Process exists:
antonshuvalov 21770 0.0 0.0 2432784 476 s003 R+ 12:39AM 0:00.00 grep clusterize master
but if I try to execute
ps -eo pid,comm | grep "clusterize maste"
I get no pid
And if I try to execute
ps -eo pid,comm | grep "clusterize mast"
I get the pid!
Related
This question already has answers here:
How to get process ID of background process?
(9 answers)
Closed 1 year ago.
Below is the output of executing two commands ads2 svcd& and ps -aux|grep ads2
nvidia#nvidia-desktop:~$ ads2 svcd&
[1] 4593
nvidia#nvidia-desktop:~$ ps -aux|grep ads2
nvidia 4593 0.5 0.0 39796 23864 pts/0 Sl 08:20 0:00 /opt/ads2/arm-
linux64/bin/ads2svcd
nvidia 4603 0.0 0.0 6092 672 pts/0 S+ 08:20 0:00 grep --color=auto ads2
nvidia#nvidia-desktop:~$
nvidia#nvidia-desktop:~$
the command ads2 svcd& runs a process related to ads2 software. with ps -aux|grep ads2 i displayed the whole processes that contains the name "ads2".
Now What i'm trying to do is to get the process number of the ads2 which in this example is 4593. So i wrote the follwing bash script:
#!/usr/bin/env bash
process="$(ps -aux|grep ads | grep 'nvidia' | cut -d' ' -f 3)"
echo "The current ads2 process is " $process
The bash script outputs the following:
nvidia#nvidia-desktop:~$ ./test.sh
The current ads2 process is
As you see the process number is not filtered. So what i'm i doing wrong?
thanks in advance
List all the processes in the current shell with $$ built-in variable
ps --forest -gp $$
PID TTY STAT TIME COMMAND
3809 pts/1 Ss 0:01 bash
4896 pts/1 T 0:00 \_ vim file.json
22965 pts/1 S+ 0:00 \_ ssh dw
3607 pts/0 Ss 0:01 bash
2500 pts/0 R+ 0:00 \_ ps --forest -gp 3607
3327 tty2 Ssl+ 0:00 /usr/lib/gdm3/gdm-x-session --run-script i3
3329 tty2 Sl+ 8:12 \_ /usr/lib/xorg/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -background none -noreset -keeptty -verbose 3
3346 tty2 S+ 0:03 \_ i3
Just see the pid of them:
ps -opid --forest -gp $$
PID
3809
4896
22965
3607
2688
3327
3329
3346
If you need to use grep for any reason, use -opid,cmd with current shell:
ps -opid,cmd -gp $$ | grep vim
3851 grep --color=auto vim
4896 vim file.json
For all, just use -e
ps -e -opid,cmd | grep vim
4141 grep --color=auto vim
4896 vim file.json
The complete one, we have to ignore the grep itself:
ps -e -opid,cmd | grep vim | grep -v grep | cut -d' ' -f 2
4896
Without double grep using comm option for ps
ps -opid,comm -gp $$ | grep vim
4896 vim
of course the simplest one is pgrep
pgrep vim
4896
NOTE for variable assignment there should NOT be any space:
# wrong
ads2ProcessId = $(pgrep ads2)
# right
ads2ProcessId=$(pgrep ads2)
I have to do the same thing many times a day:
ps aux
look for process running ssh to one of my servers ...
kill -9 <pid>
I'm looking to see if I can alias process into one line. The output of ps aux is usually something like this:
user 6871 0.0 0.0 4351260 8 ?? Ss 3:28PM 0:05.95 ssh -Nf -L 18881:my-server:18881
user 3018 0.0 0.0 4334292 52 ?? S 12:08PM 0:00.15 /usr/bin/ssh-agent -l
user 9687 0.0 0.0 4294392 928 s002 S+ 10:48AM 0:00.00 grep ssh
I always want to kill the process with the my-server in it.
Does anyone know how I could accomplish this?
for pid in $(ps aux | grep "[m]y-server" | awk '{print $2}'); do kill -9 $pid; done
ps aux | grep "[m]y-server" | awk '{print $2}' - this part gives you list of pids processes that include "my-server". And this script will go through this list and kill all this processes.
