Show All Running Processes in Linux

by nixCraft on October 12, 2006 · 97 comments· last updated at July 6, 2012

How do I see all running process in Linux?

You need to use the ps command. It provide information about the currently running processes, including their process identification numbers (PIDs). Both Linux and UNIX support ps command to display information about all running process. ps command gives a snapshot of the current processes. If you want a repetitive update of this status, use top command.

ps command

Type the following ps command to display all running process:
# ps aux | less
Where,

-A: select all processes
a: select all processes on a terminal, including those of other users
x: select processes without controlling ttys

Task: see every process on the system

# ps -A # ps -e

Task: See every process except those running as root

# ps -U root -u root -N

Task: See process run by user vivek

# ps -u vivek

Task: top command

The top program provides a dynamic real-time view of a running system. Type the top at command prompt:
# top
Output:

Fig.01: top command: Display Linux Tasks

To quit press q, for help press h.

Task: display a tree of processes

pstree shows running processes as a tree. The tree is rooted at either pid or init if pid is omitted. If a user name is specified, all process trees rooted at processes owned by that user are shown.
$ pstree
Sample outputs:

Fig.02: pstree - Display a tree of processes

Task: Print a process tree using ps

# ps -ejH # ps axjf

Task: Get info about threads

Type the following command:
# ps -eLf # ps axms

Task: Get security info

Type the following command:
# ps -eo euser,ruser,suser,fuser,f,comm,label # ps axZ # ps -eM

Task: Save Process Snapshot to a file

Type the following command:
# top -b -n1 > /tmp/process.log
Or you can email result to yourself:
# top -b -n1 | mail -s 'Process snapshot' you@example.com

Task: Lookup process

Use pgrep command. pgrep looks through the currently running processes and lists the process IDs which matches the selection criteria to screen. For example display firefox process id:
$ pgrep firefox
Sample outputs:

Following command will list the process called sshd which is owned by a user called root:
$ pgrep -u root sshd

Say hello to htop and atop

htop is interactive process viewer just like top, but allows to scroll the list vertically and horizontally to see all processes and their full command lines. Tasks related to processes (killing, renicing) can be done without entering their PIDs. To install htop type command:
# apt-get install htop
or
# yum install htop
Now type the htop command at the shell prompt:
# htop
Sample outputs:

Fig.03: htop - Interactive Linux / UNIX process viewer (click to enlarge)

atop program

The program atop is an interactive monitor to view the load on a Linux system. It shows the occupation of the most critical hardware resources (from a performance point of view) on system level, i.e. cpu, memory, disk and network. It also shows which processes are responsible for the indicated load with respect to cpu- and memory load on process level; disk- and network load is only shown per process if a kernel patch has been installed. Type the following command to start atop:
# atop
Sample outputs:

Featured Articles:

{ 97 comments… read them below or add one }

1 dom November 26, 2007 at 5:15 pm

i hope you dont mind, i have borrowed your image showing PS for my assigment, i have have referenced this site and the date

Dom

2 saurabh February 20, 2008 at 10:23 pm

No offense, but this is akin to posting instructions on how to walk.

3 blablabla May 30, 2010 at 1:54 am

You are a an elitest jerk. Interesting that for someone who believes he already knows everything, you are entirely ignorant of this fact. It is likely that no one was impressed by your comment except yourself.

4 Cytrax June 6, 2010 at 10:54 am

Don’t worry, he wrote his original lame comment back in 08. He’s probably less ignorant now.

Great article!

5 steve September 10, 2011 at 11:47 pm: The guy is an idot
Reply
6 cyberit January 23, 2013 at 12:14 am: ‘last updated at JULY 6, 2012′ or may be in 2008 it was! Btw – I have to still meet some one who was born walking.
Reply

7 jay March 7, 2008 at 1:38 am

@saurabh – I’m glad you think this is like posting instructions on how to walk. I’m also glad that you are such a naturally gifted user that you knew this without ever having to look up how to do this. Some of us have just started using Linux and guess what it is small little tid bits like this that help.

8 anya March 11, 2008 at 9:28 pm

Thanks a lot for the info. It proved really useful. Sometimes it helps when somebody tells you how to walk…

9 Maria March 26, 2008 at 10:31 am

It’s fantastic to know that a great community is behind it.

Thanks

10 Jamal May 15, 2008 at 6:19 pm

can someone tell me how to create a script that list all processes that are taking more than 10% of cpu time?

thanks

btw i am a noob lol

11 ddd July 6, 2008 at 11:11 pm

Great! Thanks

12 akinhowtowalk August 8, 2008 at 10:39 pm

@saurabh no offense, are you an Indian? If so, that explains and if not, set up your own site and don’t post anything on it loser.

