Why does my kill .sh script sometimes not kill the intended processes? - linux

I have a .sh script that calls a number of other .sh scripts and tee's them into log files, and runs them in the background:
startMyProg.sh:
#!/bin/bash
./MyProg1.sh | tee /path/to/log/prog1_`date +\%Y\%m\%d_\%H\%M\%S`.log &
./MyProg2.sh | tee /path/to/log/prog2_`date +\%Y\%m\%d_\%H\%M\%S`.log &
./MyProgN.sh | tee /path/to/log/progN_`date +\%Y\%m\%d_\%H\%M\%S`.log &
I also have a simple helper script that will kill all the processes with MyProg in the name:
killMyProgs.sh:
#!/bin/bash
kill $(ps aux | grep MyProg | awk '{print $2}')
This system generally works, but occasionally the killMyProg.sh script doesn't kill the processes that it finds using the ps|grep|awk pattern. The part that really throws me for a loop is, when I face an instance where the .sh script doesn't kill the processes, I can call kill $(ps aux | grep MyProg | awk '{print $2}') directly from the command line and it will do what I expect it to! Is there something that I'm missing in my approach? Are there any useful debugging techniques that can help me figure out why my .sh script doesn't kill the processes but calling the exact command from the command line does?
A couple of details that may be relevant:
the "./MyProgN" scripts are calls to to start the same MyProg.jar file with different inputs. So the ps|grep of "MyProg" shows both the .sh scripts AND the java applications that they started and kills all of them.
Using RHEL7

Test few time to run:
ps aux | grep MyProg | awk '{print $2}'
You will notice that sometimes the grep command comes before MyProg
And sometimes grep command comes after MyProg (depnding on the pid).
Because grep command is listed as well in ps aux.
Therefore sometimes your script is killing the first grep command instead of your command.
The easiest solution is to use pkill command.
pkill -9 -f MyProg

Related

how to use kill command only with files name without PID

I wanna kill programs with one command
ps -elf | grep "common_program_name" | grep -v grep | awk '{print $2}' | xargs kill -9
but I got an error
kill: failed to parse argument: 'S
what am I doing wrong ?
Use killall -9 common_program_name
the problem above is that you might have more than one instance of the program running.
Also, you are fetching the second column from the output of ps That column does not contain a PID, so your xargs command effectively runs kill -9 S Perhaps you can adjust your flags to ps or your field captured by awk to make the above work, but there are already purpose built programs which do this job.
Use pkill, in your case pkill -9 common_program_name (for more see man pkill) which gives you the functionality you're looking for. And unlike killall won't kill literally all process on System V UNIX machines. ;)

how can I kill a process in a shell script

My bash script has:
ps aux | grep foo.jar | grep -v grep | awk '{print $2}' | xargs kill
However, I get the following when running:
usage: kill [ -s signal | -p ] [ -a ] pid ...
kill -l [ signal ]
Any ideas, how to fix this line?
In general, your command is correct. If a foo.jar process is running, its PID will be passed to kill and (should) terminate.
Since you're getting kill's usage as output, it means you're actually calling kill with no arguments (try just running kill on its own, you'll see the same message). That means that there's no output in the pipeline actually reaching xargs, which in turn means foo.jar is not running.
Try running ps aux | grep foo.jar | grep -v grep and see if you're actually seeing results.
As much as you may enjoy a half dozen pipes in your commands, you may want to look at the pkill command!
DESCRIPTION
The pkill command searches the process table on the running system and signals all processes that match the criteria
given on the command line.
i.e.
pkill foo.jar
Untested and a guess at best (be careful)
kill -9 $(ps -aux | grep foo.jar | grep -v grep | awk '{print $2}')
I re-iterate UNTESTED as I'm not at work and have no access to putty or Unix.
My theory is to send the kill -9 command and get the process id from a sub shell command call.

Awk not working inside bash script

Im trying to write a bash script and trying to take input from user and executing a kill command to stop a specific tomcat.
...
read user_input
if [ "$user_input" = "2" ]
then
ps -ef | grep "search-tomcat" |awk {'"'"'print $2'"'"'}| xargs kill -9
echo "Search Tomcat Shut Down"
fi
...
I have confirmed that the line
ps -ef | grep "search-tomcat"
works fine in script but:
ps -ef | grep "search-tomcat" |awk {'"'"'print $2'"'"'}
doesnt yield any results in script, but gives desired output in terminal, so there has to be some problem with awk command
xargs can be tricky - Try:
kill -9 $(ps -ef | awk '/search-tomcat/ {print $2}')
If you prefer using xargs then check man page for options for your target OS (i.e. xargs -n.)
Also noting that 'kill -9' is a non-graceful process exit mechanism (i.e. possible file corruption, other strangeness) so I suggest only using as a last resort...
:)

Can i wait for a process termination that is not a child of current shell terminal?

