What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

Universal configuration monitoring and system of record for IT.

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:



May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

Top Tags





Commands tagged process from sorted by
Terminal - Commands tagged process - 38 results
pgrep -lf processname | cut -d' ' -f1 | awk '{print "cat /proc/" $1 "/net/sockstat | head -n1"}' | sh | cut -d' ' -f3 | paste -sd+ | bc
ps axo pid=,stat= | awk '$2~/^Z/ { print $1 }'
2014-11-26 21:29:33
User: krizzo
Functions: awk ps

This prints out a list of all zombie processes PIDs so you can do things like kill the zombies

/usr/bin/lynx -dump -width 500 | grep GET | awk '{print $12 $14}' | sort | uniq -c | sort -rn | head
2014-03-12 13:24:40
User: copocaneta
Functions: awk grep sort uniq

List the busiest scripts/files running on a cPanel server with domain showing (column $12).

nohup bash -c "while true; do ps -x | mail pascalv@mmmmail.com; sleep 3600; done" | mail pascalv@mmmmail.com &
2013-08-19 17:21:37
User: pascalv
Functions: bash mail nohup

Run "ps -x" (process status) in the background every hour (in this example).

The outputs of both "nohup" and "ps -x" are sent to the e-mail (instead of nohup.out and stdout and stderr).

If you like it, replace "ps -x" by the command of your choice, replace 3600 (1 hour) by the period of your choice.

You can run the command in the loop any time by killing the sleep process. For example

ps -x

2925 ? S 0:00.00 sh -c unzip E.zip >/dev/null 2>&1

11288 ? O 0:00.00 unzip E.zip

25428 ? I 0:00.00 sleep 3600

14346 pts/42- I 0:00.01 bash -c while true; do ps -x | mail pascalv; sleep 3600; done

643 pts/66 Ss 0:00.03 -bash

14124 pts/66 O+ 0:00.00 ps -x

kill 25428

You have mail in /mail/pascalv

python -c "a='$(ps -u luke | grep Viber.exe)';b= a.split(' ')[1];import os;os.system('cpulimit -l 1 -p '+b)"
sudo lsof -p `sudo ps aux | grep -i neo4j | grep -v grep | awk '{ print $2 }'`
2013-06-02 10:15:30
User: andycunn
Functions: awk grep ps sudo

Inner "ps...grep..." command searches for a process matching the specified .

"lsof -p lists all file descriptors owned by . Includes open files, sockets, devices, etc...

diffprocess () { diff <($*) <(sleep 3; $*); }
2013-01-25 08:46:41
User: totti
Functions: diff sleep

Execute a process or list of commands in the given interval and output the difference in output.

sudo nethogs eth0
ps -xaw -o state,ppid | grep Z | grep -v PID | awk '{ print $2 }' | xargs kill -9
2013-01-09 04:21:54
User: terrywang
Functions: awk grep kill ps xargs

Did some research and found the previous command wrong, we don't kill a zombie but its parent. Just made some modifcation to khashmeshab's command.

watch 'mysql -e "show full processlist;"'
top -p $(pgrep -d , foo)
top '-p' $(pgrep -d ' -p ' foo)
top $(pgrep foo | sed 's|^|-p |g')
2012-06-14 15:13:00
User: michelsberg
Functions: sed top
pgrep foo

may return several pids for process foobar footy01 etc. like this:




sed puts "-p " in front and we pass a list to top:

top -p 11427 -p 12576 -p 12577
TOTAL_RAM=`free | head -n 2 | tail -n 1 | awk '{ print $2 }'`; PROC_RSS=`ps axo rss,comm | grep [h]ttpd | awk '{ TOTAL += $1 } END { print TOTAL }'`; PROC_PCT=`echo "scale=4; ( $PROC_RSS/$TOTAL_RAM ) * 100" | bc`; echo "RAM Used by HTTP: $PROC_PCT%"
ps -ef --sort=-%cpu
echo $(($(ulimit -u)-$(pgrep -u $USER|wc -l))
kill -9 `ps xawo state=,pid=|sed -n 's/Z //p'`
2010-10-27 07:38:07
User: AskApache
Functions: kill sed

just a leaner, smaller version. Love the original idea!

kill -9 `ps -xaw -o state -o ppid | grep Z | grep -v PID | awk '{print $2}'`
2010-10-27 07:29:14
User: khashmeshab
Functions: awk grep kill

It identifies the parents of the Zombie processes and kill them. So the new parent of orphan Zombies will be the Init process and he is already waiting for reaping them. Be careful! It may also kill your useful processes just because they are not taking care and waiting for their children (bad parents!).

kill -9 `ps -xaw -o state -o pid | grep Z | grep -v PID | awk '{print $2}'`
2010-10-27 07:19:52
User: khashmeshab
Functions: awk grep kill

Tested on FreeBSD 8.1 and CSH. The scripts works correctly but the Zombies do not die! I hope it will run and function as expected in Linux and others.

cd /proc&&ps a -opid=|xargs -I+ sh -c '[[ $PPID -ne + ]]&&echo -e "\n[+]"&&tr -s "\000" " "<+/cmdline&&echo&&tr -s "\000\033" "\nE"<+/environ|sort'

Grabs the cmdline used to execute the process, and the environment that the process is being run under. This is much different than the 'env' command, which only lists the environment for the shell. This is very useful (to me at least) to debug various processes on my server. For example, this lets me see the environment that my apache, mysqld, bind, and other server processes have.

