I am having an issue trying to get the PID from a command using Time.
The command I use is:
{ time cp ubuntu/ubuntu-16.04.2-desktop-amd64.iso
ubuntucopia/$i-ubuntu-16.04.2-desktop-amd64.iso; }
2>> "logs/time.log" &
If I use now $!, I've get te PID from TIME. How could I do to get the pid of the command cp? Currently to solve this I am using this:
father=$!
cpPid=$(pgrep -P $father)
With this, not always I get the pid, sometimes $cpPid is empty.
Thank you!
This will get you the pid of the cp command, though you should use a search string more specific than cp, as this sample has a high potential for multiple matches.
ps -eo pid,cmd | grep cp | grep -v grep | awk '{print $1}'
Related
I am curious if anyone have similar issue when running scripts from cron. This line of script should copy opentsdb_daemon.log file to opentsdb_daemon_with_pid.log. Currently openTSDB is running on only one PID.
!/bin/sh
cp -f /opt/opentsdb/opentsdb-2.2.0/var/log/opentsdb/opentsdb_daemon.log "/opt/opentsdb/opentsdb-2.2.0/var/log/opentsdb/opentsdb_daemon_pid_$(ps -ef | grep [o]pentsdb | awk '{print $2}').log
It runs ok. File opentsdb_daemon_pid_76079.log is created but when running fron cron it's creating something like this: opentsdb_daemon_pid_63453?63454?76079.log
I have tried to run it from diffrent cron users - with same effect. I would be extremely grateful for any advice.
The command ps -ef | grep [o]pentsdb | awk '{print $2}' should return multiple PID at the time cron run it, what you get is all the PID separated by "?"
The "?" is because \n is not correctly diplayed in the filename
I assume that it is because when cron executes the command, the command appears in the process list, so :
grep [o]pentsdb is also grep by grep [o]pentsdb ;)
You can determine it by the two consecutive PID 63453 and 63454 which are the process lines "cron execute the command xxx" and the child of this process which is the "command xxx"
Maybe a solution could be to add something like :
$(ps -ef | grep [o]pentsdb |grep -Ev "grep|cron" | awk '{print $2}')
I was running an ubuntu console, when I type the following command, all the processes would be perfectly killed.
kill -9 $(ps -ef | grep 'job1/' | grep -v grep| awk '{print $2}')
But when I was trying to use crontab to call a script routinely, things went wrong.
#!/bin/bash
pid=$(ps -ef | grep 'job1/' | grep -v grep | awk '{print $2}')
echo $pid
kill -9 $pid
# the following commands were never executed
sleep 5
/data/job1/tomcat8/bin/startup.sh
The result was just like this:
15432 15438
Killed
It seems to just killed the job, but won't execute the following commands. Any idea?
If you are going to make a script that kills things by PID then you need to be very careful that you kill the right things.
You already have grep -v grep to avoid killing the grep itself, but it seems that you have not put in anything to protect against the script killing itself. Since you know your own PID you could grep -v that, but what if you are 123 and one of the things you want to kill is 1234? Probably safer to go by script name.
I made an alias for this function in order to kill processes in bash:
On my .bashrc file
kill_process(){
# $1 being a parameter for the process name
kill $(ps ax | grep "$1" | awk '{print $1}')
}
alias kill_process=kill_process
So, suppose I want to kill the meteor process:
Let's see all meteor processes:
ps aux | grep 'meteor' | awk '{print $2}'
21565
21602
21575
21546
Calling the kill_process function with the alias
kill_process meteor
bash: kill: (21612) - No such process
So, the kill_process function effectively terminates the meteor processes, but it's kill command looks for an inexistent pid. Notice the pid 21612 wasn't listed by ps aux | grep. Any ideas to improve the kill_process function to avoid this?
I think in your case the killall command would do what you want:
killall NAME
The standard way of killing processes by name is using killall, as Swoogan suggests in his answer.
As to your kill_process function, the grep expression that filters ps will match the very own grep process (you can see this running the pipeline without awk), but by the time kill is invoked, that process is no longer running. That's the message you see.
Each time you run the command, grep runs again with a new PID: that's the reason you can't find it on the list when you test it.
You could:
Run ps first, pipe it into a file or variable, then grep
Filter grep's PID out of the list
(Simpler) supress kill output:
kill $(...) 2>/dev/null
Okay so here's another one about the StarMade server.
Previously I had this script for detecting a crash, it would simply search through the logs:
#!/bin/bash
cd "$(dirname "$0")"
if ( grep "[SERVER] SERVER SHUTDOWN" log.txt.0); then
sleep 7; kill -9 $(ps -aef | grep -v grep | grep 'StarMade.jar' | awk '{print $2}')
fi
It would find "[SERVER] SERVER SHUTDOWN" and kill the process after that, however this is not a waterproof method, because with different errors it could be possible that the message doesn't appear, rendering this script useless.
So I have this tool that can send commands to the server, but returns an EOF exception when the server is in a crashed state. I basically want to grab the output of this command, and use it in the if-statement above, instead of the current grep command, in such a way that it would execute the commands below when the grep finds "java.io.EOFException".
I could make it write the output to a file and then grep it from there, but I wonder, isn't there a better/more efficient method to do this?
EDIT: okay, so after a bit of searching I put together the following:
if ( java -jar /home/starmade/StarMade/StarNet.jar xxxxx xxxxx /chat) 2>&1 > /dev/null |grep java.io.EOFException);
Would this be a valid if-statement? I need it to match "java.io.EOFException" in the output of the first command, and if it matches, to execute something with "then" (got that part working).
Not sure to solve your problem, but this line:
ps -aef | grep -v grep | grep 'StarMade.jar' | awk '{print $2}'
could be change to
ps -aef | awk '/[S]tarMade.jar/ {print $2}'
The [S] prevents awk from finding itself.
Or just like this to get the pid
pidof StarMade.jar
Is there any way to find the pid of children of a program ?
For example I'm starting pppoe connection using system program:
pon dsl-provider
The program will exit after establishing connection and will spawn a pppd needed for connection:
ps wx | grep pppd
882 ? S 0:01 /usr/sbin/pppd call dsl-provider
The thing is (I was doing that until now) that I don't want to grep in ps listing, I want an exact answer, and I need this in many circumstances (the above is only an example). How can I do that?
Try pstree with the -p option to show the process tree of a process and its children with pids appended:
$ pstree -p `pgrep pppd`
You can try this
# somehow get the PID of the parent (882 in your case)
PID=`ps wx | grep pppd | awk '{ print $1; }'`
# formatted output (includes the parent)
ps ax --format pid,ppid,command | grep $PID | grep -v grep
I'd use ps --ppid ORIGINAL_PROGRAMS_PID although it might not work if the original program exited.