Related
i have some Watcher.sh script running on a directory /foo/bar. When something happens in /foo/bar it starts another script (Updater.sh) which first sleeps for 30 seconds and then do stuff. The Watcher.sh script is managed by supervisor, which is configured to restart the script if it ends. So when there was a change in /foo/bar and the Updater.sh is started (in a subprocess), the Watcher script should end and get started again by supervisor. If there is a second change in /foo/bar the new Updater.sh script should end the first one and start again its 30 second sleep before doing stuff.
Watcher.sh script:
#!/usr/bin/env bash
echo "Started inotifywait with $BASHPID ID"
inotifywait -q -e modify,move,create,delete /foo/bar
/updater.sh &
Updater.sh script:
#!/usr/bin/env bash
echo "Start Update process $BASHPID"
FILE=/var/run/updater.pid
if test -f "$FILE" ; then
kill -9 `cat /var/run/updater.pid`
rm /var/run/updater.pid
fi
echo $BASHPID > /var/run/updater.pid
echo "Change in /foo/bar, reload soon"
sleep 30
supervisorctl reload
My problem is that it just don't happen. The Watcher.sh script is restarted, but the Updater.sh script is not killed at all. I checked the /var/run/updater.pid which is definitely set after the first change, but it just don't enter the if case and even when it does, it does not continue after the kill.
Would be great if somebody knows where i do something wrong, it should be simple right?..
EDIT 1:
Use the following code in the updater.sh to not listen on a pid file
if ps -ef | grep -vE "grep|$BASHPID" | grep updater | awk '{print $2}' ; then
echo "Kill it"
kill -9 `ps -ef | grep -vE "grep|$BASHPID" | grep updater | awk '{print $2}'`
fi
I have made an Auto Clicker and was wondering how i would kill it using
kill [pid]
My auto Clicker works like this:
while true [1]; do
xdotool click --repeat 10000 --delay 150 1
done
code I have used to try and terminate running proccess:
ps -ef | grep AutoClicker | grep -v grep | xargs kill -9
I found this code on another post, however i have had no luck with it.
pkill -f AutoClicker or kill $(pgrep -f AutoClicker)
If you run your code:
ps -ef | grep AutoClicker | grep -v grep | xargs kill -9
you should get an error message from kill.
kill expects a list of process ids not usernames, times, and random strings.
You need to filter out everything except the pids with something like:
ps -ef | grep AutoClicker | grep -v grep | awk '{print $2}' | xargs kill
Instead of searching for the process ID, use your own "PID file". I'll demonstrate with sleep in place of xdotool.
echo $$ > /tmp/my.pid
while true [1]; do
echo "clicking"
sleep 5
done
# rm -f /tmp/my.pid
I can run this script in another terminal window or the background. The important thing is that /tmp/my.pid contains the process ID of this running script. You can stop it with:
kill $(</tmp/my.pid)
This interrupts the while-loop. Need to figure out how to remove the PID file...
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.
Is there any builtin feature in Bash to wait for a process to finish?
The wait command only allows one to wait for child processes to finish.
I would like to know if there is any way to wait for any process to finish before proceeding in any script.
A mechanical way to do this is as follows but I would like to know if there is any builtin feature in Bash.
while ps -p `cat $PID_FILE` > /dev/null; do sleep 1; done
To wait for any process to finish
Linux (doesn't work on Alpine, where ash doesn't support tail --pid):
tail --pid=$pid -f /dev/null
Darwin (requires that $pid has open files):
lsof -p $pid +r 1 &>/dev/null
With timeout (seconds)
Linux:
timeout $timeout tail --pid=$pid -f /dev/null
Darwin (requires that $pid has open files):
lsof -p $pid +r 1m%s -t | grep -qm1 $(date -v+${timeout}S +%s 2>/dev/null || echo INF)
There's no builtin. Use kill -0 in a loop for a workable solution:
anywait(){
for pid in "$#"; do
while kill -0 "$pid"; do
sleep 0.5
done
done
}
Or as a simpler oneliner for easy one time usage:
while kill -0 PIDS 2> /dev/null; do sleep 1; done;
As noted by several commentators, if you want to wait for processes that you do not have the privilege to send signals to, you have find some other way to detect if the process is running to replace the kill -0 $pid call. On Linux, test -d "/proc/$pid" works, on other systems you might have to use pgrep (if available) or something like ps | grep "^$pid ".