I use pgrep -- if you're sure you want to kill all the processes that match:
$ kill -9 `pgrep my-server`
A simple solution is to use pkill:
sudo pkill my-server
I have a bash script (ScreamDaemon.sh) inside which a check that example of it isn't running already is added.
numscr=`ps aux | grep ScreamDaemon.sh | wc -l`;
if [ "${numscr}" -gt "2" ]; then
echo "an instance of ScreamDaemon still running";
exit 0;
fi
Normally, if there are no another copy of script running, ps aux | grep ScreamDaemon.sh | wc -l should return 2 (it should find itself and grep ScreamDaemon.sh), but it returns 3.
So, I try to analyse what happens and after adding some echoes see this:
there are lines I have added into the script
ps aux | grep ScreamDaemon.sh
ps aux | grep ScreamDaemon.sh | wc -l
str=`ps aux | grep ScreamDaemon.sh`
echo $str
numscr=`ps aux | grep ScreamDaemon.sh | wc -l`;
echo $numscr
there is an output:
pamela 27894 0.0 0.0 106100 1216 pts/1 S+ 13:41 0:00 /bin/bash ./ScreamDaemon.sh
pamela 27899 0.0 0.0 103252 844 pts/1 S+ 13:41 0:00 grep ScreamDaemon.sh
2
pamela 27894 0.0 0.0 106100 1216 pts/1 S+ 13:41 0:00 /bin/bash ./ScreamDaemon.sh pamela 27903 0.0 0.0 106100 524 pts/1 S+ 13:41 0:00 /bin/bash ./ScreamDaemon.sh pamela 27905 0.0 0.0 103252 848 pts/1 S+ 13:41 0:00 grep ScreamDaemon.sh
3
I also tried to add the sleep command right inside `ps aux | grep ScreamDaemon.sh; sleep 1m` and see from the parallel terminal how many instances ps aux|grep ScreamDaemon.sh shows:
[pamela#pm03 ~]$ ps aux | grep ScreamDaemon.sh
pamela 28394 0.0 0.0 106100 1216 pts/1 S+ 14:23 0:00 /bin/bash ./ScreamDaemon.sh
pamela 28403 0.0 0.0 106100 592 pts/1 S+ 14:23 0:00 /bin/bash ./ScreamDaemon.sh
pamela 28408 0.0 0.0 103252 848 pts/9 S+ 14:23 0:00 grep ScreamDaemon.sh
So, it seems that
str=`ps aux | grep ScreamDaemon.sh`
contrary to
ps aux | grep ScreamDaemon.sh
found two instances of ScreamDaemon.sh, but why? Where this additional copy of ScreamDaemon.sh come from?
This is an output of pstree -ap command
│ ├─sshd,27806
│ │ └─sshd,27808
│ │ └─bash,27809
│ │ └─ScreamDaemon.sh,28731 ./ScreamDaemon.sh
│ │ └─ScreamDaemon.sh,28740 ./ScreamDaemon.sh
│ │ └─sleep,28743 2m
Why can a single bash script show up multiple times in ps?
This is typical when any constructs which implicitly create a subshell are in play. For instance, in bash:
echo foo | bar
...creates a new forked copy of the shell to run the echo, with its own ps instance. Similarly:
( bar; echo done )
...creates a new subshell, has that subshell run the external command bar, and then has the subshell perform the echo.
Similarly:
foo=$(bar)
...creates a subshell for the command substitution, runs bar in there (potentially exec'ing the command and consuming the subshell, but this is not guaranteed), and reads its output into the parent.
Now, how does this answer your question? Because
result=$(ps aux | grep | wc)
...runs that ps command in a subshell, which itself creates an extra bash instance.
How can I properly ensure that only one copy of my script is running?
Use a lockfile.
See for instance:
How to prevent a script from running simultaneously?
What is the best way to ensure only one instance of a Bash script is running?
Note that I strongly suggest use of a flock-based variant.
Of course, the reason you find an additional process is because:
One process is running the sub-shell (of the command execution `..`)
included in your line: numscr=`ps aux | grep ScreamDaemon.sh | wc -l`;
that's the simplest answer.
