I'm trying:
#!/bin/bash
if $(ps -C "bm_d21_debug")
then
kill $(ps -C "bm_d21_debug" -o pid=)
echo "exists"
fi
It returns: "PID: command not found"
Not sure what I'm doing wrong?
Consider this line:
if $(ps -C "bm_d21_debug")
You execute the ps command in a command substitution, which returns the command output. The if command then tries to run that output as a command.
The first word of the ps output is PID, which if will handle as the command name. Thus, the "command not found" error.
You just want
if ps -C "bm_d21_debug" >/dev/null; then
echo running
else
echo NOT running
fi
I suggest to use square brackets also:
if [[ $(ps -C "bm_d21_debug") ]]
But this command will always return "yes" ($? = 0)
Fixed by changing to
if ps aux | grep ./bm_d21_debug | grep -v grep >/dev/null;then
pid=$(ps aux | grep ./bm_d21_debug | grep -v grep | awk '{print $2}')
kill $pid
echo $pid
fi
For a half-finished script that already uses the output of a program I also need the name and the parameters of the program that was used to pipe to my script.
So I run it like this:
yay something | ./myscript
Now I need to store "yay something" into a variable.
There is a way to to get previous runned commands or the current one by using set -o history -o histexpand and echo !! or echo $0 but that doesn't include what I wrote right before the pipe.
Maybe you would suggest to pass the name of the program and it's parameter to my script as parameters and then run it there but I don't want this (pass a command as an argument to bash script).
UPDATED SOLUTION (old below):
#!/bin/bash -i
#get processes
processes=$(> >(ps -f))
echo beginning:
echo "$processes"
#filter bin/bash -i
pac=$(echo "$processes" | sed '1,/bin\/bash -i/!d')
pac=$(echo "$pac" | tail -2 | head -1)
#kill
delete=$(echo $pac | grep -oP "(?<=$USER\s)\w+")
pac=$(echo "$pac" | grep -o -P '(?<=00:00:00).*(?=)')
echo "$delete"
kill -9 "$delete"
#print
echo " "
echo end:
echo "${pac:1}"
Note: When you use echo, man or cat then $pac will be empty.
OLD Text:
Thanks to Charles for his enormous effort and his link that finally led me to processes=$(> >(ps -f)).
Here a working example. You can e.g. use it with vi test | ./testprocesses (or nano or package helpers like yay or trizen but it won't work with echo, man nor with cat):
#!/bin/bash -i
#get processes
processes=$(> >(ps -f))
echo beginning:
echo $processes
#filter
pac=$(echo $processes | grep -o -P '(?<=CM).*(?=testprocesses)' | grep -o -P '(?<=D).*(?=testprocesses)' | grep -o -P "(?<=00:00:00).*(?=$USER)")
#kill
delete=$(echo $pac | grep -oP "(?<=$USER\s)\w+")
pac=$(echo $pac | grep -o -P '(?<=00:00:00).*(?=)')
kill -9 $delete
#print
echo " "
echo end:
echo $pac
The kill part is necessary to kill the vi instance else it will still be running and eventually interfer with future executions of the script.
GNU bash, version 1.14.7(1)
I have a script is called "abc.sh"
I have to check this from abc.sh script only...
inside it I have written following statement
status=`ps -efww | grep -w "abc.sh" | grep -v grep | grep -v $$ | awk '{ print $2 }'`
if [ ! -z "$status" ]; then
echo "[`date`] : abc.sh : Process is already running"
exit 1;
fi
I know it's wrong because every time it exits as it found its own process in 'ps'
how to solve it?
how can I check that script is already running or not from that script only ?
An easier way to check for a process already executing is the pidof command.
if pidof -x "abc.sh" >/dev/null; then
echo "Process already running"
fi
Alternatively, have your script create a PID file when it executes. It's then a simple exercise of checking for the presence of the PID file to determine if the process is already running.
#!/bin/bash
# abc.sh
mypidfile=/var/run/abc.sh.pid
# Could add check for existence of mypidfile here if interlock is
# needed in the shell script itself.
# Ensure PID file is removed on program exit.
trap "rm -f -- '$mypidfile'" EXIT
# Create a file with current PID to indicate that process is running.
echo $$ > "$mypidfile"
...