Great stuff.

13 I'm a INDIAN September 14, 2010 at 7:40 pm: what the hell do u know about indian? shut the hell up and do some linux home work kiddo..
Reply
14 the london dude October 3, 2010 at 2:32 pm: @akinhowtowalk: i’m so glad you’ve demonstrated so much more maturity than saurabh through your sweeping generalization.
Reply
15 ritwik February 15, 2013 at 9:09 am: The guy who wrote the article is also indian. His name is Vivek
Reply

16 WebDesignKing September 8, 2008 at 2:42 pm

Lol @ akinhowtowalk. Well said!

Great resource

17 hkhk January 2, 2012 at 6:29 am

Hahah indians are the most dumb nation and yes smelly tooo :)

18 anky April 4, 2012 at 6:45 am: shut up man…mind ur tounge..wt u knw abt indians???
Reply

19 sarmad November 6, 2008 at 6:42 am

i want to know how can i run command that show me which script is currently running and by which user

20 Allimuthu December 25, 2008 at 7:27 pm

Hi Everybody, I got an cleared information in this site. But I want to know that what are the process currently active in my shell. If any body know, please email me @ allimut@gmail.com

Thanks,
-Allimuthu.

21 mellow_bunny January 14, 2009 at 10:29 pm

Yo thanks heaps for this info! It’s just what I needed! *favourited*

22 Greg January 29, 2009 at 6:21 pm

akinhowtowalk good answer for the loser :D

23 Ken February 8, 2009 at 9:25 pm

I’ve been walking the Linux path for a long time and it’s nice to see this type of command posted.

To see what is running and consuming resources you could use (exactly as it is shown):
ps -e -o pcpu,cpu,nice,state,cputime,args –sort pcpu | sed “/^ 0.0 /d”

which is nice to enter into the .bashrc in your home directory as an alias. Like this (on the last line after every other entry):
alias hog=’ps -e -o pcpu,cpu,nice,state,cputime,args –sort pcpu | sed “/^ 0.0 /d”‘

so the next time I log in I can just type hog at the command line and see all process running and consuming resources, sorted.

Ken

24 unokpasabaxaki February 16, 2009 at 8:51 pm

In the path of Linux, if you want to start running without knowing how to walk, what will happen? Begginers know that they can get to the top, but step by step. Otherwise, they’ll fall. And let’s stop the metaphores xD

25 vivek February 21, 2009 at 4:09 am

Hello

Any one help to find command history with date & time.

26 SleepWalker April 1, 2009 at 8:16 pm

Thank you. found it very useful :)
Lol@akinhowtowalk well said :)
Regards,
ILoveTakingHelp :P

27 the mad hatter May 18, 2009 at 2:49 pm

Thanks for posting this ! You’ve helped me a lot !

28 HomeHacker2 May 20, 2009 at 5:20 pm

thanks for that. i needed this to set something running and set-up on a linux server. but i needed to kill it first so :)thanks.

29 chinmay May 26, 2009 at 5:44 am

hello akinhowtowalk

i find this site really usefull and find the stuff what i was looking for…
and saurabh’s comment was not justified…
but what was ur comment on being an indian… i really didnt understood that…and y..
that explains wat..??

30 Jo June 24, 2009 at 5:55 am

Thanks for the htop info, really useful tool!!!

31 radutir July 12, 2009 at 2:57 pm

thx.
it’s nice
thx a lot for this tool

32 guy August 2, 2009 at 1:09 pm

Hey, can someone please give me instructions on how to walk?

33 stuck here August 7, 2009 at 6:33 am

Since I learnt how to use ps I forgot how to walk. Anyone know the neccessary commands?

34 PaNda August 19, 2009 at 1:08 am

Cool instruction, i dont know there were commands that named “TOP”

and…… i forget how to walk =( *(googling how to walk)

35 Ray_D August 25, 2009 at 6:57 pm

saurabh, were you born walking? Didn’t think so.

36 Cameron September 8, 2009 at 9:58 pm

saurabh takes baby steps as he is always half drunk

37 Chongopants September 24, 2009 at 7:17 pm

saurabh, stfu..

that is all you may go on with your sad life.

38 saurabh-is-a-retard October 24, 2009 at 9:43 am

saurabh:
how do you expect newbies to learn if people don’t post stuff like this?

39 kek October 27, 2009 at 12:42 am

netstat -tulnap

This command is usefull when you whant to know what process is responsible for each open port.

