Find and kill a process in one line using bash and regex

Question

I often need to kill a process during programming.

The way I do it now is:

[~]$ ps aux | grep 'python csp_build.py'
user    5124  1.0  0.3 214588 13852 pts/4    Sl+  11:19   0:00 python csp_build.py
user    5373  0.0  0.0   8096   960 pts/6    S+   11:20   0:00 grep python csp_build.py
[~]$ kill 5124

How can I extract the process id automatically and kill it in the same line?

Like this:

[~]$ ps aux | grep 'python csp_build.py' | kill <regex that returns the pid>

Answer 1

In bash, you should be able to do:

kill $(ps aux | grep '[p]ython csp_build.py' | awk '{print $2}')

Details on its workings are as follows:

• The ps gives you the list of all the processes.
• The grep filters that based on your search string, [p] is a trick to stop you picking up the actual grep process itself.
• The awk just gives you the second field of each line, which is the PID.
• The $(x) construct means to execute x then take its output and put it on the command line. The output of that ps pipeline inside that construct above is the list of process IDs so you end up with a command like kill 1234 1122 7654.

Here's a transcript showing it in action:

pax> sleep 3600 &
[1] 2225
pax> sleep 3600 &
[2] 2226
pax> sleep 3600 &
[3] 2227
pax> sleep 3600 &
[4] 2228
pax> sleep 3600 &
[5] 2229
pax> kill $(ps aux | grep '[s]leep' | awk '{print $2}')
[5]+  Terminated              sleep 3600
[1]   Terminated              sleep 3600
[2]   Terminated              sleep 3600
[3]-  Terminated              sleep 3600
[4]+  Terminated              sleep 3600

and you can see it terminating all the sleepers.

---

Explaining the grep '[p]ython csp_build.py' bit in a bit more detail:

When you do sleep 3600 & followed by ps -ef | grep sleep, you tend to get two processes with sleep in it, the sleep 3600 and the grep sleep (because they both have sleep in them, that's not rocket science).

However, ps -ef | grep '[s]leep' won't create a process with sleep in it, it instead creates grep '[s]leep' and here's the tricky bit: the grep doesn't find it because it's looking for the regular expression "any character from the character class [s] (which is s) followed by leep.

In other words, it's looking for sleep but the grep process is grep '[s]leep' which doesn't have sleep in it.

When I was shown this (by someone here on SO), I immediately started using it because

• it's one less process than adding | grep -v grep; and
• it's elegant and sneaky, a rare combination :-)

Answer 2

if you have pkill,

pkill -f csp_build.py

If you only want to grep against the process name (instead of the full argument list) then leave off -f.

Answer 3

One liner:

ps aux | grep -i csp_build | awk '{print $2}' | xargs sudo kill -9

• Print out column 2: awk '{print $2}'
• sudo is optional
• Run kill -9 5124, kill -9 5373 etc (kill -15 is more graceful but slightly slower)

---

Bonus:

I also have 2 shortcut functions defined in my .bash_profile (~/.bash_profile is for osx, you have to see what works for your *nix machine).

1. p keyword
   • lists out all Processes containing keyword
   • usage e.g: p csp_build , p python etc

bash_profile code:

# FIND PROCESS
function p(){
        ps aux | grep -i $1 | grep -v grep
}

2. ka keyword
   • Kills All processes that have this keyword
   • usage e.g: ka csp_build , ka python etc
   • optional kill level e.g: ka csp_build 15, ka python 9

bash_profile code:

# KILL ALL
function ka(){

    cnt=$( p $1 | wc -l)  # total count of processes found
    klevel=${2:-15}       # kill level, defaults to 15 if argument 2 is empty

    echo -e "\nSearching for '$1' -- Found" $cnt "Running Processes .. "
    p $1

    echo -e '\nTerminating' $cnt 'processes .. '

    ps aux  |  grep -i $1 |  grep -v grep   | awk '{print $2}' | xargs sudo kill -klevel
    echo -e "Done!\n"

    echo "Running search again:"
    p "$1"
    echo -e "\n"
}

Answer 4

killall -r regexp

-r, --regexp

Interpret process name pattern as an extended regular expression.