I found "kill -0" does not work if the process is owned by root (or other), so I used pgrep and came up with:
while pgrep -u root process_name > /dev/null; do sleep 1; done
This would have the disadvantage of probably matching zombie processes.
This bash script loop ends if the process does not exist, or it's a zombie.
PID=<pid to watch>
while s=`ps -p $PID -o s=` && [[ "$s" && "$s" != 'Z' ]]; do
sleep 1
done
EDIT: The above script was given below by Rockallite. Thanks!
My orignal answer below works for Linux, relying on procfs i.e. /proc/. I don't know its portability:
while [[ ( -d /proc/$PID ) && ( -z `grep zombie /proc/$PID/status` ) ]]; do
sleep 1
done
It's not limited to shell, but OS's themselves do not have system calls to watch non-child process termination.
FreeBSD and Solaris have this handy pwait(1) utility, which does exactly, what you want.
I believe, other modern OSes also have the necessary system calls too (MacOS, for example, implements BSD's kqueue), but not all make it available from command-line.
From the bash manpage
wait [n ...]
Wait for each specified process and return its termination status
Each n may be a process ID or a job specification; if a
job spec is given, all processes in that job's pipeline are
waited for. If n is not given, all currently active child processes
are waited for, and the return status is zero. If n
specifies a non-existent process or job, the return status is
127. Otherwise, the return status is the exit status of the
last process or job waited for.
Okay, so it seems the answer is -- no, there is no built in tool.
After setting /proc/sys/kernel/yama/ptrace_scope to 0, it is possible to use the strace program. Further switches can be used to make it silent, so that it really waits passively:
strace -qqe '' -p <PID>
All these solutions are tested in Ubuntu 14.04:
Solution 1 (by using ps command):
Just to add up to Pierz answer, I would suggest:
while ps axg | grep -vw grep | grep -w process_name > /dev/null; do sleep 1; done
In this case, grep -vw grep ensures that grep matches only process_name and not grep itself. It has the advantage of supporting the cases where the process_name is not at the end of a line at ps axg.
Solution 2 (by using top command and process name):
while [[ $(awk '$12=="process_name" {print $0}' <(top -n 1 -b)) ]]; do sleep 1; done
Replace process_name with the process name that appears in top -n 1 -b. Please keep the quotation marks.
To see the list of processes that you wait for them to be finished, you can run:
while : ; do p=$(awk '$12=="process_name" {print $0}' <(top -n 1 -b)); [[ $b ]] || break; echo $p; sleep 1; done
Solution 3 (by using top command and process ID):
while [[ $(awk '$1=="process_id" {print $0}' <(top -n 1 -b)) ]]; do sleep 1; done
Replace process_id with the process ID of your program.
Blocking solution
Use the wait in a loop, for waiting for terminate all processes:
function anywait()
{
for pid in "$#"
do
wait $pid
echo "Process $pid terminated"
done
echo 'All processes terminated'
}
This function will exits immediately, when all processes was terminated. This is the most efficient solution.
Non-blocking solution
Use the kill -0 in a loop, for waiting for terminate all processes + do anything between checks:
function anywait_w_status()
{
for pid in "$#"
do
while kill -0 "$pid"
do
echo "Process $pid still running..."
sleep 1
done
done
echo 'All processes terminated'
}
The reaction time decreased to sleep time, because have to prevent high CPU usage.
