In one of my tools is needed the PID of specyfic process in system. I try do this by following command:
parasit#host:~/# ps -ef | grep beam.smp |grep -v grep |awk '{ print $2 }' |head -n1
11982
Works fine, but when i try use the same command in script in the vast majority of cases got PID of grep instead of target process (beam.smp in this case) despite of 'grep -v grep`.
parasit#host:~/# cat getPid.sh
#!/bin/bash
PROC=$1
#GET PID
CMD="ps -ef | grep $PROC |grep -v grep |awk '{ print \$2 }' |head -n1"
P=`eval $CMD`
parasit#host:~/# bash -x ./getPid.sh beam.smp
+ PROC=beam.smp
+ CMD='ps -ef |grep beam.smp |grep -v grep |awk '\''{ print $2 }'\'' |head -n1'
++ eval ps -ef '|grep' beam.smp '|grep' -v grep '|awk' ''\''{' print '$2' '}'\''' '|head' -n1
+++ head -n1
+++ awk '{ print $2 }'
+++ grep -v grep
+++ grep beam.smp
+++ ps -ef
+ P=2189
Interestingly, it is not deterministic, I know it sounds strange, but sometimes it works OK, and sometimes no, I have no idea what it depends on.
How it is possibile? Is there any better method to get rid of "grep" from results?
BR
Parasit
pidof -s is made for that (-s: single ID is returned):
pidof -s "beam.smp"
However, pidof also returns defunct (zombie, dead) processes. So here's a way to get PID of the first alive-and-running process of a specified command:
# function in bash
function _get_first_pid() {
ps -o pid=,comm= -C "$1" | \
sed -n '/'"$1"' *$/{s:^ *\([0-9]*\).*$:\1:;p;q}'
}
# example
_get_first_pid "beam.smp"
-o pid=,comm=: list only PID and COMMAND columns; ie. only list what we need to check; if all are listed then it is more difficult to process later on
-C "$1": of the command specified in -C; ie. only find the process of that specific command, not everything
sed: print only PID for first line that do not have "defunct" or anything after the base command name
Related
I got confused about this line of code, could anyone explain how this code work? I can understand that its using a pipeline, but codes in the middle confuses me.
for pid in $(ps -e -f | grep $1 | grep -v $0 | awk '{print $2}')"
Check below details to understand the command, full command will be like this-
cat script.sh
for pid in $(ps -e -f | grep $1 |grep -v $0 | awk '{print $2}')
do
kill -9 $pid
done
You need to execute it like below -
./script.sh vipin
step1 : ps -e -f (will print all the processes running in the server)
step2 : ps -e -f|grep $1 (considering $1 is variable for current user,
in my case is vipin(user) which i will pass with script,so step2
will filter all the process for that user.
step3 : And $0 is the script name (script.sh), which you don't want to kill
that is why you are using grep -v(to exclude)
step4 : awk '{print $2}' to fetch only the process number.
I want to kill all processes containing some string. I wrote script for doing this. However, when I execute it, it gets "Killed" signal after first iteration of for loop. This is my code:
#!/bin/bash
executeCommand () {
local pname="$1";
echo $HOSTNAME;
local search_terms=($(ps aux | grep $pname | awk '{print $2}'))
for pros in "${search_terms[#]}"; do
kill -9 "$pros"
echo $pros
done
exit
}
executeCommand "$1" # get the string that process to be killed contains
I execute it like ./my_script.sh zookeeper.
When I delete the line containing kill command, for loop executes until end, otherwise, after first kill command, I get as an output "Killed" and program exits.
What is possible reason for this, and any other solution to reach my goal?
The silly (faulty, buggy) way to do this is to add grep -v grep to your pipeline:
# ${0##*/} expands to the name of the running script
# ...thus, we avoid killing either grep, or the script itself
ps aux | grep -e "$pname" | egrep -v "grep|${0##*/}" | awk '{print $2}'
The better way is to use a tool built for the job:
# pkill already, automatically, avoids killing any of its parent processes
pkill "$pname"
That said, matching processes by name is a bad practice to start with -- you'll also kill less yourproc.log or vim yourproc.conf, not just yourproc. Don't do it; instead, use a proper process supervision system (upstart, DJB daemontools, Apple launchd, systemd, etc) to monitor your long-running daemons and kill or restart them when needed.
By the way -- there's no need for a for loop at all: kill can be passed multiple PIDs on a single invocation, like so:
# a bit longer and bash-specific, but avoids globbing
IFS=$'\n' read -r -d '' -a pids \
< <(ps auxw | awk -v proc="$pname" -v preserve="${0##*/}" \
'$0 ~ proc && $0 !~ preserve && ! /awk/ { print $2 }' \
&& printf '\0')
kill -- "${pids[#]}"
...which could also be formulated as something like:
# setting IFS and running `set -f` necessary to make unquoted expansion safe
( IFS=$'\n'; set -f; exec kill -- \
$(ps auxw | awk -v proc="$pname" -v preserve="${0##*/}" \
'$0 ~ proc && $0 !~ preserve && ! /awk/ { print $2 }') )
grep will show , it's own process . it should be removed using grep -v option
Try like this
for i in ` ps -ef | grep "$pname" | grep -v grep | awk '{print $2}'`
do
kill -9 $i
done
mySample.sh
pid=$(ps -Af | grep $1 | grep -v grep | awk ' { print $2 } ');
echo $pid
The above command is printing and killing the temporary process that was created for grep
Even though i do not have any process running with Abcd,
This is printing pid
Any ways to ignore it,
iam actually ignoring it using grep -v, still...
