Killing Linux Process by Piping the Id

Killing linux process by piping the id

Try the backtick operator for evaluating a sub-command

kill -s SIGINT `pgrep -f "python myscript.py"`

(untested)

How to give arguments to kill via pipe

kill $(ps -e | grep dmn | awk '{print $1}')

Kill process on the left side of a pipe

By killing the whole process group instead of just bash (the parent), you can send the kill signal to all children as well.
Syntax examples are:

kill -SIGTERM -$!
kill -- -$!

Example:

bash -c 'sleep 50 | sleep 40' & sleep 1; kill -SIGTERM -$!; wait; ps -ef | grep -c sleep
[1] 14683
[1]+  Terminated              bash -c 'sleep 50 | sleep 40'
1

Note that wait here waits for bash to be effectively killed which takes some milliseconds.
Also note that the final result (1) is the 'grep sleep' itself. A result of 3 would show that this did not work as two additional sleep processes would still be running.

The kill manual mentions:

-n
where n is larger than 1. All processes in process group n are signaled.
When an argument of the form '-n' is given, and it is meant to denote a
process group, either the signal must be specified first, or the argument
must be preceded by a '--' option, otherwise it will be taken as the signal
to send.

Shell script to capture Process ID and kill it if exist

Actually the easiest way to do that would be to pass kill arguments like below:

ps -ef | grep your_process_name | grep -v grep | awk '{print $2}' | xargs kill

Hope it helps.

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

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.

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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 :-)

How to kill a process running on particular port in Linux?

Use the command

 sudo netstat -plten |grep java

used grep java as tomcat uses java as their processes.

It will show the list of processes with port number and process id

tcp6       0      0 :::8080                 :::*                    LISTEN      
1000       30070621    16085/java

the number before /java is a process id. Now use kill command to kill the process

kill -9 16085

-9 implies the process will be killed forcefully.

How to kill all processes with a given partial name?

Use pkill -f, which matches the pattern for any part of the command line

pkill -f my_pattern

Just in case it doesn't work, try to use this one as well:

pkill -9 -f my_pattern

Kill process by pid file

I believe you are experiencing this because your default shell is dash (the debian almquist shell), but you are using bash syntax. You can specify bash in the shebang line with something like,

#!/usr/bin/env bash

Or, you could use the dash and bash compatible back-tick expression suggested by admdrew in the comments

kill -9 `cat /var/run/myProcess.pid`

Regardless, you can't rely on /bin/sh to be bash.

What's the best way to send a signal to all members of a process group?

You don't say if the tree you want to kill is a single process group. (This is often the case if the tree is the result of forking from a server start or a shell command line.) You can discover process groups using GNU ps as follows:

 ps x -o  "%p %r %y %x %c "

If it is a process group you want to kill, just use the kill(1) command but instead of giving it a process number, give it the negation of the group number. For example to kill every process in group 5112, use kill -TERM -- -5112.

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