I don't want to run an external program (subl - sublime text) at a certain point of time, I want to run it for a certain amount of time. I basically need to boot up the program for 10 seconds then kill it - multiple times - because of its install and update process.
How can I do this?
You may have a timeout command on your system, which uses a standard alarm signal to terminate a process. I've never quite understood why no shell provides access to this feature as a builtin. If you don't have timeout on your system, you can simulate it with
my_program & pid=$!
sleep 10
kill "$pid"
Use timeout:
timeout 5s <program>
You can also specify the signal which need to be passed to terminating the process.
timeout -s9 5s <program>
(OR)
timeout --signal=KILL 5s <program>
Test:
$ time timeout 5s sleep 40
real 0m5.002s
user 0m0.001s
sys 0m0.001s
I ended up using this in my script
/usr/bin/subl
SPID="$(ps -A | grep sublime_text | awk '{print $1}')"
sleep 5
kill "$SPID"
unset "$SPID"
Related
I have a bash script where I would like to get know how much percentage of CPU time a process uses until I kill it in the last line of the script.
I know that I could normally do this via the time -v command, however my process is Erlang/OTP based and by using the time command it only measures the startup process statistics.
Therefore I'd like to use the process PID I can get easily and use that one to get the CPU time percentage until the end of the script.
Currently I'm using pidstat but it is only giving me statistics for linear time intervals.
I want to measure the exact timeinterval from when the process started until it gets killed.
Peak RAM statistics woul also be nice.
Could you recommend me any command I could use in this case?
This is my bash script:
sudo emqx start
sleep 10
mypid=$(sudo emqx pid)
echo $mypid
sudo pidstat -h -r -u -v -p "$mypid" 5 > $local/server_results/test1/emqxstats_$b.txt &
# process for load testing
# jthreads = amount of publishing users
sleep 5
until sudo ~/Downloads/apache-jmeter-5.2.1/bin/jmeter -n -t $local/testplans/csv.jmx -Jport=$a | grep -m 1 "... end of run"; do : ; done
sudo emqx stop
kill %!
So I want to measure the CPU percentage from the interval between starting mosquitto and until the Apache Jmeter test finished when it reaches the last 2 lines.
Kind regards
I found the command I was looking after some more research.
ps -o pcpu -p $pid
this was exactly the command I needed, because it calculates the percentage over the lifetime of the process.
For killing a process after a given timeout in Bash, there is a nice command called timeout. However, I'm running my program on a multi-user server, and I don't want the performance of my program to be influenced by others. Is there a way to kill a process in Bash, after a given time that the program is really running?
On Bash+Linux, you can use ulimit -t. Here's from help ulimit:
-t the maximum amount of cpu time in seconds
Here's an example:
$ time bash -c 'ulimit -t 5; while true; do true; done'
Killed
real 0m8.549s
user 0m4.983s
sys 0m0.008s
The infinite loop process was scheduled (i.e. actually ran) for a total of 5 seconds before it was killed. Due to other processes competing for the CPU at the same time, this took 8.5 seconds of wall time.
A command like sleep 3600 would never be killed, since it doesn't use any CPU time.
I am using Peppermint distro. I'm new to linux, however I need to display system processes, then create a new process to run in the background for 2 minutes, I need to prove its running and then terminate it before the 2 minutes is up.
So far i'm using xlogo to test my process is working. I have
ps
xlogo &
TASK_PID=$!
if pgrep -x xlogo>/dev/null 2>&1
then
ps
sleep 15
kill $TASK_PID
ps
fi
I can't seem to figure out a way to give it an initial time of 2 minutes but then kill it after 15 seconds anyway.
any help appreciated!
If you want the command to originally have a time limit of 2 minutes you could do
timeout 2m xlogo &
of course, then your $! will be of the timeout command. If you're using pgrep and satisfied it's only finding the process you care about though, you could use pkill instead of the PID to kill the xlogo
Of course, killing the timeout PID will also kill xlogo, so you might be able to keep things as-is for the rest if you're happy with how that works.
I am trying to find a way to monitor a process. If the process is not running it should be checked again to make sure it has really crashed. If it has really crashed run a script (start.sh)
I have tried monit with no succes, I have also tried adding this script in crontab: I made it executable with chmod +x monitor.sh
the actual program is called program1
case "$(pidof program | wc -w)" in
0) echo "Restarting program1: $(date)" >> /var/log/program1_log.txt
/home/user/files/start.sh &
;;
1) # all ok
;;
*) echo "Removed double program1: $(date)" >> /var/log/program1_log.txt
kill $(pidof program1 | awk '{print $1}')
;;
esac
The problem is this script does not work, I added it to crontab and set it to run every 2 minutes. If I close the program it won't restart.
Is there any other way to check a process, and run start.sh when it has crashed?
Not to be rude, but have you considered a more obvious solution?
When a shell (e.g. bash or tcsh) starts a subprocess, by default it waits for that subprocess to complete.
So why not have a shell that runs your process in a while(1) loop? Whenever the process terminates, for any reason, legitimate or not, it will automatically restart your process.
I ran into this same problem with mythtv. The backend keeps crashing on me. It's a Heisenbug. Happens like once a month (on average). Very hard to track down. So I just wrote a little script that I run in an xterm.
The, ahh, oninter business means that control-c will terminate the subprocess and not my (parent-process) script. Similarly, the sleep is in there so I can control-c several times to kill the subprocess and then kill the parent-process script while it's sleeping...
Coredumpsize is limited just because I don't want to fill up my disk with corefiles that I cannot use.
#!/bin/tcsh -f
limit coredumpsize 0
while( 1 )
echo "`date`: Running mythtv-backend"
# Now we cannot control-c this (tcsh) process...
onintr -
# This will let /bin/ls directory-sort my logfiles based on day & time.
# It also keeps the logfile names pretty unique.
mythbackend |& tee /....../mythbackend.log.`date "+%Y.%m.%d.%H.%M.%S"`
# Now we can control-c this (tcsh) process.
onintr
echo "`date`: mythtv-backend exited. Sleeping for 30 seconds, then restarting..."
sleep 30
end
p.s. That sleep will also save you in the event your subprocess dies immediately. Otherwise the constant respawning without delay will drive your IO and CPU through the roof, making it difficult to correct the problem.
Is there any bash/linux command to launch a long-running command, then kill it after n minutes? I guess I could hack something up with perl using fork and kill, but does anyone know of something already out there?
See the timeout command now in most GNU/Linux distros.
timeout -sHUP 10m command
The same functionality can be achieved with http://www.pixelbeat.org/scripts/timeout
Try it with this one, it starts your command in the background, stores it's PID in $P, waits for some time and kills it with a SIGHUP.
yourCommand & PID=$!
sleep ${someMinutes}m
kill -HUP $PID
Cheers
PS: that assumes a sleep that knows about Nm (minutes), else, you might want to do some math :)
n=5
some_command &
pid=$!
at now + $n minutes <<<"kill -HUP $pid"
The benefit of using at over waiting for sleep is that your script wont block waiting for the sleep to expire. You can go and do other things and at will asynchronously fire at the specified time. Depending on your script that may be a very important feature to have.