I have a script that has to kill a certain number of times a resource managed by a high avialability middelware. It basically checks whether the resource is running and kills it afterwards, i need the timestamp of when the proc is really killed. So i have done this code:
#!/bin/bash
echo "$(date +"%T,%N") :New measures Run" > /home/hassan/logs/measures.log
for i in {1..50}
do
echo "Iteration: $i"
PID=`ps -ef | grep "/home/hassan/Desktop/pcmAppBin pacemaker_app/MainController"|grep -v "grep" | awk {'print$2'}`
if [ -n "$PID" ]; then
echo "$(date +"%T,%N") :Killing $PID" >> /home/hassan/logs/measures.log
ps -ef | grep "/home/hassan/Desktop/pcmAppBin pacemaker_app/MainController"|grep -v "grep" | awk {'print "kill -9 " $2'} | sh
wait $PID
else
PID=`ps -ef | grep "/home/hassan/Desktop/pcmAppBin pacemaker_app/MainController"|grep -v "grep" | awk {'print$2'}`
until [ -n "$PID" ]; do
sleep 2
PID=`ps -ef | grep "/home/hassan/Desktop/pcmAppBin pacemaker_app/MainController"|grep -v "grep" | awk {'print$2'}`
done
fi
done
But with my wait command i get the following error message: wait: pid xxxx is not a child of this shell
I assume that You started the child processes from bash and then start this script to wait for. The problem is that the child processes are not the children of the bash running the script, but the children of its parent!
If You want to launch a script inside the the current bash You should start with ..
An example. You start a vim and then You make is stop pressing ^Z (later you can use fg to get back to vim). Then You can get the list of jobs by using the˙jobs command.
$ jobs
[1]+ Stopped vim myfile
Then You can create a script called test.sh containing just one command, called jobs. Add execute right (e.g. chmod 700 test.sh), then start it:
$ cat test.sh
jobs
~/dev/fi [3:1]$ ./test.sh
~/dev/fi [3:1]$ . ./test.sh
[1]+ Stopped vim myfile
As the first version creates a new bash session no jobs are listed. But using . the script runs in the present bash script having exactly one chold process (namely vim). So launch the script above using the . so no child bash will be created.
Be aware that defining any variables or changing directory (and a lot more) will affect to your environment! E.g. PID will be visible by the calling bash!
Comments:
Do not use ...|grep ...|grep -v ... |awk --- pipe snakes! Use ...|awk... instead!
In most Linux-es you can use something like this ps -o pid= -C pcmAppBin to get just the pid, so the complete pipe can be avoided.
To call an external program from awk you could try system("mycmd"); built-in
I hope this helps a bit!

linux script to kill java process

I want linux script to kill java program running on console.
Following is the process running as jar.
[rapp#s1-dlap0 ~]$ ps -ef |grep java
rapp 9473 1 0 15:03 pts/1 00:00:15 java -jar wskInterface-0.0.1-SNAPSHOT-jar-with-dependencies.jar
rapp 10177 8995 0 16:00 pts/1 00:00:00 grep java
[rapp#s1-dlap0 ~]$
You can simply use pkill -f like this:
pkill -f 'java -jar'
EDIT: To kill a particular java process running your specific jar use this regex based pkill command:
pkill -f 'java.*lnwskInterface'
If you just want to kill any/all java processes, then all you need is;
killall java
If, however, you want to kill the wskInterface process in particular, then you're most of the way there, you just need to strip out the process id;
PID=`ps -ef | grep wskInterface | awk '{ print $2 }'`
kill -9 $PID
Should do it, there is probably an easier way though...
if there are multiple java processes and you wish to kill them with one command
try the below command
kill -9 $(ps -ef | pgrep -f "java")
replace "java" with any process string identifier , to kill anything else.
pkill -f for whatever reason does not work for me. Whatever that does, it seems very finicky about actually grepping through what ps aux shows me clearly is there.
After an afternoon of swearing I went for putting the following in my start script:
(ps aux | grep -v -e 'grep ' | grep MainApp | tr -s " " | cut -d " " -f 2 | xargs kill -9 ) || true
Use jps to list running java processes. The command returns the process id along with the main class. You can use kill command to kill the process with the returned id or use following one liner script.
kill $(jps | grep <MainClass> | awk '{print $1}')
MainClass is a class in your running java program which contains the main method.

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