40 wat. November 18, 2009 at 10:21 am

I’m amazed that more then one and a half year after a person has posted a single message,
Chongopants 09.24.09 at 7:17 pm
saurabh, stfu..
that is all you may go on with your sad life.
something like this is still said

41 Nicolas Pinçon March 9, 2010 at 9:47 pm

very helpful page!! Thx a lot to whoever wrote it

42 verizon saga May 4, 2010 at 2:24 pm

thankz very much master ..

its a good post .. and very usefull for me :)

htop :D i was find for more times

43 abhishek May 19, 2010 at 7:21 pm

akinhowtowalk,

Don’t generalize, not all Indians are like saurabh. Grow up. Boasting exists irrespective of race.

44 Sumit June 2, 2010 at 7:02 am

@akinhowtowalk – I am really offended by your remarks on a specific nation. I dont expects mature guys to make such kind of remark. really very disappointing (i can also go dirty in reaction but i dont prefer to). Make sure you comment on individual and not on any group/society/nation.

@Saurabh – If you are an expert then i will appreciate you posting advance topics on linux and punlish the URL on this forum. If you cant do that much for community then you dont have any rights to comments on someones contribution.

45 ashish April 7, 2013 at 8:08 am: nice reply.
well put,
and well explained to both of our friends concerned.
And btw, This was an Awesome post! :)
Reply

46 Anonymous June 20, 2010 at 4:36 pm

i probably think saurab never came back to this page after he commented on it. You guys were so foolish enough to comment back . lol
I was just looking for something that can give me the green signal so that i can quit all running processes before i shut my computer…. And i ended up here. Looks i i still cant get what i should type to see only those processes that are running currently. Some thing like the task manager in windows . Any help with that ?

47 agree September 27, 2011 at 8:02 pm: Green Signal !
Please go ahead and reboot
Reply

48 luis June 22, 2010 at 4:21 am

Thanks =)

49 noufalcm July 19, 2010 at 12:31 pm

Hi
I wanted to display only PID and Process name in MAC OS. “ps” doesn’t display process name rather command only. Can Anyone help.
Thanx & regards in advance
Noufal

50 DaveUK September 12, 2010 at 3:09 pm

I am a complete newbie to linux and I *am* learning to walk with it,, so thanks for the article :)

51 AndyC September 30, 2010 at 6:18 am

akinhowtowalk probably said that regarding Indians coz he knows that Indians are smarter .. atleast they make our Business run smoothly ..cheers :)

52 Alex October 7, 2010 at 8:07 pm

Thanks. In an introduction to UNIX class, this helped out and quicker than looking it up in my textbook.

53 Muthukrishnan November 25, 2010 at 5:33 am

Very userful.. Thanks a lot…..!!

54 Pankaj December 24, 2010 at 5:41 pm

Nice….. got geat help…. Thanks…

55 Wayne March 28, 2011 at 1:08 pm

Great Site.
Well written articles.
And Just to keep it going…
Why walk when you can run with Linux!!

56 L.PRINCE RAJ April 5, 2011 at 2:10 am

I am using Fedora 14 in my laptop. I installed an .rpm file , but i don’t know how to run that software. please help me. I am new for Linux.

57 Wayne April 5, 2011 at 10:12 am: Well I think the first best question that needs to be asked is what software have you installed?
Reply

58 L.PRINCE RAJ April 5, 2011 at 12:10 pm

I installed an CFD software named as ‘ZNTutor-CFD-2.1.0-0.i386.rpm’. the installation is successful.

59 Wayne April 5, 2011 at 11:58 pm: As this is a commercial program I wont be installing it to have a look. I would suggest asking the question in a forum more related / dedicated to this product. Also have a look to find where the package was installed and read the manual that was supplied.
If this manual doesn’t even cover the simple processes I would be a little worried about it considering the subject matter involved.
Reply

60 L.PRINCE RAJ April 6, 2011 at 12:41 am

Ok I will try to get that..

61 soundarapandian April 6, 2011 at 7:28 am

Thanks very useful

62 gabe May 11, 2011 at 2:53 pm

Very useful keep going on!

63 Efim May 18, 2011 at 11:17 am

Very laconic and very good article
Thanks

64 NewToLinux June 7, 2011 at 9:56 pm

Thanks a lot Vivek for taking the time to post the help for these commands in a detailed manner!

65 jeff June 30, 2011 at 12:43 pm

Thanks for the help, I found the problem right off!

66 dizzy July 14, 2011 at 8:47 pm

Very useful, thanks!