Answer 5

Try using

ps aux | grep 'python csp_build.py' | head -1 | cut -d " " -f 2 | xargs kill

Answer 6

This will return the pid only

pgrep -f 'process_name'

So to kill any process in one line:

kill -9 $(pgrep -f 'process_name')

or, if you know the exact name of the process you can also try pidof:

kill -9 $(pidof 'process_name')

But, if you do not know the exact name of the process, pgrep would be better.

If there is multiple process running with the same name, and you want to kill the first one then:

kill -9 $(pgrep -f 'process_name' | head -1)

Also to note that, if you are worried about case sensitivity then you can add -i option just like in grep. For example:

kill -9 $(pgrep -fi chrome)

More info about signals and pgrep at man 7 signal or man signal and man pgrep

Answer 7

You may use only pkill '^python*' for regex process killing.

If you want to see what you gonna kill or find before killing just use pgrep -l '^python*' where -l outputs also name of the process. If you don't want to use pkill, use just:

pgrep '^python*' | xargs kill

Answer 8

Use pgrep - available on many platforms:

kill -9 `pgrep -f cps_build`

pgrep -f will return all PIDs with coincidence "cps_build"

Answer 9

you can do it with awk and backtics

ps auxf |grep 'python csp_build.py'|`awk '{ print "kill " $2 }'`

$2 in awk prints column 2, and the backtics runs the statement that's printed.

But a much cleaner solution would be for the python process to store it's process id in /var/run and then you can simply read that file and kill it.

Answer 10

My task was kill everything matching regexp that is placed in specific directory (after selenium tests not everything got stop). This worked for me:

for i in `ps aux | egrep "firefox|chrome|selenium|opera"|grep "/home/dir1/dir2"|awk '{print $2}'|uniq`; do kill $i; done

Answer 11

To kill process by keyword midori, for example:

kill -SIGTERM $(pgrep -i midori)

Answer 12

ps -o uid,pid,cmd|awk '{if($1=="username" && $3=="your command") print $2}'|xargs kill -15

Answer 13

The solution would be filtering the processes with exact pattern , parse the pid, and construct an argument list for executing kill processes:

ps -ef  | grep -e <serviceNameA> -e <serviceNameB> -e <serviceNameC> |
awk '{print $2}' | xargs sudo kill -9

Explanation from documenation:

ps utility displays a header line, followed by lines containing information about all of your processes that have controlling terminals.

-e Display information about other users' processes, including those

-f Display the uid, pid, parent pid, recent CPU usage, process start

The grep utility searches any given input files, selecting lines that

-e pattern, --regexp=pattern Specify a pattern used during the search of the input: an input line is selected if it matches any of the specified patterns. This option is most useful when multiple -e options are used to specify multiple patterns, or when a pattern begins with a dash (`-').

xargs - construct argument list(s) and execute utility

kill - terminate or signal a process

number 9 signal - KILL (non-catchable, non-ignorable kill)

Example:

ps -ef  | grep -e node -e loggerUploadService.sh -e applicationService.js |
awk '{print $2}' | xargs sudo kill -9

Answer 14

A method using only awk (and ps):

ps aux | awk '$11" "$12 == "python csp_build.py" { system("kill " $2) }'

By using string equality testing I prevent matching this process itself.

Answer 15

Give -f to pkill

pkill -f /usr/local/bin/fritzcap.py

exact path of .py file is

# ps ax | grep fritzcap.py
 3076 pts/1    Sl     0:00 python -u /usr/local/bin/fritzcap.py -c -d -m

Answer 16

I started using something like this:

kill $(pgrep 'python csp_build.py')

Answer 17

Kill our own processes started from a common PPID is quite frequently, pkill associated to the –P flag is a winner for me. Using @ghostdog74 example :

# sleep 30 &                                                                                                      
[1] 68849
# sleep 30 &
[2] 68879
# sleep 30 &
[3] 68897
# sleep 30 &
[4] 68900
# pkill -P $$                                                                                                         
[1]   Terminated              sleep 30
[2]   Terminated              sleep 30
[3]-  Terminated              sleep 30
[4]+  Terminated              sleep 30

Answer 18

You don't need the user switch for ps.

kill `ps ax | grep 'python csp_build.py' | awk '{print $1}'`

Answer 19

In some cases, I'd like kill processes simutaneously like this way:

➜  ~  sleep 1000 &
[1] 25410
➜  ~  sleep 1000 &
[2] 25415
➜  ~  sleep 1000 &
[3] 25421
➜  ~  pidof sleep
25421 25415 25410
➜  ~  kill `pidof sleep`
[2]  - 25415 terminated  sleep 1000                                                             
[1]  - 25410 terminated  sleep 1000
[3]  + 25421 terminated  sleep 1000

But, I think it is a little bit inappropriate in your case.(May be there are running python a, python b, python x...in the background.)

