kill one instance of ffserver out of multiple using specific configuration file - linux

I have two instances of ffserver running both using different configuration file kept at different path.
I want to kill one of them using a script.
when i write following command :
ps -ef |grep ffs
it gives output :
root 6421 6394 0 18:47 pts/11 00:00:00 /root/bin/ffserver -f /root/newff/ffserver.conf
root 6575 6562 0 18:49 pts/11 00:00:02 /root/bin/ffserver -f /root/test/downloaded/complete/ffserver.conf
root 8453 3720 0 19:09 pts/11 00:00:00 grep ffs
Now i want to kill only one .
Is there any way to kill using command name like i can give command name with kill
pkill_like_command /root/bin/ffserver -f /root/newff/ffserver.conf
Please tell me how to do that
as simple pkill will not work.

There is an -f switch that works for pkill, so that matching considers the full command line. You can test without killing using pgrep instead. So the command line would be for example (tested on Debian with procps 1:3.2.8-9):
pkill -f "ffserver.*/root/newff/ffserver.conf"
without pkill:
kill $( ps -ef | grep "ffserver.*/root/newff/ffserver.conf" | awk '{ print $2 }' )

Related

grep for process id to get the correct value

I am using the grep command to get a specific process id, but sometimes i am getting two process ids and my output is not correct.
ps -ef |grep AS_Cluster.js
root 2711 2624 0 07:15 pts/0 00:00:00 grep AS_Cluster.js
root 14630 14625 0 Sep13 ? 00:32:36 node xx/x/xx/x/xx/AS_Cluster.js
I want to get the pid value of only node xx/xxx/xx/AS_Cluster.js this process id. Any help
on this
Use preferably pgrep(1) (probably as pgrep -f AS_cluster.js) or pipe the output of ps to some awk command (see gawk(1)) or script.
Try following
ps -ef | grep AS_Cluster.js | grep -v grep

Get a process ID

I read a lot of questions about this argument, but I can't solve my issue.
I need to get a specific process ID and I wrote the following test.sh script:
#!/bin/sh
PID=$(ps -ef | grep abc | grep -v grep | awk '{print $2}')
echo $PID
Running this script I get two different PIDs if the abc process is not running and three different PIDs if the abc process is running.
If I run the
ps -ef | grep abc | grep -v grep | awk '{print $2}'
command from shell I get the right result.
Modifing the test.sh script removing the last awk I noticed that the script prints the following output:
user1 22153 129551 0 15:56 pts/3 00:00:00 /bin/sh ./test.sh
user1 22155 22153 0 15:56 pts/3 00:00:00 /bin/sh ./test.sh
How is it possible and how can I ignore them?
If you know exactly what is the process called, use pidof, otherwise, you can just use pgrep, it saves your grep|grep|awk....
Note that, when you ps|grep regex or pgrep regex there could be multiple entries in your result.
Do not use these tools, use the right tool meant for this, command pidof with the POSIX compatible -s flag which according to the man page says,
-s Single shot - this instructs the program to only return one
pid.
Using the above,
processID=$(pidof -s "abc")
I am not a big fan of parsing the process table. It could be inaccurate. For the same reason as "why not parse ls" You may want to look at the command pgrep
My suggestion is doing
pgrep -u user1 abc

How to check the path which has been a running process?

At the begining apologize for my English.
I have a running process on server, and when I execute:
ps -aux | grep script.sh
I get such a result:
root 28104 0.0 0.0 106096 1220 pts/7 S+ 08:27 0:00 /bin/bash ./script.sh
But this script is running from eg. /home/user/my/program/script.sh
So, how I can get the full path of from where the script was running? I have many scripts which name is exactly same, but they are running from different locations and I need to know from where the given script was running.
Thanks for reply!
Try the following script:
for each in `pidof script.sh`
do
readlink /proc/$each/cwd
done
This will find the pid.s of all script.sh scripts running and find the corresponding cwd (current working directories) for /proc.
use pwdx
usage: pwdx pid ...
(show process working directory)
for example,
pwdx 20102
where 20102 is the pid
this will show the process working directory of the process
#!/bin/bash
#declare the associative array with PID as key and process directory as value
declare -A dirr
#This will get the pid of the script
pid_proc=($(ps -eaf | grep "$1.sh" | grep -v "grep" | awk '{print $2}'))
for PID in ${pid_proc[#]}
do
#using Debasish method
dirr[$PID]=$(pwdx $PID)
# Below are different process to get the CWD of running process
# using user1984289 method
#dirr[$PID]=$(readlink /proc/"$PID"/cwd)
#dirr[$PID]=$(cd /proc/$PID/cwd; /bin/pwd)
done
# iterate using the keys of the associative and get the working directory
for PID in "${!dirr[#]}"
do
echo "The script '$1.sh' with PID:'$PID' is in the directory '${dirr[$PID]}'"
done
Use pgrep to get the PIDs of your instances, and then read the link of the associated CWD directory. Basically, the same approach as #user1984289 but using pgrep instead of pidof which does not match bash script names on my system (even with the -x option):
for pid in $(pgrep -f foo.sh); do readlink /proc/$pid/cwd; done
Just change foo.sh to the name of your script.