Update:
The question has now changed to check from the script itself. In this case, we would expect to always see at least one abc.sh running. If there is more than one abc.sh, then we know that process is still running. I'd still suggest use of the pidof command which would return 2 PIDs if the process was already running. You could use grep to filter out the current PID, loop in the shell or even revert to just counting PIDs with wc to detect multiple processes.
Here's an example:
#!/bin/bash
for pid in $(pidof -x abc.sh); do
if [ $pid != $$ ]; then
echo "[$(date)] : abc.sh : Process is already running with PID $pid"
exit 1
fi
done
I you want the "pidof" method, here is the trick:
if pidof -o %PPID -x "abc.sh">/dev/null; then
echo "Process already running"
fi
Where the -o %PPID parameter tells to omit the pid of the calling shell or shell script. More info in the pidof man page.
Here's one trick you'll see in various places:
status=`ps -efww | grep -w "[a]bc.sh" | awk -vpid=$$ '$2 != pid { print $2 }'`
if [ ! -z "$status" ]; then
echo "[`date`] : abc.sh : Process is already running"
exit 1;
fi
The brackets around the [a] (or pick a different letter) prevent grep from finding itself. This makes the grep -v grep bit unnecessary. I also removed the grep -v $$ and fixed the awk part to accomplish the same thing.
Working solution:
if [[ `pgrep -f $0` != "$$" ]]; then
echo "Another instance of shell already exist! Exiting"
exit
fi
Edit: I checked out some comments lately, so I tried attempting same with some debugging. I will also will explain it.
Explanation:
$0 gives filename of your running script.
$$ gives PID of your running script.
pgrep searches for process by name and returns PID.
pgrep -f $0 searches by filename, $0 being the current bash script filename and returns its PID.
So, pgrep checks if your script PID ($0) is equal to current running script ($$). If yes, then the script runs normally. If no, that means there's another PID with same filename running, so it exits. The reason I used pgrep -f $0 instead of pgrep bash is that you could have multiple instances of bash running and thus returns multiple PIDs. By filename, its returns only single PID.
Exceptions:
Use bash script.sh not ./script.sh as it doesn't work unless you have shebang.
Fix: Use #!/bin/bash shebang at beginning.
The reason sudo doesn't work is that it returns pgrep returns PID of both bash and sudo, instead of returning of of bash.
Fix:
#!/bin/bash
pseudopid="`pgrep -f $0 -l`"
actualpid="$(echo "$pseudopid" | grep -v 'sudo' | awk -F ' ' '{print $1}')"
if [[ `echo $actualpid` != "$$" ]]; then
echo "Another instance of shell already exist! Exiting"
exit
fi
while true
do
echo "Running"
sleep 100
done
The script exits even if the script isn't running. That is because there's another process having that same filename. Try doing vim script.sh then running bash script.sh, it'll fail because of vim being opened with same filename
Fix: Use unique filename.
Someone please shoot me down if I'm wrong here
I understand that the mkdir operation is atomic, so you could create a lock directory
#!/bin/sh
lockdir=/tmp/AXgqg0lsoeykp9L9NZjIuaqvu7ANILL4foeqzpJcTs3YkwtiJ0
mkdir $lockdir || {
echo "lock directory exists. exiting"
exit 1
}
# take pains to remove lock directory when script terminates
trap "rmdir $lockdir" EXIT INT KILL TERM
# rest of script here
Here's how I do it in a bash script:
if ps ax | grep $0 | grep -v $$ | grep bash | grep -v grep
then
echo "The script is already running."
exit 1
fi
This allows me to use this snippet for any bash script. I needed to grep bash because when using with cron, it creates another process that executes it using /bin/sh.