Answer 20

If pkill -f csp_build.py doesn't kill the process you can add -9 to send a kill signall which will not be ignored. i.e. pkill -9 -f csp_build.py

Answer 21

I use this to kill Firefox when it's being script slammed and cpu bashing :) Replace 'Firefox' with the app you want to die. I'm on the Bash shell - OS X 10.9.3 Darwin.

kill -Hup $(ps ux | grep Firefox | awk 'NR == 1 {next} {print $2}' | uniq | sort)

Answer 22

I use gkill processname, where gkill is the following script:

cnt=`ps aux|grep $1| grep -v "grep" -c`
if [ "$cnt" -gt 0 ]
then
    echo "Found $cnt processes - killing them"
    ps aux|grep $1| grep -v "grep"| awk '{print $2}'| xargs kill
else
    echo "No processes found"
fi

NOTE: it will NOT kill processes that have "grep" in their command lines.

Answer 23

Using -C flag of ps command

-C cmdlist
     Select by command name.  This selects the processes whose
     executable name is given in cmdlist.

1st case, simple command

So if you run your script by standard shebang and calling them by his name:

/path/to/csp_build.py

You may find them whith

ps -C csp_build.py

So

kill $(ps -C csp_build.py ho pid)

may be enough.

2nd case, search for cmd

A little more strong, but still a lot quicker than most other answer in this SO question...

If you don't know ho this is run, or if you run them by

python csp_build.py
python3 csp_build.py
python /path/to/csp_build.py

You may find them by running:

ps -C python,python3,csp_build.py who pid,cmd | grep csp_build.py

Then using sed:

kill $(ps -C python,python3,csp_build.py who pid,cmd |
    sed -ne '/csp_build.py/s/^ *\([0-9]\+\) .*$/\1/p')

Answer 24

The following command will come handy:

kill $(ps -elf | grep <process_regex>| awk {'print $4'})

eg., ps -elf | grep top

    0 T ubuntu    6558  6535  0  80   0 -  4001 signal 11:32 pts/1    00:00:00 top
    0 S ubuntu    6562  6535  0  80   0 -  2939 pipe_w 11:33 pts/1    00:00:00 grep --color=auto top

kill -$(ps -elf | grep top| awk {'print $4'})

    -bash: kill: (6572) - No such process
    [1]+  Killed                  top

If the process is still stuck, use "-9" extension to hardkill, as follows:

kill -9 $(ps -elf | grep top| awk {'print $4'})

Hope that helps...!

Answer 25

Find and kill all the processes in one line in bash.

kill -9 $(ps -ef | grep '<exe_name>' | grep -v 'grep' | awk {'print $2'})

• ps -ef | grep '<exe_name>' - Gives the list of running process details (uname, pid, etc ) which matches the pattern. Output list includes this grep command also which searches it. Now for killing we need to ignore this grep command process.
• ps -ef | grep '<exec_name>' | grep -v 'grep' - Adding another grep with -v 'grep' removes the current grep process.
• Then using awk get the process id alone.
• Then keep this command inside $(...) and pass it to kill command, to kill all process.

Answer 26

You can use below command to list pid of the command. Use top or better use htop to view all process in linux. Here I want to kill a process named

ps -ef | grep '/usr/lib/something somelocation/some_process.js'  | grep -v grep | awk '{print $2}'

And verify the pid. It must be proper.To kill them use kill command.

sudo kill -9 `ps -ef | grep '/usr/lib/something somelocation/some_process.js'  | grep -v grep | awk '{print $2}'`

Eg:- is from htop process list.

sudo kill -9 `ps -ef | grep '<process>'  | grep -v grep | awk '{print $2}'`

This resolves my issues. Always be prepared to restart process if you accidentally kill a process.