67 kebiraj July 15, 2011 at 12:45 pm

hi,

i’m running one process in linux server with the common user that is using by 20 people from different windows machine, i want to know who executed the command at what time in the linux server? is there any file/log location that having all the commands that executed in the server.

Thanks in adv,
Kebiraj

68 n00b August 3, 2011 at 10:24 am

very useful commands, thanks to OP.

Thanks to everyone else for the amusing read lol

69 justme19 August 6, 2011 at 3:34 pm

Thanks a lot for this articles. I searched for one solution and found several in one page. God bless u Vivek for making some of us who are new and started to “walk” with Linux, and for those unjustified comments..well just ignored them.

70 sheril September 20, 2011 at 12:52 am

Thanks, Well explained.

71 sureshatt October 10, 2011 at 6:41 am

Great article. Thank you very much. And one thing to remember for all linuxholics, “Linux is for human being’s goodness” , sharing is the fuel that runs the community. Share everything even if you think it is less important, because there are many people who are looking for a point to startup. Knowing Linux means nothing if you don’t know the great philosophy behind it.
thanks,

72 Momo October 19, 2011 at 5:40 pm

Many thanks for posting those instructions.

73 Fred October 20, 2011 at 11:41 pm

Great work, very clear instruction. I’ve been using Linux for 2 years and still believe there’s a lot for me to learn or I should say to know. Pages like this makes a huge difference for learners who try and never give up. I really appreciate the time and efforts of the author, keep it up my friend. As for the guy with “walk” comment I’d like to say you don’t have to read what you don’t like, at least give this guy the credit for the time and effort for putting this together for the world and, go ahead and show the world what you’re ca[able of.

Fred

74 alvarobsp October 21, 2011 at 2:15 am

@saurobh: Successful troll is successful. lol

Really helpful post, thanks :)

75 shailendra November 15, 2011 at 3:48 am

thank u sir

76 Raghav November 22, 2011 at 11:06 am

Can any one tell me how can i list all the processes launched from a directory and sort them to find the process which is consuming more memory than others.
We are using AIX.
Please help me.

77 chapise November 24, 2011 at 1:26 am

thanks so much dude.., it really helps me, i’m new in linux

78 harsha December 13, 2011 at 6:58 pm

good work…thanks :)

79 meow December 16, 2011 at 12:53 am

Nice, thanks.

80 ash7 December 18, 2011 at 8:01 am

good post. quite useful.

81 encikkelantan January 4, 2012 at 1:00 am

hello,i wonder,how to know the details of user who run specific processes?

82 lanh January 8, 2012 at 7:47 am

Good stuff thx!

83 Shaza February 10, 2012 at 8:09 am

bkmraaster on November 6, 2011 Oh well why not give it a shot, there’s nothing to lose, so I guess there’s everything to win! And cmon who doesn’t like sony products!

84 ahmed March 14, 2012 at 6:57 pm

i love you

85 Rafael March 15, 2012 at 12:42 pm

Thanks for your article, help me a lot!

86 Edward Beckett July 6, 2012 at 6:28 am

This site’s one of the best resources for nix noobs … much prec

87 arif July 7, 2012 at 2:31 pm

i have run vacum but still the problem not yet solved

[root@onms-dr mysql]# /etc/init.d/opennms start
Starting OpenNMS: org.postgresql.util.PSQLException: FATAL: database is not accepting commands to avoid wraparound data loss in database “postgres”
OpenNMS runs better if you start up the database first.
[FAILED]

88 Satish September 17, 2012 at 1:40 pm

you can also view all the running process by running the below command

service –status-all

89 Ahsan September 28, 2012 at 8:06 am

Nice site… for noobs :)

90 Toppy October 5, 2012 at 5:43 am

I’ve just boomarked the website, it’s useful for my jobs.

91 Min Thu October 19, 2012 at 5:20 am

Thanks!

92 yash November 7, 2012 at 4:50 pm

how can I print the virtual pages allocated to the currently running processes on my system and also the page faults associated with them?

93 Alexis December 12, 2012 at 6:34 am

Yip years later this is still a useful page. Didn’t know about htop, quite like it.

I thought I saw a comment asking how to show processes for a user.
top -u root
or
htop -u root

94 Prateek December 19, 2012 at 4:03 am

great stuff and that htop thing was really useful

Thanks

95 Nikola January 8, 2013 at 5:10 am

Nice tut, i love htop, it’s very good :)

96 sunidhi March 15, 2013 at 11:10 am

hello everyone will u pls tell me use of sort -o cmd

97 Richard Blaine March 22, 2013 at 10:47 pm

Thank you much. The information might be dated, but still very relevant. Good Stuff.