A realistic usage:
Waiting for terminate all processes + inform user about all running PIDs.
function anywait_w_status2()
{
while true
do
alive_pids=()
for pid in "$#"
do
kill -0 "$pid" 2>/dev/null \
&& alive_pids+="$pid "
done
if [ ${#alive_pids[#]} -eq 0 ]
then
break
fi
echo "Process(es) still running... ${alive_pids[#]}"
sleep 1
done
echo 'All processes terminated'
}
Notes
These functions getting PIDs via arguments by $# as BASH array.
Had the same issue, I solved the issue killing the process and then waiting for each process to finish using the PROC filesystem:
while [ -e /proc/${pid} ]; do sleep 0.1; done
There is no builtin feature to wait for any process to finish.
You could send kill -0 to any PID found, so you don't get puzzled by zombies and stuff that will still be visible in ps (while still retrieving the PID list using ps).
If you need to both kill a process and wait for it finish, this can be achieved with killall(1) (based on process names), and start-stop-daemon(8) (based on a pidfile).
To kill all processes matching someproc and wait for them to die:
killall someproc --wait # wait forever until matching processes die
timeout 10s killall someproc --wait # timeout after 10 seconds
(Unfortunately, there's no direct equivalent of --wait with kill for a specific pid).
To kill a process based on a pidfile /var/run/someproc.pid using signal SIGINT, while waiting for it to finish, with SIGKILL being sent after 20 seconds of timeout, use:
start-stop-daemon --stop --signal INT --retry 20 --pidfile /var/run/someproc.pid
Use inotifywait to monitor some file that gets closed, when your process terminates. Example (on Linux):
yourproc >logfile.log & disown
inotifywait -q -e close logfile.log
-e specifies the event to wait for, -q means minimal output only on termination. In this case it will be:
logfile.log CLOSE_WRITE,CLOSE
A single wait command can be used to wait for multiple processes:
yourproc1 >logfile1.log & disown
yourproc2 >logfile2.log & disown
yourproc3 >logfile3.log & disown
inotifywait -q -e close logfile1.log logfile2.log logfile3.log
The output string of inotifywait will tell you, which process terminated. This only works with 'real' files, not with something in /proc/
Rauno Palosaari's solution for Timeout in Seconds Darwin, is an excellent workaround for a UNIX-like OS that does not have GNU tail (it is not specific to Darwin). But, depending on the age of the UNIX-like operating system, the command-line offered is more complex than necessary, and can fail:
lsof -p $pid +r 1m%s -t | grep -qm1 $(date -v+${timeout}S +%s 2>/dev/null || echo INF)
On at least one old UNIX, the lsof argument +r 1m%s fails (even for a superuser):
lsof: can't read kernel name list.
The m%s is an output format specification. A simpler post-processor does not require it. For example, the following command waits on PID 5959 for up to five seconds:
lsof -p 5959 +r 1 | awk '/^=/ { if (T++ >= 5) { exit 1 } }'
In this example, if PID 5959 exits of its own accord before the five seconds elapses, ${?} is 0. If not ${?} returns 1 after five seconds.
It may be worth expressly noting that in +r 1, the 1 is the poll interval (in seconds), so it may be changed to suit the situation.
On a system like OSX you might not have pgrep so you can try this appraoch, when looking for processes by name:
while ps axg | grep process_name$ > /dev/null; do sleep 1; done
The $ symbol at the end of the process name ensures that grep matches only process_name to the end of line in the ps output and not itself.
Is there any builtin feature in Bash to wait for a process to finish?
The wait command only allows one to wait for child processes to finish.
I would like to know if there is any way to wait for any process to finish before proceeding in any script.