I find the answer from #Austin Phillips is spot on. One small improvement I'd do is to add -o (to ignore the pid of the script itself) and match for the script with basename (ie same code can be put into any script):
if pidof -x "`basename $0`" -o $$ >/dev/null; then
echo "Process already running"
fi
pidof wasn't working for me so I searched some more and came across pgrep
for pid in $(pgrep -f my_script.sh); do
if [ $pid != $$ ]; then
echo "[$(date)] : my_script.sh : Process is already running with PID $pid"
exit 1
else
echo "Running with PID $pid"
fi
done
Taken in part from answers above and https://askubuntu.com/a/803106/802276
Use the PS command in a little different way to ignore child process as well:
ps -eaf | grep -v grep | grep $PROCESS | grep -v $$
I create a temporary file during execution.
This is how I do it:
#!/bin/sh
# check if lock file exists
if [ -e /tmp/script.lock ]; then
echo "script is already running"
else
# create a lock file
touch /tmp/script.lock
echo "run script..."
#remove lock file
rm /tmp/script.lock
fi
I have found that using backticks to capture command output into a variable, adversly, yeilds one too many ps aux results, e.g. for a single running instance of abc.sh:
ps aux | grep -w "abc.sh" | grep -v grep | wc -l
returns "1". However,
count=`ps aux | grep -w "abc.sh" | grep -v grep | wc -l`
echo $count
returns "2"
Seems like using the backtick construction somehow temporarily creates another process. Could be the reason why the topicstarter could not make this work. Just need to decrement the $count var.
I didn't want to hardcode abc.sh in the check, so I used the following:
MY_SCRIPT_NAME=`basename "$0"`
if pidof -o %PPID -x $MY_SCRIPT_NAME > /dev/null; then
echo "$MY_SCRIPT_NAME already running; exiting"
exit 1
fi
This is compact and universal
# exit if another instance of this script is running
for pid in $(pidof -x `basename $0`); do
[ $pid != $$ ] && { exit 1; }
done
The cleanest fastest way:
processAlreadyRunning () {
process="$(basename "${0}")"
pidof -x "${process}" -o $$ &>/dev/null
}
For other variants (like AIX) that don't have pidof or pgrep. Reliability is greatly improved by getting a "static" view of the process table as opposed to piping it directly to grep. Setting IFS to null will preserve the carriage returns when the ps output is assigned to a variable.
#!/bin/ksh93
IFS=""
script_name=$(basename $0)
PSOUT="$(ps ax)"
ANY_TEXT=$(echo $PSOUT | grep $script_name | grep -vw $$ | grep $(basename $SHELL))
if [[ $ANY_TEXT ]]; then
echo "Process is already running"
echo "$ANY_TEXT"
exit
fi
[ "$(pidof -x $(basename $0))" != $$ ] && exit
https://github.com/x-zhao/exit-if-bash-script-already-running/blob/master/script.sh
Here is my shell script:
#!/bin/bash
PIDS=$(ps -e | grep $1 |grep -v grep| awk '{print $1}')
kill -s SIGINT $PIDS
echo "Done sendings signal"
I am passing the name of the process as command line argument.
The echo command is not getting executed, although the target processes are actually receiving the SIGINT signal and exited.
Any suggestions?
Update:
I changed the code to:
#!/bin/bash
PIDS=$(ps -e |grep $1 | grep -v grep | awk '{print $1}'|grep -v $$)
echo $PIDS
kill -s SIGINT $PIDS
echo "Done sendings signal"
echo "The current process is $$"
Now I am noticing a strange thing:
The script is working but not as expected. Executing following command in command line outside the script
ps -e|grep process-name|grep -v grep|awk '{print $1}'|grep -v $$
gives pid of the process-name but when I execute the same command inside shell script, assign it to variable PIDS and then echo PIDS then it shows one more pid in addition to the pid of process-name. Therefore when the kill command executes it gives an error that the process with second pid doesn't exist. It does echo the remaining sentences in the terminal. Any clue ?
There really are only a couple of possibilities. Assuming you're just running this from the command line, you should see the message ... unless, of course, what you're doing puts the PID of your shell process in PIDS, in which case the kill would kill the (sub) shell running your command before you hit the echo.
