Linux Basics Part25 Linux Process Management PS KILL NICE RENICE TOP
05 01 2022
PS - process
ps - report a snapshot of the current processes.
ps -e
-ef
-ax
-aux
-eo
ps --help
EXAMPLES
To see every process on the system using standard syntax:
ps -e
ps -ef
ps -eF
ps -ely
To see every process on the system using BSD syntax:
ps ax
ps axu
To print a process tree:
ps -ejH
ps axjf
To get info about threads:
ps -eLf
ps axms
To get security info:
ps -eo euser,ruser,suser,fuser,f,comm,label
ps axZ
ps -eM
To see every process running as root (real & effective ID) in
user format:
ps -U root -u root u
To see every process with a user-defined format:
ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm
ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm
ps -Ao pid,tt,user,fname,tmout,f,wchan
Print only the process IDs of syslogd:
ps -C syslogd -o pid=
Print only the name of PID 42:
ps -q 42 -o comm=
ps - process - cmd, pid, ppid, nice, uid
ps -eo user,pid,ni,cmd
stop / kill process
kill pid
ps -eo user,pid,ni,cmd
ps -eo user,pid,ni,cmd
kill 4505
ps -eo user,pid,ni,cmd
sleep 100 &
ps -eo user,pid,ni,cmd
ps -eo user,pid,ni,cmd | grep sleep
ps -eo user,pid,ni,cmd | grep NetworkManager
ps -eo user,pid,ni,cmd | grep sshd
sleep 1000 &
ps -eo user,pid,ni,cmd | grep sleep
kill 5462
ps -eo user,pid,ni,cmd | grep sleep
[root@cts9linuxcli ~]# kill -l
1- 1) SIGHUP
9- 9) SIGKILL
15- 15) SIGTERM
20- 20) SIGTSTP
sleep 100 &
[1] 5766
ps -eo user,pid,ni,cmd | grep sleep
root 5766 0 sleep 100
root 5776 0 grep --color=auto sleep
kill -9 5766
ps -eo user,pid,ni,cmd | grep sleep
root 5795 0 grep --color=auto sleep
[1]+ Killed sleep 100
sleep 100 &
[1] 5805
ps -eo user,pid,ni,cmd | grep sleep
root 5805 0 sleep 100
root 5809 0 grep --color=auto sleep
kill -15 5805
ps -eo user,pid,ni,cmd | grep sleep
root 5824 0 grep --color=auto sleep
[1]+ Terminated sleep 100
sleep 100 &
[1] 5837
ps -eo user,pid,ni,cmd | grep sleep
root 5837 0 sleep 100
root 5841 0 grep --color=auto sleep
kill 5837
ps -eo user,pid,ni,cmd | grep sleep
root 5859 0 grep --color=auto sleep
[1]+ Terminated sleep 100
sleep 100 &
[1] 5868
ps -eo user,pid,ni,cmd | grep sleep
root 5868 0 sleep 100
root 5878 0 grep --color=auto sleep
kill -20 5868
ps -eo user,pid,ni,cmd | grep sleep
root 5868 0 sleep 100
root 5892 0 grep --color=auto sleep
[1]+ Stopped sleep 100
kill -1 5868
ps -eo user,pid,ni,cmd | grep sleep
root 5868 0 sleep 100
root 5904 0 grep --color=auto sleep
---------------------------------------------------
nice - run a program with modified scheduling priority
Nice‐
ness values range from -20 (most favorable to the process) to 19
(least favorable to the process).
nice - -20 to 19
-20 - very high priority
10 -high
-5 - normal -high
0 - normal
5 - normal -low
10 - low
19 - very low priority
renice -n nicevalue pid
--change priority of running process
nice -n nicevalue process/cmd
--open a process with a priority
sleep 1000 &
[2] 6134
ps -eo user,pid,ni,cmd | grep sleep
root 5868 0 sleep 100
root 6134 0 sleep 1000
root 6138 0 grep --color=auto sleep
renice -10 6134
6134 (process ID) old priority 0, new priority -10
ps -eo user,pid,ni,cmd | grep sleep
root 5868 0 sleep 100
root 6134 -10 sleep 1000
root 6163 0 grep --color=auto sleep
renice -n 10 6134
6134 (process ID) old priority -10, new priority 10
ps -eo user,pid,ni,cmd | grep sleep
root 5868 0 sleep 100
root 6134 10 sleep 1000
root 6183 0 grep --color=auto sleep
nice -n -10 sleep 2000 &
ps -eo user,pid,ni,cmd | grep sleep
root 5868 0 sleep 100
root 6134 10 sleep 1000
root 6295 -10 sleep 2000
root 6320 0 grep --color=auto sleep
nice -n 5 sleep 3000 &
[5] 6339
ps -eo user,pid,ni,cmd | grep sleep
root 5868 0 sleep 100
root 6134 10 sleep 1000
root 6295 -10 sleep 2000
root 6339 5 sleep 3000
root 6342 0 grep --color=auto sleep
-----------------------------------------------
TOP
top - display Linux processes
currently running -- like task manager
top
k -- kill process
k pid 9/15
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