A mechanical way to do this is as follows but I would like to know if there is any builtin feature in Bash.
while ps -p `cat $PID_FILE` > /dev/null; do sleep 1; done
To wait for any process to finish
Linux (doesn't work on Alpine, where ash doesn't support tail --pid):
tail --pid=$pid -f /dev/null
Darwin (requires that $pid has open files):
lsof -p $pid +r 1 &>/dev/null
With timeout (seconds)
Linux:
timeout $timeout tail --pid=$pid -f /dev/null
Darwin (requires that $pid has open files):
lsof -p $pid +r 1m%s -t | grep -qm1 $(date -v+${timeout}S +%s 2>/dev/null || echo INF)
There's no builtin. Use kill -0 in a loop for a workable solution:
anywait(){
for pid in "$#"; do
while kill -0 "$pid"; do
sleep 0.5
done
done
}
Or as a simpler oneliner for easy one time usage:
while kill -0 PIDS 2> /dev/null; do sleep 1; done;
As noted by several commentators, if you want to wait for processes that you do not have the privilege to send signals to, you have find some other way to detect if the process is running to replace the kill -0 $pid call. On Linux, test -d "/proc/$pid" works, on other systems you might have to use pgrep (if available) or something like ps | grep "^$pid ".
I found "kill -0" does not work if the process is owned by root (or other), so I used pgrep and came up with:
while pgrep -u root process_name > /dev/null; do sleep 1; done
This would have the disadvantage of probably matching zombie processes.
This bash script loop ends if the process does not exist, or it's a zombie.
PID=<pid to watch>
while s=`ps -p $PID -o s=` && [[ "$s" && "$s" != 'Z' ]]; do
sleep 1
done
EDIT: The above script was given below by Rockallite. Thanks!
My orignal answer below works for Linux, relying on procfs i.e. /proc/. I don't know its portability:
while [[ ( -d /proc/$PID ) && ( -z `grep zombie /proc/$PID/status` ) ]]; do
sleep 1
done
It's not limited to shell, but OS's themselves do not have system calls to watch non-child process termination.
FreeBSD and Solaris have this handy pwait(1) utility, which does exactly, what you want.
I believe, other modern OSes also have the necessary system calls too (MacOS, for example, implements BSD's kqueue), but not all make it available from command-line.
From the bash manpage
wait [n ...]
Wait for each specified process and return its termination status
Each n may be a process ID or a job specification; if a
job spec is given, all processes in that job's pipeline are
waited for. If n is not given, all currently active child processes
are waited for, and the return status is zero. If n
specifies a non-existent process or job, the return status is
127. Otherwise, the return status is the exit status of the
last process or job waited for.
Okay, so it seems the answer is -- no, there is no built in tool.
After setting /proc/sys/kernel/yama/ptrace_scope to 0, it is possible to use the strace program. Further switches can be used to make it silent, so that it really waits passively:
strace -qqe '' -p <PID>
All these solutions are tested in Ubuntu 14.04:
Solution 1 (by using ps command):
Just to add up to Pierz answer, I would suggest:
while ps axg | grep -vw grep | grep -w process_name > /dev/null; do sleep 1; done
In this case, grep -vw grep ensures that grep matches only process_name and not grep itself. It has the advantage of supporting the cases where the process_name is not at the end of a line at ps axg.
Solution 2 (by using top command and process name):
while [[ $(awk '$12=="process_name" {print $0}' <(top -n 1 -b)) ]]; do sleep 1; done
Replace process_name with the process name that appears in top -n 1 -b. Please keep the quotation marks.
To see the list of processes that you wait for them to be finished, you can run:
while : ; do p=$(awk '$12=="process_name" {print $0}' <(top -n 1 -b)); [[ $b ]] || break; echo $p; sleep 1; done
Solution 3 (by using top command and process ID):
while [[ $(awk '$1=="process_id" {print $0}' <(top -n 1 -b)) ]]; do sleep 1; done
Replace process_id with the process ID of your program.
Blocking solution
Use the wait in a loop, for waiting for terminate all processes:
function anywait()
{
for pid in "$#"
do
wait $pid
echo "Process $pid terminated"
done
echo 'All processes terminated'
}
This function will exits immediately, when all processes was terminated. This is the most efficient solution.