However I would like to make some additional suggestions about your code:
First, quote your expansions, it should be: echo "$str".
Not doing so is making several lines collapse into a long one.
Second, you may use: grep [S]creamDaemon.sh to avoid matching the grep command itself.
Third, capture the command just once in a variable, then count lines from the variable. In this case it presents no problem, but for dynamic processes, one capture and the following capture to count could give different results.
Fourth, make an habit of using $(...) command substitutions instead of the more error prone (especially when Nesting) `...`.
### Using a file as the simplest way to capture the output of a command
### that is running in this shell (not a subshell).
ps aux | grep "[S]creamDaemon.sh" > "/tmp/tmpfile$$.txt"
str="$(< "/tmp/tmpfile$$.txt")" ### get the value of var "str"
rm "/tmp/tmpfile$$.txt" ### erase the file used ($$ is pid).
numscr="$(echo "$str" | wc -l)" ### count the number of lines.
echo "$numscr" ### present results.
echo "$str"
str="$( ps aux | grep "[S]creamDaemon.sh" )" ### capture var "str".
numscr="$(echo "$str" | wc -l)" ### count the number of lines.
echo "$numscr" ### present results.
echo "$str"
### The only bashim is the `$(<...)`, change to `$(cat ...)` if needed.
#CharlesDuffy covered the point of a flock quite well, please read it.
I have two java program running on server MyProgram and MyProgramTest.
ps -ef | grep -i java
root 505 17711 0 16:54 pts/4 00:00:00 grep -i MyProgram
root 16450 16448 99 16:46 pts/4 00:07:29 java MyProgram
root 16473 16471 99 16:46 pts/4 00:07:29 java MyProgramTest
I want to search there pid using below commands
ps ax | grep -v grep | grep MyProgram
It should give me PID 16450 but it is giving both
16450 pts/4 Sl 9:19 java MyProgram
16473 pts/4 Sl 9:19 java MyProgramTest
Expected Output :
16450 pts/4 Sl 9:19 java MyProgram
How to get PID by Unique Process Name in linux ?
ps ax | grep -v grep | grep -w "MyProgram"
or
ps ax | grep -v grep | grep "\MyProgram\b"
You can use,
ps ax | grep -v grep | grep -w MyProgram
-w for Whole Word Match. However, It will also match things like MyProgram or MyProgram Hello.
To avoid tricks like grep -v grep it is better to use pgrep:
pgrep --exact MyProgram
Suffix $, ie; the process name ends with "MyProgram",
$ ps -ef |grep MyProgram$
I am trying to kill a process in linux
ps -aux
root 14074 0.0 0.4 6586120 67452 pts/0 Sl 22:45 0:01 java -cp target/cronscheduler-1.0-SNAPSHOT.jar com.cronscheduler.QuartzMain
Kill the process in the stop script using the below command
ps aux | grep "java -cp target/cronscheduler-1.0-SNAPSHOT.jar com.cronscheduler.QuartzMain" | \
grep -v grep | awk '{print $2}' | xargs kill -9
Issue is this command works fine when cronscheduler.QuartzMain is running. But when this process is already killed then the above command throws error
Usage:
kill [options] <pid|name> [...]
Your inputs on removing the errors are appreciated
pkill can search through the complete command line. Try
pkill -9 -f 'java -cp target/cronscheduler-1.0-SNAPSHOT.jar com.cronscheduler.QuartzMain'
Your command may create errors, because it sends more than the pid (the complete line from ps) to kill.
One of the solution I found was to redirect the error message :
cat /etc/*.conf 2> /dev/null
ps aux | grep httpd
httpd 3486 0.0 0.1 4248 1432 ? S Jul31 0:00 /usr/sbin/httpd -f /etc/httpd/httpd.conf
# kill 3486
OR
$ sudo kill 3486
Please try below this will help in clearing the child process id's as well.
for i in `ps -ef| grep "java -cp target/cronscheduler-1.0-SNAPSHOT.jar com.cronscheduler.QuartzMain" | grep -v grep | awk '{print $2}'`
do
ptree $i|awk '{print $1}' >>pids.txt
done
for i in $(cat pids.txt)
do
kill -9 $i
done