./mySample.sh Abcd
6251 6378 6379
Any Issue in fetching the process id.?
Basic command line output is below,After running a process with name Acc_Application_One
[root#localhost Desktop]# ps -Af | grep Acc
root 6251 2758 0 16:16 pts/1 00:00:00 ./Acc_Application_One
root 7288 2758 0 16:57 pts/1 00:00:00 grep Acc
Changed mySample.sh
pgrep -fl "$1"
And the output is
[root#localhost Desktop]# mySample.sh Acc_Application_One
6251 7289
To kill a process with the pattern anywhere in command line use pkill -f:
pkill -f "$1"
As per man pkill:
-f Match the pattern anywhere in the full argument string of the process instead of just the executable name.
Similarly you can use pgrep -f "$1" to list the process id of the matching process.
Try something much simpler:
pid=$(pgrep "$1")
And if you want to kill it:
pkill "$1"
The problem will become clear when you remove the awk: mySample.sh will have Abcd as well.
ps -Af | grep " $1" | grep -Ev "grep|$0" | awk ' { print $2 } '
Changed mySample.sh script with below code
And This is just fetching the processId using the parameter sent
and killing it
pid=$(pgrep -fl $1 | grep -v '[k]ill_script'| awk ' { print $1 } ')
echo $pid
if [[ -n ${pid} ]]; then
echo "Stopping Acc Application $1 with pid=${pid}"
kill -9 ${pid}
fi
Thanks
I am writing one shell script and I want to get PID of one process with name as "ABCD". What i did was :
process_id=`/bin/ps -fu $USER|grep "ABCD"|awk '{print $2}'`
This gets PID of two processes i.e. of process ABCD and the GREP command itself what if I don't want to get PID of GREP executed and I want PID only of ABCD process?
Please suggest.
Just grep away grep itself!
process_id=`/bin/ps -fu $USER| grep "ABCD" | grep -v "grep" | awk '{print $2}'`
Have you tried to use pidof ABCD ?
It's very straight forward. ABCD should be replaced by your process name.
#!/bin/bash
processId=$(ps -ef | grep 'ABCD' | grep -v 'grep' | awk '{ printf $2 }')
echo $processId
Sometimes you need to replace ABCD by software name. Example - if you run a java program like java -jar TestJar.jar & then you need to replace ABCD by TestJar.jar.
ps has an option for that:
process_id=`/bin/ps -C ABCD -o pid=`
You can also do away with grep and use only awk.
Use awk's expression matching to match the process name but not itself.
/bin/ps -fu $USER | awk '/ABCD/ && !/awk/ {print $2}'
You can use this command to grep the pid of a particular process & echo $b to print pid of any running process:
b=`ps -ef | grep [A]BCD | awk '{ printf $2 }'`
echo $b
ps | pgrep ABCD
You can try the above command to return the process id of the ABCD process.
I found a better way to do this.
top -n 1 | grep "##" | grep -Eo '^[^ ]+'
I have a for loop to get the list of PID's and kill each PID. I want to display the entire line of PS output and write it to the /tmp/outfile . But from each line of PS output each field(PID,PPID,...) is written along with a new line in the /tmp/outfile. So if PS output has three lines as output i want to log these three lines into /tmp/outfile but it's breaking each field in the line and adding a new line. how can i do it.
for list in `ps -ef | grep "${process_name}" | grep -v "${SCRIPTNAME}" | grep -v grep`
do
echo "$list" >> $CUSTOM_TMP/test5566
PID=`echo $list | awk '{print $2}'`
kill -TERM "$list"
done
Your for loop does not iterate the lines but each individual field.
Also your kill command was slightly wrong.
Just change your code to something like:
ps -ef | grep "${process_name}" | grep -v "${SCRIPTNAME}" | grep -v grep | while read list
do
echo "$list" >> $CUSTOM_TMP/test5566
PID=`echo $list | awk '{print $2}'`
kill -TERM "$PID"
done
Isn't it easier to use the killall command for what you are trying to do?
No need for a loop at all. And this uses tee to write your temp file.
list=$(ps -ef | grep "${process_name}" | grep -v "${SCRIPTNAME}" | grep -v grep | tee $CUSTOM_TMP/test5566 | awk '{printf "%s ", $2')
kill -TERM $list
You want to run ps before looping:
ps -ef | grep $"{process_name}" | grep -v "${SCRIPTNAME}" | grep -v grep > $CUSTOM_TMP/test5566 2>/dev/null
for PID in `cat $CUSTOM_TMP/test5566 | awk '{print $2}'`; do
kill -TERM $PID
done
rm -f $CUSTOM_TMP/test5566
I would also insert some sanity, possibly using wc to make sure the file actually got some data from ps.
Just move the awk part to the top line, otherwise your code is fine.
for list in `ps -ef | grep "${process_name}" | grep -v "${SCRIPTNAME}" | grep -v grep | awk '{print $2}`
do
echo "$list" >> $CUSTOM_TMP/test5566
PID=`echo $list`
kill -TERM "$list"
done
For a one liner - if your system has pgrep --
pgrep -d ' ' ${process_name} > kill.log && kill -TERM $(< kill.log)