google/chrome/chrome
» -C filter by command
Search process by pid and output memory cpu and threads
➜ ps -p 1113 -o pid,ppid,%mem,%cpu,nlwp,lwp
PID PPID %MEM %CPU NLWP LWP
1113 6054 1.2 0.6 47 1113
Search process by pid and output memory and cpu in repeated interval
➜ watch -n 1 'ps -p 1113 -o pid,ppid,%mem,%cpu'
Output:
Every 1.0s: ps -p 1113 -o pid,ppid,%mem,%cpu
PID PPID %MEM %CPU
1113 6054 1.2 0.6
» watch execute a program periodically, showing output fullscreen
» -n Specify update interval
Sort processes by memory, cpu
Sort all the commands with increasing cpu usage followed by memory
➜ ps -e u --sort=-%cpu,-%mem | head -5
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
nobody 10112 1.3 6.1 2366864 1004212 ? Sl Nov09 46:32 /opt/google/chrome/chrome
nobody 9904 1.2 2.4 1536920 406280 ? SLl Nov09 40:27 /opt/google/chrome/chrome
nobody 6712 0.9 0.7 1506472 118064 ? Ssl Nov08 40:23 compiz
root 1313 0.9 0.5 1028880 89484 tty7 Ssl+ Nov08 38:42 /usr/lib/xorg/Xorg -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
» --sort sort by specified columns
» (+/-) + numerically increasing, - numerically decreasing
» u Display user-oriented format
Processess view using Top command
Top command useful shortcuts
» M sort by memory usage
» P sort by cpu usage
» s change the refresh interval. Default 3.0 seconds
» m display memory in different display formats
» E display memory in different units (KB, MB, GB, etc).
» c toggle command arguments on/off
» 1 toggle processor level cpu usage on/off
» i toggle idle processos on/off
» H toggle between threads and tasks modes
» V toggle between forest/process tree and normal views
» o Filter by