Here's a function I use:

aa_ps_all () { ( cd /proc && command ps -A -opid= | xargs -I'{}' sh -c 'test $PPID -ne {}&&test -r {}/cmdline&&echo -e "\n[{}]"&&tr -s "\000" " "<{}/cmdline&&echo&&tr -s "\000\033" "\nE"<{}/environ|sort&&cat {}/limits' ); }

From my .bash_profile at http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

wait $!
2010-06-07 21:56:36
User: noahspurrier
Functions: wait

Referring to the original post, if you are using $! then that means the process is a child of the current shell, so you can just use `wait $!`. If you are trying to wait for a process created outside of the current shell, then the loop on `kill -0 $PID` is good; although, you can't get the exit status of the process.

command ps wwo pid,user,group,vsize:8,size:8,sz:6,rss:6,pmem:7,pcpu:7,time:7,wchan,sched=,stat,flags,comm,args k -vsz -A|sed -u '/^ *PID/d;10q'

I've wanted this for a long time, finally just sat down and came up with it. This shows you the sorted output of ps in a pretty format perfect for cron or startup scripts. You can sort by changing the k -vsz to k -pmem for example to sort by memory instead.

If you want a function, here's one from my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

aa_top_ps(){ local T N=${1:-10};T=${2:-vsz}; ps wwo pid,user,group,vsize:8,size:8,sz:6,rss:6,pmem:7,pcpu:7,time:7,wchan,sched=,stat,flags,comm,args k -${T} -A|sed -u "/^ *PID/d;${N}q"; }
lsof | grep pcm
2010-05-16 12:12:01
User: Miles
Functions: grep

When trying to play a sound you may sometimes get an error saying that your sound card is already used, but not by what process. This will list all processes playing sound, useful to kill processes that you no longer need but that keep using your sound card.

echo $(( `ulimit -u` - `find /proc -maxdepth 1 \( -user $USER -o -group $GROUPNAME \) -type d|wc -l` ))
2010-03-12 08:42:49
User: AskApache
Functions: echo wc

There is a limit to how many processes you can run at the same time for each user, especially with web hosts. If the maximum # of processes for your user is 200, then the following sets OPTIMUM_P to 100.

OPTIMUM_P=$(( (`ulimit -u` - `find /proc -maxdepth 1 \( -user $USER -o -group $GROUPNAME \) -type d|wc -l`) / 2 ))

This is very useful in scripts because this is such a fast low-resource-intensive (compared to ps, who, lsof, etc) way to determine how many processes are currently running for whichever user. The number of currently running processes is subtracted from the high limit setup for the account (see limits.conf, pam, initscript).

An easy to understand example- this searches the current directory for shell scripts, and runs up to 100 'file' commands at the same time, greatly speeding up the command.

find . -type f | xargs -P $OPTIMUM_P -iFNAME file FNAME | sed -n '/shell script text/p'

I am using it in my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html especially for the xargs command. Xargs has a -P option that lets you specify how many processes to run at the same time. For instance if you have 1000 urls in a text file and wanted to download all of them fast with curl, you could download 100 at a time (check ps output on a separate [pt]ty for proof) like this:

cat url-list.txt | xargs -I '{}' -P $OPTIMUM_P curl -O '{}'

I like to do things as fast as possible on my servers. I have several types of servers and hosting environments, some with very restrictive jail shells with 20processes limit, some with 200, some with 8000, so for the jailed shells my xargs -P10 would kill my shell or dump core. Using the above I can set the -P value dynamically, so xargs always works, like this.

cat url-list.txt | xargs -I '{}' -P $OPTIMUM_P curl -O '{}'

If you were building a process-killer (very common for cheap hosting) this would also be handy.

Note that if you are only allowed 20 or so processes, you should just use -P1 with xargs.

for i in $(ps -ef | awk '{print $2}') ; { swp=$( awk '/Swap/{sum+=$2} END {print sum}' /proc/$i/smaps ); if [[ -n $swp && 0 != $swp ]] ; then echo -n "\n $swp $i "; cat /proc/$i/cmdline ; fi; } | sort -nr