Suggestion: echo $PIDS before you call kill and see what's there. In fact, I'd be tempted to comment out the kill and try the command, just to see what happens.
#!/bin/bash
PIDS=$(ps -e | grep $1 |grep -v grep| awk '{print $1}')
echo $PIDS
# kill -s SIGINT $PIDS
echo "Done sendings signal"
Of course, you can always run the script with bash -x to see everything.
Your script works. The only reason I can see for the echo not being executed is that some value of $1 and the script file name combine so that your script PID is also gathered, thereby making the script suicide.
The PIDS line spawns a process running ps, grep, another grep -- so you won't find in PIDS the processes running grep, but what about the parent process itself?
Try:
#!/bin/bash
PIDS=$(ps -e | grep $1 |grep -v grep | awk '{print $1}' | grep -v "^$$\$" )
kill -s SIGINT $PIDS
echo "Done sendings signal"
or run the pipes one after the other with suitable safety greps.
Edit: it is evident that the "$1" selection is selecting too much. So I'd rewrite the script like this:
#!/bin/bash
# Gather the output of "ps -e". This will also gather the PIDs of this
# process and of ps process and its subshell.
PSS=$( ps -e )
# Extract PIDs, excluding this one PID and excluding a process called "ps".
# Don't need to expunge 'grep' since no grep was running when getting PSS.
PIDS=$( echo "$PSS" | grep -v "\<ps\>" | grep "$1" | awk '{print $1}' | grep -v "^$$\$" )
if [ -n "$PIDS" ]; then
kill -s SIGINT $PIDS
else
echo "No process found matching $1"
fi
echo "Done sending signal."
ps -e is identical to ps -A and selects all processes ( cf. http://linux.die.net/man/1/ps ), i. e. ps -e displays "information about other users' processes, including those without controlling terminals" (Mac OS X man page of ps). This means you will also kill the PID ($$) of your shell process, as already pointed out by Charlie Martin, because you will also grep a line of output of the ps -e command that looks like so:
67988 ttys000 0:00.00 /bin/bash ./killpids sleep
Just log the output of ps -e to a file to see that your script commits suicide:
./killpids sleep 2>err.log
#!/bin/bash
# cat killpids
echo $$
for n in {1..10}; do
sleep 5000 &
done
sleep 1
unset PIDS
PIDS="$(ps -e | tee /dev/stderr | grep "$1" | grep -v grep | awk '{print $1}')"
#PIDS="$(ps -www -U $USER -o pid,uid,comm | tee /dev/stderr | grep "$1" | grep -v grep | awk '{print $1}')"
wc -l <<<"$PIDS"
#kill -s SIGINT $PIDS
echo kill -s TERM $PIDS
kill -s TERM $PIDS
echo "Done sendings signal"
I need to implement a shell script that kills a process. The problem is that I need to do a conditional to be able to see if the process is running or not.
This is my code, but it is not working:
#!/bin/sh
if [ -x "MY_PROCCESS_NAME"]; then
killall MY_PROCCESS_NAME
else
echo "Doesn't exist"
fi
This is the error:
line 3: [: missing `]'
to check if a process is running on mac os x you can use:
pid=$(ps -fe | grep 'process name' | grep -v grep | awk '{print $2}')
if you want to reduce the number of shell scripts you can enclose one of the characters of the name of the process in square brackets:
pid=$(ps -fe | grep '[p]rocess name' | awk '{print $2}')
combined in your test this would look like:
pid=$(ps -fe | grep '[p]rocess name' | awk '{print $2}')
if [[ -n $pid ]]; then
kill $pid
else
echo "Does not exist"
fi
it's a little more complicated than you would need to do under linux as you generally have the 'pgrep' command, which is the rough equivalent of the 'ps -fe | grep ... | grep -v grep'
not sure if it would work in OSX, it works in ubuntu.
but as a one liner:
ps aux | awk '$11~/vim/ {PID = $2} END {if (PID) print "kill -9 "PID; else print "echo no process"}' | bash
what it does is it finds a process, in this case, vim and returns the kill -9 pid if no string is found it returns echo no process it then pipes the output to bash.