When launching script in background I get two processes running

I came across a weird scenario that is stumping me.
I have a script that I launch in the background with an &
example:
root## some_script.sh &
After running it, I do a ps -ef | grep some_script and I see TWO processes running where the 2nd process keeps getting an different PID but it's Parent is the process that I started (like the parent process is spawning children that die off - but this was never written in the code).
example:
root## ps -ef | grep some_script.sh
root 4696 17882 0 13:30 pts/2 00:00:00 /bin/bash ./some_script.sh
root 4778 4696 0 13:30 pts/2 00:00:00 /bin/bash ./some_script.sh
root## ps -ef | grep some_script.sh
root 4696 17882 0 13:30 pts/2 00:00:00 /bin/bash ./some_script.sh
root 4989 4696 0 13:30 pts/2 00:00:00 /bin/bash ./some_script.sh
What gives here? It seems to be messing up the output and functionality of the script too and basically makes it a never ending process (when I have a defined start and stop in the script).
the script:
`
#! /bin/bash
# Set Global Variables
LOGDIR="/srv/script_logs"
OUTDIR="/srv/audits"
BUCKET_LS=$OUTDIR"/LSOUT_"$i"_"$(date +%d%b%Y)".TXT"
MYCMD1="aws s3api list-objects --bucket viddler-flvs"
MYCMD2="--starting-token"
MAX_ITEMS="--max-items 10000"
MYSTARTING_TOKEN='""'
rm tokenlog.txt flv_out.txt
while [[ $MYSTARTING_TOKEN != "null" ]]
do
# First - Get the token for the next batch
CMD_PRE="$MYCMD1 $MAX_ITEMS $MYCMD2 $MYSTARTING_TOKEN"
MYSTARTING_TOKEN=($($CMD_PRE | jq -r .NextToken))
echo $MYSTARTING_TOKEN >> tokenlog.txt
# Now - get the values of the files for the existing batch
# First - re-run the batch and get the file values we want
MYOUT2=$($CMD_PRE | (jq ".Contents[] | {Key, Size, LastModified,StorageClass }"))
echo $MYOUT2 | sed 's/[{},"]//g;s/ /\n/g;s/StorageClass://g;s/LastModified://g;s/Size://g;s/Key://g;s/^ *//g;s/ *$//g' >> flv_out.txt
#echo $STARTING_TOKEN
done
`
I guess you have
(
some shell instructions
)
inside of your .sh
This syntax executes commands in the new process (but command line would be the same).

Inconsistency between perl grep and cli grep

I am doing the following:
#!/usr/bin/perl
use strict;
use warnings;
my $proc = `ps -ef|grep -c myscriptname`;
print $proc;
This prints 2 when I run it inside the script.
ps -ef|grep -c myscriptname on the command line just shows: 1
Why?
same for my $proc = qx/ps -ef|grep -c myscriptname/
UPDATE
To be clear I run this snippet from somerandomscript.pl
Update 2
Following the advice of edorqui I remove -c getting:
12013 15777 15776 0 14:11 pts/6 00:00:00 sh -c ps -ef | grep myscriptname
12013 15779 15777 0 14:11 pts/6 00:00:00 grep myscriptname Argument "12013 15777 15776 0 14:11 pts/6 00:00:00 sh -c ps..." isn't numeric in numeric gt (>) at somerandomscript.pl line 8
from inside the script
The ps -ef command is showing the grep itself.
To skip this behaviour, try grepping for a regex condition that does not match the grep itself:
ps -ef | grep myscript[n]ame
or whatever similar can make it:
ps -ef | grep myscriptnam[e]
Explanation
If you run a sleep command in the background:
$ sleep 100 &
[1] 9768
and then look for it with ps -ef:
$ ps -ef | grep sleep
me 9768 3673 0 14:00 pts/6 00:00:00 sleep 100
me 9771 3673 0 14:00 pts/6 00:00:00 grep --color=auto sleep
You get two lines: the process itself and the grep command looking for it. To avoid it and show just the process itselves, we can either:
$ ps -ef | grep -v grep | grep sleep
or use a regex in the code so that the grep process is not matched:
$ ps -ef | grep slee[p]
me 9768 3673 0 14:00 pts/6 00:00:00 sleep 100
because line
me 9771 3673 0 14:00 pts/6 00:00:00 grep --color=auto sleep
does not match in grep slee[p].
See explanation in a related topic.
I suposse your perl script is named "myscriptname".
When you run this script, you have a new process (perl myscriptname.pl), and it's showed by the ps -ef command. The other one is related to the grep command (it has the text you are looking for)
#fedorqui's answer is right on -- the grep is matching its own invocation in the process table, and perhaps that of its parent shell, too, though timing issues mean this does not always happen from the CLI.
However, another approach, avoiding grep in favor of perl, would be:
my $count = () = qx(ps -e -o cmd) =~ /myscriptname/mg;
# Now $count tells you the number of times myscriptname appears in the process table
See this answer for why the empty parens are used above. Note, too, that you don't need the full ps output (-f), you just want to match on the command name (-o cmd).
Take a look at the pgrep and the pkill commands. These are standard Linux commands are are way easier to use than trying to do a ps and then a grep.
Also, if you do use ps, take a look at the -o options. These let you display the columns you want, and give you a way to strip out the heading.

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