Non-blocking solution
Use the kill -0 in a loop, for waiting for terminate all processes + do anything between checks:
function anywait_w_status()
{
for pid in "$#"
do
while kill -0 "$pid"
do
echo "Process $pid still running..."
sleep 1
done
done
echo 'All processes terminated'
}
The reaction time decreased to sleep time, because have to prevent high CPU usage.
A realistic usage:
Waiting for terminate all processes + inform user about all running PIDs.
function anywait_w_status2()
{
while true
do
alive_pids=()
for pid in "$#"
do
kill -0 "$pid" 2>/dev/null \
&& alive_pids+="$pid "
done
if [ ${#alive_pids[#]} -eq 0 ]
then
break
fi
echo "Process(es) still running... ${alive_pids[#]}"
sleep 1
done
echo 'All processes terminated'
}
Notes
These functions getting PIDs via arguments by $# as BASH array.
Had the same issue, I solved the issue killing the process and then waiting for each process to finish using the PROC filesystem:
while [ -e /proc/${pid} ]; do sleep 0.1; done
There is no builtin feature to wait for any process to finish.
You could send kill -0 to any PID found, so you don't get puzzled by zombies and stuff that will still be visible in ps (while still retrieving the PID list using ps).
If you need to both kill a process and wait for it finish, this can be achieved with killall(1) (based on process names), and start-stop-daemon(8) (based on a pidfile).
To kill all processes matching someproc and wait for them to die:
killall someproc --wait # wait forever until matching processes die
timeout 10s killall someproc --wait # timeout after 10 seconds
(Unfortunately, there's no direct equivalent of --wait with kill for a specific pid).
To kill a process based on a pidfile /var/run/someproc.pid using signal SIGINT, while waiting for it to finish, with SIGKILL being sent after 20 seconds of timeout, use:
start-stop-daemon --stop --signal INT --retry 20 --pidfile /var/run/someproc.pid
Use inotifywait to monitor some file that gets closed, when your process terminates. Example (on Linux):
yourproc >logfile.log & disown
inotifywait -q -e close logfile.log
-e specifies the event to wait for, -q means minimal output only on termination. In this case it will be:
logfile.log CLOSE_WRITE,CLOSE
A single wait command can be used to wait for multiple processes:
yourproc1 >logfile1.log & disown
yourproc2 >logfile2.log & disown
yourproc3 >logfile3.log & disown
inotifywait -q -e close logfile1.log logfile2.log logfile3.log
The output string of inotifywait will tell you, which process terminated. This only works with 'real' files, not with something in /proc/
Rauno Palosaari's solution for Timeout in Seconds Darwin, is an excellent workaround for a UNIX-like OS that does not have GNU tail (it is not specific to Darwin). But, depending on the age of the UNIX-like operating system, the command-line offered is more complex than necessary, and can fail:
lsof -p $pid +r 1m%s -t | grep -qm1 $(date -v+${timeout}S +%s 2>/dev/null || echo INF)
On at least one old UNIX, the lsof argument +r 1m%s fails (even for a superuser):
lsof: can't read kernel name list.
The m%s is an output format specification. A simpler post-processor does not require it. For example, the following command waits on PID 5959 for up to five seconds:
lsof -p 5959 +r 1 | awk '/^=/ { if (T++ >= 5) { exit 1 } }'
In this example, if PID 5959 exits of its own accord before the five seconds elapses, ${?} is 0. If not ${?} returns 1 after five seconds.
It may be worth expressly noting that in +r 1, the 1 is the poll interval (in seconds), so it may be changed to suit the situation.
On a system like OSX you might not have pgrep so you can try this appraoch, when looking for processes by name:
while ps axg | grep process_name$ > /dev/null; do sleep 1; done
The $ symbol at the end of the process name ensures that grep matches only process_name to the end of line in the ps output and not itself.