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 the ps command to display information about all running process. The ps command gives a snapshot of the current processes. If you want a repetitive update of this status, use top, atop, and/or htop command as described below.
| Tutorial details | |
|---|---|
| Difficulty | Easy (rss) |
| Root privileges | Yes |
| Requirements | ps/top/htop |
| Estimated completion time | 5 minutes |
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:
3356
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:
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{ 97 comments… read them below or add one }
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
No offense, but this is akin to posting instructions on how to walk.
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.
Don’t worry, he wrote his original lame comment back in 08. He’s probably less ignorant now.
Great article!
The guy is an idot
‘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.
@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.
Thanks a lot for the info. It proved really useful. Sometimes it helps when somebody tells you how to walk…
It’s fantastic to know that a great community is behind it.
Thanks
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
Great! Thanks
@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.
what the hell do u know about indian? shut the hell up and do some linux home work kiddo..
@akinhowtowalk: i’m so glad you’ve demonstrated so much more maturity than saurabh through your sweeping generalization.
The guy who wrote the article is also indian. His name is Vivek
Lol @ akinhowtowalk. Well said!
Great resource
Hahah indians are the most dumb nation and yes smelly tooo :)
shut up man…mind ur tounge..wt u knw abt indians???
i want to know how can i run command that show me which script is currently running and by which user
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.
Yo thanks heaps for this info! It’s just what I needed! *favourited*
akinhowtowalk good answer for the loser :D
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
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
Hello
Any one help to find command history with date & time.
Thank you. found it very useful :)
Lol@akinhowtowalk well said :)
Regards,
ILoveTakingHelp :P
Thanks for posting this ! You’ve helped me a lot !
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.
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..??
Thanks for the htop info, really useful tool!!!
thx.
it’s nice
thx a lot for this tool
Hey, can someone please give me instructions on how to walk?
Since I learnt how to use ps I forgot how to walk. Anyone know the neccessary commands?
Cool instruction, i dont know there were commands that named “TOP”
and…… i forget how to walk =( *(googling how to walk)
saurabh, were you born walking? Didn’t think so.
saurabh takes baby steps as he is always half drunk
saurabh, stfu..
that is all you may go on with your sad life.
saurabh:
how do you expect newbies to learn if people don’t post stuff like this?
netstat -tulnap
This command is usefull when you whant to know what process is responsible for each open port.
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
very helpful page!! Thx a lot to whoever wrote it
thankz very much master ..
its a good post .. and very usefull for me :)
htop :D i was find for more times
akinhowtowalk,
Don’t generalize, not all Indians are like saurabh. Grow up. Boasting exists irrespective of race.
@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.
nice reply.
well put,
and well explained to both of our friends concerned.
And btw, This was an Awesome post! :)
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 ?
Green Signal !
Please go ahead and reboot
Thanks =)
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
I am a complete newbie to linux and I *am* learning to walk with it,, so thanks for the article :)
akinhowtowalk probably said that regarding Indians coz he knows that Indians are smarter .. atleast they make our Business run smoothly ..cheers :)
Thanks. In an introduction to UNIX class, this helped out and quicker than looking it up in my textbook.
Very userful.. Thanks a lot…..!!
Nice….. got geat help…. Thanks…
Great Site.
Well written articles.
And Just to keep it going…
Why walk when you can run with Linux!!
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.
Well I think the first best question that needs to be asked is what software have you installed?
I installed an CFD software named as ‘ZNTutor-CFD-2.1.0-0.i386.rpm’. the installation is successful.
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.
Ok I will try to get that..
Thanks very useful
Very useful keep going on!
Very laconic and very good article
Thanks
Thanks a lot Vivek for taking the time to post the help for these commands in a detailed manner!
Thanks for the help, I found the problem right off!
Very useful, thanks!
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
very useful commands, thanks to OP.
Thanks to everyone else for the amusing read lol
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.
Thanks, Well explained.
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,
Many thanks for posting those instructions.
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
@saurobh: Successful troll is successful. lol
Really helpful post, thanks :)
thank u sir
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.
thanks so much dude.., it really helps me, i’m new in linux
good work…thanks :)
Nice, thanks.
good post. quite useful.
hello,i wonder,how to know the details of user who run specific processes?
Good stuff thx!
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!
i love you
Thanks for your article, help me a lot!
This site’s one of the best resources for nix noobs … much prec
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]
you can also view all the running process by running the below command
service –status-all
Nice site… for noobs :)
I’ve just boomarked the website, it’s useful for my jobs.
Thanks!
how can I print the virtual pages allocated to the currently running processes on my system and also the page faults associated with them?
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
great stuff and that htop thing was really useful
Thanks
Nice tut, i love htop, it’s very good :)
hello everyone will u pls tell me use of sort -o cmd
Thank you much. The information might be dated, but still very relevant. Good Stuff.