I need to start a program, which uses a serial port from within a bash script. The matter is that prior to doing that I need to kill "-sh" process in order to release the serial port occupied by it (I use a serial console and this is the only way to communicate with Linux). When I kill "-sh" my program doesn't start, however the bash script continues to execute. If I don't kill "-sh" my program normally starts. See code below for details:
#!/bin/bash
SH_PID=`ps -o comm,pid | egrep -e '^sh' | awk -F " " '{print $2}'`
kill -9 $SH_PID
myprog #start my program
while true
do
sleep 10
echo "script is running..." > /dev/ttyS0
done
Any thoughts?
What if you kill your shell after running your program in background:
#!/bin/bash
SH_PID=`ps -o comm,pid | egrep -e '^sh' | awk -F " " '{print $2}'`
nohup myprog & #start my program in background
kill --HUP $SH_PID
while true
do
sleep 10
echo "script is running..." > /dev/ttyS0
done
Related
give some advice, please.
I am trying to kill processes remotely (ssh to hostname), find some processes and kill them. But I have a condition: Do not kill java process, sshd and gnome.
Here is example (I just do echo except kill):
#/bin/sh -x.
HOSTFILE=$1
vars=`cat $HOSTFILE`
for i in $vars; do
ssh "$i" /bin/bash <<'EOF'
echo $(hostname)
ps aux | grep -e '^sys_ctl'| grep -v "java" | grep -v "sshd" | \
grep -v "gnome" | awk '{print $2$11}'| for i in `xargs echo`; do echo $i; done;
EOF
done
The result is:
host1:
21707/bin/bash
21717ps
21718grep
21722awk
21723/bin/bash
21724xargs
host2:
15241/bin/bash
15251ps
15252grep
15256awk
15257/bin/bash
15258xargs
89740-bash
98467sleep
98469sleep
98471sleep
98472sleep
98474sleep
98475sleep
I want to kill (output), only sleep processes, not grep,awk,bash,xargs,ps
Can you suggest something elegant?
why not just : kill $(pgrep -f sleep)
or : pkill -f sleep
I start the following script which I run in a bash shell(let's say shell1) in foreground and from another shell(shell2) I send the kill -SIGUSR1 pidof(scriptA). Nothing happens. What am I doing wrong ? I tried other signals(SIGQUIT etc) but the result is same.
test_trap.sh
function iAmDone { echo "Trapped Signal"; exit 0 }
trap iAmDone SIGUSR1
echo "Running... "
tail -f /dev/null # Do nothing
In shell1
./test_trap.sh
In shell2
kill -SIGUSR1 ps aux | grep [t]est_trap | awk '{print $2}'
The trap is not executed until tail finishes. But tail never finishes. Try:
tail -f /dev/null &
wait
The trap will execute without waiting for tail to complete, but if you exit the tail will be left running. So you'll probably want a kill $! in the trap.
I have a script that has to kill a certain number of times a resource managed by a high avialability middelware. It basically checks whether the resource is running and kills it afterwards, i need the timestamp of when the proc is really killed. So i have done this code:
#!/bin/bash
echo "$(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!
I have a job dispatcher bash shell script containing below codes:
for (( i=0; i<$toBeDoneNum; i=i+1 ))
do
while true
do
processNum=`ps aux | grep Checking | wc -l`
if [ $processNum -lt $maxProcessNum ]; then
break
fi
echo "Too many processes: Max process is $maxProcessNum."
sleep $sleepSec
done
java -classpath ".:./conf:./lib/*" odx.comm.cwv.main.Checking $i
done
I run the script like this to be in the background:
./dispatcher.sh &
I want to terminate this dispatcher process with kill -9. But I didn't record the pid of the dispatcher process at the first time. Instead I used jobs to show all the process but it shows nothing. Even this fg cannot bring the process to foreground.
fg
bash: fg: current: no such job
But I think this dispatcher process is still running because it still continues to assign java program to run. How should I terminate this job dispatcher bash shell script process?
Edit: I used jobs, jobs -l, jobs -r and jobs -s. Nothing showed.
create test.sh with content
sleep 60
then
jobs -l | grep 'test.sh &' | grep -v grep | awk '{print $2}'
this gives me the process id on Ubuntu and OSX
you can assign it to a variable and then kill it
pid=`jobs -l | grep 'test.sh &' | grep -v grep | awk '{print $2}'`
kill -9 $pid
Script which executes commands in infinite loop in background
<SOMETHING ELSE AT START OF SCRIPT>
cmd='while true;
do
ps aux | head;
sleep 1;
done > $FILE'
ssh root#$SERVER $cmd &
...
...
<SOME OTHER TASKS>
...
...
( at the end of this script, how to kill the above snippet executing in remote server)
[ kindly note i dont want to wait as the while loop is infinite ]
Read and tried some posts from stackoverflow, but could not find exact solution for this problem.
Rather than an infinite loop, use a sentinel file:
cmd='while [ -r /tmp/somefile];
do
# stuff
done > $FILE'
ssh root#$SERVER touch /tmp/somefile
ssh root#$SERVER $cmd &
# do other stuff
ssh root#$SERVER rm -f /tmp/somefile
This follows your current practice of putting the remote command in a variable, but the arguments against that cited elsewhere should be considered.
If you want to kill the ssh process running in background at the end of your script, just do:
kill $!
I assume this is the only (or the last) process you started in background.
Try following sequence
CTRL+Z
fg
CTRL+C
or
jobs
kill %jobspec
To kill everything belonging to user logged in you could try:
whois=`w|grep $user|awk '{print $2}'`;user=root; ssh $user#server -C "ps auwx|grep $whois|awk '{print \$2}'"
This will list all the processes owned by the user you just logged in as - just add |xargs kill -9
whois=`w|grep $user|awk '{print $2}'`;user=root; ssh $user#server -C "ps auwx|grep $whois|awk '{print \$2}'|xargs kill -9 "
whois=`w|grep $user|awk '{print $2}'`;user=root; ssh $user#server -C "ps auwx|grep $whois|awk '{print \$2}'|awk '{print "kill -9 " $1}'|/bin/sh "